47 PRESERVATION 

BRIEFS 

Maintaining the Exteriors of Small and 

Medium Size Historic Buildings 

Sharon C. Park, FAIA 

National Park Service 

U.S. Department of the Interior 

Preservation is defined as "the act or process of applying 

measures necessary to sustain the existing form, integrity, 

and materials of an historic property. Work, including 

preliminary measures to protect and stabilize the 

property, generally focuses upon the ongoing maintenance 

and repair of historic materials and features rather than 

extensive replacement and new construction."1 

Maintenance helps preserve the integrity of historic 

structures. If existing materials are regularly maintained 

and deterioration is significantly reduced or prevented, 

the integrity of materials and workmanship of the 

building is protected. Proper maintenance is the most 

cost effective method of extending the life of a building. 

As soon as a building is constructed, restored, or 

rehabilitated, physical care is needed to slow the natural 

process of deterioration. An older building has already 

experienced years of normal weathering and may have 

suffered from neglect or inappropriate work as well. 

Decay is inevitable but deterioration can accelerate when 

the building envelope is not maintained on a regular 

basis. Surfaces and parts that were seamlessly joined 

when the building was constructed may gradually 

become loose or disconnected; materials that were once 

sound begin to show signs of weathering. If maintenance 

is deferred, a typical response is to rush in to fix what has 

been ignored, creating additional problems. Work done 

on a crisis level can favor inappropriate treatments that 

alter or damage historic material. 

There are rewards for undertaking certain repetitive tasks 

consistently according to a set schedule. Routine and 

preventive care of building materials is the most effective 

way of slowing the natural process of deterioration. 

The survival of historic buildings in good condition is 

primarily due to regular upkeep and the preservation of 

historic materials. 

Well-maintained properties tend to suffer less damage 

from storms, high winds, and even small earthquakes. 

Keeping the roof sound, armatures and attachments such 

as shutters tightened and secured, and having joints and 

connections functioning well, strengthens the ability of 

older buildings to withstand natural occurrences. 

Over time, the cost of maintenance is substantially less 

than the replacement of deteriorated historic features 

and involves considerably less disruption. Stopping 

decay before it is widespread helps keep the scale and 

complexity of work manageable for the owner. 

This Preservation Brief is designed for those responsible 

for the care of small and medium size historic 

buildings, including owners, property administrators, 

in-house maintenance staff, volunteers, architects, 

and maintenance contractors. The Brief discusses the 

benefits of regular inspections, monitoring, and seasonal 

maintenance work; provides general guidance on 

maintenance treatments for historic building exteriors; 

and emphasizes the importance of keeping a written 

record of completed work. 

Getting Started 

Understanding how building materials and construction 

details function will help avoid treatments that are 

made in an attempt to simplify maintenance but which 

may also result in long-term damage. It is enticing to 

read about "maintenance free" products and systems, 

particularly waterproof sealers, rubberized paints, 

and synthetic siding, but there is no such thing as 

maintenance free when it comes to caring for historic 

buildings. Some approaches that initially seem to 

reduce maintenance requirements may over time 

actually accelerate deterioration. 

Exterior building components, such as roofs, walls, 

openings, projections, and foundations, were often 

constructed with a variety of functional features, 

such as overhangs, trim pieces, drip edges, ventilated 

cavities, and painted surfaces, to protect against water 

infiltration, ultraviolet deterioration, air infiltration, and 

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Figure 1. Maintenance involves selecting 

the proper treatment and protecting adjacent 

surfaces. Using painter's tape to mask around 

a brass doorknocker protects the painted door 

surface from damage when polishing with 

chemical compounds. On the other hand, 

hardware with a patinated finish was not 

intended to be polished and should simply be 

cleaned with a damp cloth. 

Cautions During Maintenance Work 

All maintenance work requires attention to safety of 

the workers and protection of the historic structure. 

Examples include the following: 

• Care should be taken when working with 

historic materials containing lead-based paint. For 

example, damp methods may be used for sanding 

and removal to minimize air-borne particles. 

Special protection is required for workers and 

appropriate safety measures should be followed. 

• Materials encountered during maintenance 

work, such as droppings from pigeons and mice, 

can cause serious illnesses. Appropriate safety 

precautions need to be followed. Services of a 

licensed contractor should be obtained to remove 

large deposits from attics and crawlspaces. 

• Heat removal of paint involves several potential 

safety concerns. First, heating of lead-containing 

paint requires special safety precautions for 

workers. Second, even at low temperature levels, 

heat removal of paint runs the risk of igniting 

debris in walls. Heat should be used only with 

great caution with sufficient coverage by smoke 

detectors in work areas. Work periods need to 

be timed to allow monitoring after completion of 

paint removal each day, since debris will most often 

smolder for a length of time before breaking out 

into open flame. The use of torches, open flames, or 

high heat should be avoided. 

• Many chemical products are hazardous and 

volatile organic compounds (VOC) are banned in 

many areas. If allowed, appropriate respirators and 

other safety precautions are essential for use. 

• Personal protection is importan and may require 

the use of goggles, gloves, mask, closed-toed shoes, 

and a hard hat. 

• Electrical service should be turned off before 

inspecting a basement after a flood or heavy rain, 

where there is high standing water. 

pest infestation. Construction assemblies and joints 

between materials allow for expansion and contraction 

and the diffusion of moisture vapor, while keeping 

water from penetrating the building envelope. Older 

buildings use such features effectively and care must be 

taken to retain them, avoiding the temptation to reduce 

air infiltration or otherwise alter them. 

Monitoring, inspections, and maintenance should all 

be undertaken with safety in mind. Besides normal 

safety procedures, it is important to be cognizant of 

health issues more commonly encountered with older 

buildings, such as lead-based paint, asbestos, and bird 

droppings, and to know when it is necessary to seek 

professional services (see sidebar). 

Original building features and examples of special 

craftsmanship should be afforded extra care. The 

patina or aging of historic materials is often part of 

the charm and character of historic buildings. In such 

cases, maintenance should avoid attempts to make 

finishes look new by over-cleaning or cladding existing 

materials. As with any product that has the potential 

to harm historic materials, the selection of a cleaning 

procedure should always involve testing in a discreet 

location on the building to ensure that it will not abrade, 

fade, streak, or otherwise damage the substrate (Fig 1). 
Maintenance Plan, Schedules and Inspection 

Organizing related work into a written set of 

procedures, or a Maintenance Plan, helps eliminate 

duplication, makes it easier to coordinate work effort, 

and creates a system for prioritizing maintenance 

tasks that takes into account the most vulnerable and 

character-defining elements. 

The first time a property owner or manager establishes 

a maintenance plan or program, it is advisable to 

have help from a preservation architect, preservation 

consultant, and/or experienced contractor. Written 

procedures should outline step-by-step approaches that 

are custom- tailored to a building. No matter how small 

the property, every historic site should have a written 

guide for maintenance that can be as simple as: 

1) Schedules and checklists for inspections; 

2) Forms for recording work, blank base plans and 

elevations to be filled in during inspections and 

upon completion of work; 

3) A set of base-line photographs to be augmented 

over time; 

4) Current lists of contractors for help with complex 

issues or in case of emergencies; 

5) Written procedures for the appropriate care 

of specific materials, including housekeeping, 

routine care, and preventive measures; 

6) Record-keeping sections for work completed, 

costs, warranty cards, sample paint colors, and 

other pertinent material. 

This information can be kept in one or more formats, 

such as a three-ring binder, file folders, or a computer 

Cyclic Building Inspection Checklist: Horse Stable 

Building Feature Material(s) Condition Description 

ROOF: 

Covering Clay tile Two slipped tiles 

database. It is important to keep the files current with 

completed work forms to facilitate long-term evaluations 

and planning for future work (Fig 2). 

Proper maintenance depends on an organized plan with 

work prescribed in manageable components. Regular 

maintenance needs to be considered a priority both in 

terms of time allotted for inspections and for allocation 

of funding. 

Maintenance work scheduling is generally based 

on a variety of factors, including the seriousness 

of the problem, type of work involved, seasonal 

appropriateness, product manufacturer's 

recommendations, and staff availability. There are 

other variables as well. For example, building materials 

and finishes on southern and western exposures will 

often weather faster than those on northern or eastern 

exposures. Horizontal surfaces facing skyward usually 

require greater maintenance than vertical ones; in 

regions with moderate or heavy rainfall, wood and 

other materials in prolonged shadow are subject to 

more rapid decay. 

Maintenance costs can be controlled, in part, through 

careful planning, identification of the amount of 

labor required, and thoughtful scheduling of work. 

Maintenance schedules should take into account 

daily and seasonal activities of the property in order 

to maximize the uninterrupted time necessary to 

complete the work. Institutions generally need to 

budget annually between 2 and 4 percent of the 

replacement value of the building to underwrite 

the expense of full building maintenance. 2 Use of 

trained volunteers to undertake maintenance can 

help reduce costs. 

Exterior inspections usually proceed from the roof 

down to the foundation, working on one elevation at 

Inspection date: 04/24/05 

Maintenance Action Required Work Done 

Reattach tiles 5/4/05 

Painted metal standing seam Slight corrosion; blistering paint on Sand and repaint area that is peeling 6/8/05 

metal roof section 

Flashing Painted metal Flashing in good condition N/A N/A 

Gutters! 6" half round galvanized metal Gutter sagging; downspouts OK Realign gutter and put on new hanger strap 5/4/05 

Downspouts 

Flush out downspouts 5/5/05 

Chimneys No masonry chimney N/A N/A N/A 

Attachments! Metal vent stack and Vent stack hood has some peeling Sand and repaint vent stack 6/8/05 

Penetrations weathervane paint; vane OK 

Figure 2. All personnel associated with a historic structure need to become acquainted with how existing building features should appear and during 

their daily or weekly routines look for changes that may occur. This will help augment the regular maintenance inspection that will occur at specified 

intervals based on seasonal changes, use, and other factors. A segment of an inspection form showing the roof elements of a horse stable is shown. The 

inspection report should be kept along with the maintenance plan and other material in notebook, file or electronic form . 

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a time, moving around the building in a consistent 

direction. On the interior, the attic, inside surfaces of 

exterior walls, and crawlspaces or basements should 

be examined for signs of potential or existing problems 

with the building envelope. 

The following chart lists suggested inspection 

frequencies for major features associated with the 

building's exterior, based on a temperate four-season 

climate and moderate levels of annual rainfall. For areas 

of different climate conditions and rainfall, such as in 

the more arid southwest, the nature of building decay 

and frequency of inspections will vary. For buildings 

with certain inherent conditions, heavy use patterns, or 

locations with more extreme weather conditions, the 

frequency of inspections should be altered accordingly. 

Note: All building features should be inspected after any 

significant weather event such as a severe rainstorm or 

unusually high winds. 

INSPECTION FREQUENCY CHART 

Feature Minimum Inspection Season 

Frequency 

Roof Annually Spring or fall; every 

5 years by roofer 

Chimneys Annually Fa II, prior to 

heating season; 

every 5 years by 

mason 

Roof Drainage 6 months; more Before and after 

frequently as needed wet season, during 

heavy rain 

Exterior Walls and Annually Spring, prior 

Porches to summerlfall 

painting season 

Windows Annually Spring, prior 

to summer/fall 

painting season 

Foundation and Annually Spring or during 

Grade wet season 

Building Perimeter Annually Winter, after leaves 

have dropped off 

trees 

Entryways Annually; heavily Spring, prior 

used entries may to summerlfall 

merit greater painting season 

frequency 

Doors 6 months; heavily Spring and fall; 

used entry doors prior to heating/ 

may merit greater cooling seasons 

frequency 

Attic 4 months, or after a Before, during and 

major storm after wet season 

Basement! 4 months, or after a Before, during and 

Crawlspace major storm after rain season 

Survey observations can be recorded on a standardized 

report form and photographs taken as a visual record. 

All deficient conditions should be recorded and placed 

on a written schedule to be corrected or monitored. 

BUILDING COMPONENTS 

For purposes of this discussion, the principal exterior 

surface areas have been divided into five components 

and are presented in order from the roof down to grade. 

While guidance for inspection and maintenance is 

provided for each component, this information is very 

general in nature and is not indeed to be comprehensive 

in scope. Examples have been selected to address some 

typical maintenance needs and to help the reader avoid 

common mistakes. 

Roofs/chimneys 

The roof is designed to keep water out of a building. 

Thus one of the principal maintenance objectives is 

to ensure water flows off the roof and into functional 

gutters and downspouts directly to grade and away 

from the building-and to prevent water from 

penetrating the attic, exterior walls, and basement 

of a building. (Note: Some buildings were designed 

without gutters and thus assessments must be made 

as to whether rain water is being properly addressed 

at the foundation and perimeter grade.) Keeping 

gutters and downspouts cleared of debris is usually 

high on the list of regular maintenance activities (Fig 3). 

Flashing around chimneys, parapets, dormers, and other 

appendages to the roof also merit regular inspection and 

appropriate maintenance when needed. The material 

covering the roof-wood shingles, slate, tile, asphalt, 

sheet metal, rolled roofing-requires maintenance both 

to ensure a watertight seal and to lengthen its service 

life; the type and frequency of maintenance varies with 

the roofing material. Older chimneys and parapets 

also require inspection and maintenance. With the 

exception of cleaning and minor repairs to gutters 

and downspouts, most roof maintenance work will 

necessitate use of an outside contractor. 

Inspection: 

The functioning of gutters and downspouts can be safely 

observed from the ground during rainy weather and 

when winter ice has collected. Binoculars are a useful 

tool in helping to identify potential roofing problems 

from the same safe vantage point. Careful observation 

from grade helps to identify maintenance needs 

between close-up inspections by an experienced roofer. 

Observation from the building interior is also important 

to identify possible leak locations. When access can 

be safely gained to the roof, it is important to wear 

shoes with slip-resistant soles and to use safety ropes. 
necessary, to keep the ladder from 

crushing the gutter. Use a garden 

hose to flush out troughs and 

downspouts. Patch or repair holes 

in gutters using products such as 

fiberglass tape and epoxy adhesive 

in metal gutters. Avoid asphalt 

compounds since acidic material can 

cause further deterioration of metal 

gutters. 

• Correct misaligned gutters and 

adjust, if necessary, so that water 

flows to drains and does not 

pond. If gutter edges sag, consider 

inserting wooden wedges between 

the fascia board and the back of the 

gutter to add support. Seal leaking 

seams or pinholes in gutters and 

elbows. 

Figure 3. Keeping gutters clean of debris can be one of the most important cyclical 

maintenance activities. On this small one-story addition, a garden hose is being used to flush 

out the trough to ensure that the gutter and downspouts are unobstructed. Gutters on most 

small and medium size buildings can be reached with an extension ladder and a garden hose. 

Photo: Bryan Blundell. 

• Broom sweep branch or leaf 

debris away from shingles, valleys, 

and crickets, particularly around 

chimneys and dormers. 

• Where mechanical equipment is 

mounted on flat or low-sloped roofs, 

ensure that access for maintenance 

Depending on the nature of the roof, some common 

conditions of concern to look for are: 

sagging gutters and split downspouts; 

debris accumulating in gutters and valleys; 

overhanging branches rubbing against the roof 

or gutters 

plant shoots growing out of chimneys; 

slipped, missing, cracked, bucking, delaminating, 

peeling, or broken roof coverings; 

deteriorated flashing and failing connections 

at any intersection of roof areas or of roof and 

adjacent wall; 

bubbled surfaces and moisture ponding on flat or 

low sloped roofs; 

evidence of water leaks in the attic; 

misaligned or damaged elements, such as 

decorative cresting, lightning rods, or antennas; 

and 

cracked masonry or dislodged chimney caps. 

Main tenance: 

• Remove leaves and other debris from gutters and 

downspouts. Utilize a ladder with a brace device, if 

can be provided without damaging the roof. Clean out 

trapped leaves and debris from around equipment base 

and consider adding a protective walkway for access. 

• Remove biological growth where it is causing erosion 

or exfoliation of roofing. Use low-pressure garden 

hose water and a natural or nylon scrubbing brush 

to remove such growth, scraping with a plastic putty 

knife or similar wood or plastic tool as needed on 

heavier buildup. Most growth is acidic and while there 

are products designed to kill spores, such as diluted 

chlorine bleach, they should be avoided. Even fairly 

weak formulas can still cause unexpected color changes, 

efflorescence, or over-splash damage to plantings or 

surfaces below the roof. Where appropriate, trim 

adjacent tree branches to increase sunlight on the roof 

since sunlight will deter further biological growth. 

• Re-secure loose flashing at the dormers, chimneys 

or parapets. Clean out old mortar, lead, lead wool, 

or fastening material and make sure that flashing is 

properly inserted into reglet (slot) joints, taking care 

not to damage the substrate. Avoid installing new step 

flashing as a single metal component where multiple 

pieces are required to provide proper waterproofing. 

Also avoid attaching step flashing with mastic or sealant. 

Properly re-bed all step flashing. Use appropriate 

non-ferrous flashing metal or painted metal if needed. 

Since cap, step, valley, cricket, and apron flashings 

each have specific overlap and extension requirements, 

replacement flashing should match the existing material 

unless there has been a proven deficiency. 

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Figure 4. Damage to roofs often requires immediate 

attention. As a temporary measure, this damaged roof tile 

could be replaced with a brown aluminum sheet wedged 

between the existing tiles. Photo: Chad Randl. 

• Repoint joints in chimneys, parapet, or balustrade 

capping stones using a hydraulic lime mortar or other 

suitable mortar where the existing mortar has eroded or 

cracked, allowing moisture penetration. In general, a 

mortar that is slightly weaker than the adjacent masonry 

should be used. This allows trapped moisture in the 

masonry to migrate out through the mortar and not 

the masonry. Spalled masonry is often evidence of the 

previous use of a mortar mix that was too hard. 

• Use professional services to repair chimneys and 

caps. Avoid the use of mortar washes on masonry since 

they tend to crack, allowing moisture to penetrate and 

promoting masonry spalling. Repoint masonry with a 

durable mortar that is slightly weaker than the adjacent 

masonry. Slope the masonry mortar cap to insure 

drainage away from the flue. If a chimney rain cap is 

installed, ensure adequate venting and exhaust. 

• As a temporary measure, slip pieces of non-corrosive 

metal flashing under or between damaged and missing 

roofing units until new slate, shingles, or tile can be 

attached. Repair broken, missing or damaged roofing 

units with ones that match. Follow roofing supplier 

and industry guidance on inserting and attaching 

replacement units (Fig 4). Avoid using temporary 

asphalt patches as it makes a proper repair difficult 

later on. 

• For long-term preservation of wooden shingle roofs 

coated with a preservative, recoat every few years 

following the manufacturer's recommendations. Be 

aware of environmental considerations. 

• Scrape and repaint selected areas of coated ferrous 

metal roofing as needed; repaint on a regularly 

Figure 5. The use of a sealant to close an exposed joint is not always 

an effective long-term solution. Where this decorative wood element 

connects to the slate roof, the sealant has failed within a short time 

and a proper metal flashing collar is being fitted instead. 

Photo: Bryan Blundell. 

scheduled basis. Ferrous metal roofs can last a 

long time if painted regularly. Alkyd coatings are 

generally used on metal roofs; be sure to wash and 

properly prepare the area beforehand. Environmental 

regulations may restrict the use of certain types of 

paints. Apply the coating system in accordance with 

manufacturer's recommendations. Prepare the surface 

prior to application to obtain good adhesion with the 

prime coat. Apply both a prime coat and a topcoat for 

good bonding and coverage; select primer and topcoat 

products from the same manufacturer. 

• Re-secure loose decorative elements, such as finials 

and weathervanes. Seek professional advice if 

decorative elements exhibit considerable corrosion, 

wood rot, or structural instability. Small surface cracks 

may benefit from a flexible sealant to keep moisture 

out; sealants have a limited life and require careful 

inspection and periodic replacement (Fig 5). 

Exterior Walls 

Exterior walls are designed to help prevent water 

infiltration, control air infiltration, and serve as a 

barrier for unwanted animals, birds and insects. 

The primary maintenance objective is to keep 

walls in sound condition and to prevent water 

penetration, insect infestation, and needless decay 

(Fig 6). Depending on the materials and construction 

methods, walls should have an even appearance, free 

from unwanted cracks, and should be able to shed 

excess moisture. Where surfaces are significantly 

misaligned or where there are bulging wall sections 
or cracks indicative of potential structural problems, 

seek professional guidance as to the cause of distress 

and appropriate corrective measures. Wood-frame 

construction generally will require more frequent 

maintenance than buildings constructed of brick, stone, 

or terra cotta (Fig 7). 

Inspections: 

It is best to inspect walls during dryas well as wet 

weather. Look for moisture patterns that may appear 

on the walls after a heavy or sustained rainfall or 

snow, recording any patterns on elevation drawings or 

standard recording forms. Monitoring the interior wall 

for moisture or other potential problems is important 

as well. Look for movement in cracks, joints, and 

around windows and doors and try to establish 

whether movement is seasonal in nature (such as 

related to shrinkage of wood during dry weather) 

or signs of an ongoing problem. For moderate size 

buildings, a ladder or mechanical lift may be necessary, 

though in some cases the use of binoculars and 

observations made from windows and other openings 

will be sufficient. When examining the walls, some 

common conditions of concern to look for are: 

Misaligned surfaces, bulging wall sections, 

cracks in masonry units, diagonal cracks in 

masonry joints, spalling masonry, open joints, 

and nail popping; 

Evidence of wood rot, insect infestation, and 

potentially damaging vegetative growth; 

Deficiencies in the attachment of wall mounted 

lamps, flag pole brackets, signs, and similar 

items; 

Potential problems with penetrating features 

such as water spigots, electrical outlets, and 

vents; 

Excessive damp spots, often accompanied by 

staining, peeling paint, moss, or mold; and 

General paint problems (Fig 8). 

Maintenance: 

• Trim tree branches away from walls. Remove ivy 

and tendrils of climbing plants by first cutting at the 

base of the vine to allow tendrils to die back, and 

later using a plastic scraper to dislodge debris and 

an appropriate digging tool to dislodge and remove 

root systems. Be cautious if using a commercial 

chemical to accelerate root decay; follow safety 

directions and avoid contact of chemicals with 

workers and wall materials. 

• Wash exterior wall surfaces if dirt or other deposits 

are causing damage or hiding deterioration; extend 

Figure 6. Stucco applied to an exterior wall or foundation was intended 

to function as a watertight surface. Unless maintained, rainwater 

will penetrate open joints and cracks that may occur over time. A 

spa lied section of stucco indicates some damage has occurred and a 

wooden mallet is being used to tap the surface to determine whether the 

immediate stucco has lost adhesion. Photo: Bryan Blundell. 

Figure 7. One of the advantages of wood shingles as a wall covering is 

that individual shingles that are damaged can easily be replaced. On 

this highly exposed corner, worn shingles have been selectively replaced 

to help safeguard against water damage. The new shingles will be 

stained to match the existing shingles. 

Figure 8. The paint on the siding of this south-facing wall needs to be 

scraped, sanded, primed and repainted. Postponing such work will lead 

to further paint failure, require greater preparatory costs, and could 

even result in the need to replace some siding. Photo: Charles Fisher. 

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scheduled times for cleaning for cosmetic purposes 

to reduce frequency (Fig 9). When cleaning, use the 

gentlest means possible; start with natural bristle 

brushes and water and only add a mild phosphatefree detergent if necessary. Use non-abrasive cleaning 

methods and low-pressure water from a garden hose. 

For most building materials, such as wood and brick, 

avoid abrasive methods such as mechanical scrapers 

and high-pressure water or air and such additives as 

sand, natural soda, ice crystals, or rubber products. 

All abrasives remove some portion of the surface and 

power-washing drives excessive moisture into wall 

materials and even into wall cavities and interior walls. 

If using a mild detergent, two people are recommended, 

one to brush and one to prewet and rinse. When graffiti 

or stains are present, consult a preservation specialist 

who may use poultices or mild chemicals to remove the 

stain. If the entire building needs cleaning other than 

described above, consult a specialist. 

• Repoint masonry in areas where mortar is loose or 

where masonry units have settled. Resolve cause of 

cracks or failure before resetting units and repointing. 

Rake out joints by hand, generally avoiding rotary saws 

or drills, to a depth of 2 Vz times the width of the joint 

(or until sound mortar is encountered), to make sure 

that fresh mortar will not pop out. Repointing mortar 

should be lime-rich and formulated to be slightly weaker 

than the masonry units and to match the historic mortar 

in color, width, appearance, and tooling. Off-the-shelf 

pre-mixed cement mortars are not appropriate for most 

historic buildings. Avoid use of joint sealants in place of 

Figure 9. To help extend 

a repainting cycle, dirt 

and spider webs should be 

removed before permanent 

staining occurs. In this 

case, a natural bristle brush 

and a soft damp cloth are 

being used to remove insect 

debris and refresh the 

surface appearance. 

mortar on vertical masonry wall surfaces, as they are 

not breathable and can lead to moisture-related damage 

of the adjacent masonry (Fig 10). 

• Correct areas that trap unwanted moisture. Damaged 

bricks or stone units can sometimes be removed, turned 

around, and reset, or replaced with salvaged units. 

When using traditional or contemporary materials for 

patching wood, masonry, metal, or other materials, 

ensure that the materials are compatible with the 

substrate; evaluate strength, vapor permeability, and 

thermal expansion, as well as appearance. 

• When patching is required, select a compatible patch 

material. Prepare substrate and install patch material 

according to manufacturer's recommendations; respect 

existing joints. Small or shallow surface defects may not 

require patching; large or deep surface defects may be 

better addressed by installation of a dutchman unit than 

by patching. 

• Where a damaged area is too large to patch, consider 

replacing the section with in-kind material. For stucco 

and adobe materials, traditional patching formulas are 

recommended. 

• When temporarily removing wood siding to repair 

framing or to tighten corner boards and loose trim, 

reuse the existing siding where possible. Consider 

using stainless steel or high strength aluminum nails 

as appropriate. Putty or fill nail holes flush with siding 

prior to repainting. Back-prime any installed wood with 
Figure 10. Repointing of masonry should usually be approached as 

repair rather than maintenance work in part because of the need for 

a skilled mason familiar with historic mortar. In this case, a moisture 

condition was not corrected and the use of a waterproof coating and 

off-the-shelf Portland cement mortar trapped water and resulted in 

further damage to these 19th century bricks. Photo: NPS files. 

one coat of primer and coat end grain that might be 

exposed with two coats of primer. 

• Prepare, prime, and spot paint areas needing 

repainting. Remember that preparation is the key to a 

successful long lasting paint job. Ensure beforehand 

the compatibility of new and existing paints to avoid 

premature paint failure. Remove loose paint to a 

sound substrate; sand or gently rough surface if needed 

for a good paint bond; wipe clean; and repaint with 

appropriate primer and topcoats. Follow manufacturer's 

recommendations for application of coatings, including 

temperature parameters for paint application. Use top 

quality coating materials. Generally paint when sun is 

not shining directly onto surfaces to be painted. 

• Remove deteriorated caulks and sealants, clean, and 

reapply appropriate caulks and sealants using backer 

rods as necessary. Follow manufacturer's instructions 

regarding preparation and installation. 

• Correct deficiencies in any wall attachments such as 

awning and flag pole anchors, improperly installed 

electrical outlets, or loose water spigots. 

Openings 

Exterior wall openings primarily consist of doors, 

windows, storefronts, and passageways. The major 

maintenance objectives are to retain the functioning 

nature of the opening and to keep in sound condition the 

connection between the opening and the wall in order to 

reduce air and water infiltration. 

Inspection: 

Wall openings are typically inspected from inside as well 

as out. Examinations should include the overall material 

condition; a check for unwanted water penetration, 

insect infiltration, or animal entry; and identification 

of where openings may not be properly functioning. 

Frames should be checked to make sure they are not 

loose and to ascertain whether the intersection between 

the wall and the frame is properly sealed. Secure 

connections of glazing to sash and between sash and 

frames are also important. Particular attention should be 

placed on exposed horizontal surfaces of storefronts and 

window frames as they tend to deteriorate much faster 

than vertical surfaces. Inspections should identify: 

loose frames, doors, sash, shutters, screens, 

storefront components, and signs that present 

safety hazards; 

slipped sills and tipped or cupped thresholds; 

poorly fitting units and storm assemblies, 

misaligned frames, drag marks on thresholds 

from sagging doors and storm doors; 

loose, open, or decayed joints in door and 

window frames, doors and sash, shutters, and 

storefronts; 

loose hardware, broken sash cords/chains, 

worn sash pulleys, cracked awning, shutter 

and window hardware, locking difficulties, and 

deteriorated weatherstripping and flashing; 

broken/cracked glass, loose or missing glazing 

and putty; 

peeling paint, corrosion or rust stains; and 

window well debris accumulation, heavy bird 

droppings, and termite and carpenter ant 

damage. 

Maintenance: 

• Replace broken or missing glass as soon as possible; 

in some cases cracked glass may be repaired using 

specialty glues. For historic crown glass and early 

cylinder glass, a conservation approach should be 

considered to repair limited cracks. Where panes with a 

distinct appearance are missing, specialty glass should 

be obtained to match, with sufficient inventory kept for 

future needs. Avoid using mechanical devices to remove 

old putty and match historic putty bevels or details 

when undertaking work. 

• Reputty window glazing where putty is deteriorated 

or missing. Take care in removing putty so as not to 

crack or break old glass or damage muntins and sash 

frames. Re-glaze with either traditionally formulated 

9 
10 

Figure 11. Glazing putty should be maintained in sound 

condition to prevent unwanted air infiltration and water damage. 

New glazing putty should be pulled tight to the glass and edge of 

the wood, creating a clean bevel that matches the historic glazing. 

oil putties or modern synthetic ones, making sure to 

properly bed the glass and secure with glazing points 

(Fig 11). 

• Clean window glass, door glazing, storefronts, 

transom prism lights, garage doors, and storm panels 

using a mild vinegar and water mixture or a nonalkaline commercial window cleaner. Be cautious 

with compounds that contain ammonia as they may 

stain brass or bronze hardware elements if not totally 

removed. When using a squeegee blade or sponge, 

wipe wet corners with a soft dry cloth. Avoid highpressure washes. 

• Clean handles, locks and similar hardware 

with a soft, damp cloth. Use mineral spirits or 

commercial cleaners very sparingly, as repeated use 

may remove original finishes. Most metal cleaners 

include ammonia that can streak and stain metal, 

so it is important to remove all cleaning residue. 

Polished hardware subject to tarnishing or oxidation, 

particularly doorknobs, often benefits from a thin coat 

of paste wax (carnauba), hand buffed to remove extra 

residue. Avoid lacquer finishes for high use areas, as 

they require more extensive maintenance. Patina ted 

finishes should not be cleaned with any chemicals, 

since the subtle aged appearance contributes to the 

building's character. 

• Remove and clean hardware before painting doors and 

windows; reinstall after the paint has dried. 

• Tighten screws in doorframes and lubricate door 

hinges, awning hardware, garage door mechanisms, 

window sash chains, and pulleys using a graphite or 

silicone type lubricant. 

Contracting Maintenance and 

Repair Work 

Many contractors are very proficient in using 

modem construction methods and materials; 

however, they may not have the experience 

or skill required to carry out maintenance on 

historic buildings. The following are tips to use 

when selecting a contractor to work on your 

historic building: 

1. Become familiar with work done on 

similar historic properties in your area 

so that you can obtain names of possible 

preservation contractors. 

2. Be as specific as possible in defining the 

scope of work you expect to undertake. 

3. Ask potential contractors for multiple 

references (three to five) and visit previous 

work sites. Contact the building owner or 

manager and ask how the job proceeded; 

if the same work crew was retained from 

start to finish; if the workers were of a 

consistent skill level; whether the project 

was completed in a reasonable time; 

and whether the person would use the 

contractor again. 

4. Be familiar with the preservation context 

of the work to be undertaken. Use the 

written procedures in your maintenance 

plan to help define the scope of work in 

accordance with preservation standards 

and guidelines. Always request that the 

gentlest method possible be used. Use 

a preservation consultant if necessary to 

ensure that the work is performed in an 

appropriate manner. 

5. Request in the contract proposal a detailed 

cost estimate that clearly defines the work 

to be executed, establishes the precautions 

that will be used to protect adjoining 

materials, and lists specific qualified 

subcontractors, if any, to be used. 

6. Insure that the contractor has all necessary 

business licenses and carries worker 

compensation. 
• Check weather stripping on 

doors and windows and adjust or 

replace as necessary. Use a durable 

type of weather stripping, such 

as spring metal or high quality 

synthetic material, avoiding common 

brush and bulb or pile weather 

stripping that require more frequent 

replacement. 

• Adjust steel casement windows 

as needed for proper alignment and 

tight fit. Avoid additional weather 

stripping as this may lead to further 

misalignment, creating pathways for 

air and water infiltration. 

• Check window sills for proper 

drainage. Fill cracks in wood sills 

with a wood filler or epoxy. Follow 

manufacturer's instructions for 

preparation and installation. Do not 

cover over a wood sill with metal 

panning, as it may trap moisture and 

promote decay. 

• Repair, prime, and repaint 

windows, doors, frames, and sills 

when needed. Clean out putty debris 

and paint chips from windows using 

a wet paper towel and dispose of 

debris prior to repair or repainting. 

Take appropriate additional 

precautions when removing leadbased paint. Sand and prepare 

surfaces and use material-specific 

Figure 12. Good surface preparation is essential for long lasting paint. Scraping loose paint, 

filling nail holes and cracks, sanding, and wiping with a damp cloth prior to repainting are all 

important steps whether touching up small areas or repainting an entire feature. Always use 

a manufacturer's best quality paint. Windows and shutters may need repainting every five to 

seven years, depending on exposure and climate. 

patching compounds to fill any 

holes or areas collecting moisture 

(Fig 12). Avoid leaving exposed 

wood unpainted for any length of 

time, as light will degrade the wood surface and lead 

to premature failure of subsequent paint applications. 

Immediately prime steel sash after paint is removed and 

the substrate prepared for repainting. 

• Adjust wood sash that bind when operated. Apply 

beeswax, paraffin, or similar material to tracks or sash 

runs for ease of movement. If sash are loose, replace 

worn parting beads. Sash runs traditionally were 

unpainted between the stop and parting bead; removing 

subsequent paint applications will often help improve 

sash operation. 

• Correct perimeter cracks around windows and doors 

to prevent water and air infiltration. Use traditional 

material or modern sealants as appropriate. If fillers 

such as lead wool have been used, new wool can be 

inserted with a thin blade tool, taking care to avoid 

damage to adjacent trim. Reduce excess air infiltration 

around windows by repairing and lubricating sash locks 

so that windows close tightly. 

Figure 13. Window air conditioning units can cause damage 

to surfaces below when condensation drips in an uncontrolled 

manner. Drip extension tubes can sometimes be added to direct 

the discharge. 

11 
12 

• Remove debris beneath window air conditioning 

units and ensure that water from units does not 

drain onto sills or wall surfaces below (Fig 13). 

Removal of air conditioning units when not in 

season is recommended. 

• Adjust storm panels and clean weep holes; check 

that weep holes at the bottom of the panels are open 

so water will not be trapped on the sill. Exterior 

applied storm windows are best attached using 

screws and not tightly adhered with sealant. Use 

of sealant makes storm units difficult to remove 

for maintenance and can contribute to moisture 

entrapment if weep holes become clogged. 

• Remove weakened or loose shutters and store 

for later repair. Consider adding a zinc or painted 

metal top to shutters as a protective cap to cover the 

wood's exposed end grain. This will extend the life 

of the shutters. 

Projections 

Numerous projections may exist on a historic 

building, such as porches, dormers, skylights, 

balconies, fire escapes, and breezeways. They are 

often composed of several different materials and may 

include an independent roof. Principal maintenance 

objectives include directing moisture off these features 

and keeping weathered surfaces in good condition. 

Secondary projections may include brackets, lamps, 

hanging signs, and similar items that tend to be exposed 

to the elements. 

Inspection: 

In some cases, projections are essentially independent 

units of a building and so must be evaluated carefully 

for possible settlement, separation from the main 

body of the building, and materials deterioration. 

Some electrical features may require inspection by a 

electrician or service technician. Common conditions of 

concern to look for are: 

damaged flashing or tie-in connections of 

projecting elements; 

misaligned posts and railings; 

deteriorated finishes and materials, including 

peeling paint, cupped and warped decking, 

wood deterioration, and hazardous steps; 

evidence of termites, carpenter ants, bees, or 

animal pests (Fig 14); 

damaged lamps, unsafe electrical outlets or 

deteriorated seals around connections; 

loose marker plaques, sign, or mail boxes; and 

Figure 14. When inspecting connections between projections and the main 

building, look for areas where birds, bees and pests may enter or nest. Birds 

have been nesting in this porch roof and the area is being cleaned of their 

debris. Where an opening exists, it may be necessary to cover it with a trim 

piece, screening, or sealant. Photo: Bryan Blundell. 

rust and excessive wear of structural, anchorage, 

and safety features of balconies and fire escapes. 

Maintenance: 

• Selectively repair or replace damaged roofing units 

on porches and other projections. Ensure adequate 

drainage away from the building. Repair flashing 

connections as needed; clean and seal open joints as 

appropriate. 

• Secure any loose connections, such as on porch rails 

or fire escapes. 

• Maintain ferrous metal components by following 

manufacturer's recommendation for cleaning and 

repainting. Remove rust and corrosion from porch 

handrails, balconies, fire escapes, and other metal 

features; prepare, prime, and repaint using a corrosioninhibitive coating system. Apply new primer before 

new corrosion sets in, followed by new topcoat. Take 

appropriate safety measures when dealing with existing 

lead-based paint and in using corrosion-removal 

products (Fig 15). 

• Reattach loose brackets, lamps, or signs. With 

electrical boxes for outlets or lighting devices, ensure 

that cover plates are properly sealed. Prime and paint 

metal elements as needed. 

• Keep porch decks and steps free from dust, dirt, leaf 

debris, and snow as soon at it accumulates using a 

broom or plastic blade shovel. 

• Repair areas of wood decay or other damage to 

railings, posts, and decorative elements. Repair 

with wood dutchman, wood putty, or epoxy filler, as 

appropriate; replace individual elements as needed. 
Figure 15. Metal projecting elements on a building, such as sign armatures and railings, are easily subject to rust and decay. Proper surface 

preparation to remove rust is essential. Special metal primers and topcoats should be used. 

Prime and repaint features when necessary and repaint 

horizontal surfaces on a more frequent basis. 

• Sand and repaint porch floorboards to keep weather 

surfaces protected. The exposed ends of porch 

floorboards are especially susceptible to decay and 

may need to be treated every year or two. 

• Carefully cut out damaged or buckled porch flooring 

and replace with wood to match. Back-prime new 

wood that is being installed; treat end grain with wood 

preservative and paint primer. Ensure that new wood 

is adequately kiln or air-dried to avoid shrinkage and 

problems with paint adherence. 

• Repair rotted stair stringers; adjust grade or add 

stone pavers at stair base to keep wooden elements 

from coming into direct contact with soil. 

• Consider durable hardwoods for replacement 

material where beading, chamfering, or other 

decorative work is required in order to match existing 

features being replaced. Although appropriate for 

certain applications, pressure treated lumber is hard to 

tool and may inhibit paint adherence if not allowed to 

weather prior to coating application. 

• Clean out any debris from carpenter bees, ants, 

termites, and rodents, particularly from under porches. 

Replace damaged wood and add screening or lattice to 

discourage rodents. Consider treating above ground 

features with a borate solution to deter termites and 

wood rot and repaint exposed surfaces. 

Foundations and Perimeter Grades 

The foundation walls that penetrate into the ground, 

the piers that support raised structures, and the 

ground immediately around a foundation (known as 

grade) serve important structural functions. To help 

sustain these functions, it is important that there is 

good drainage around and away from the building. 

The maintenance goal is to prevent moisture from 

entering foundations and crawl spaces and damaging 

materials close to the grade, and to provide ventilation 

in damp areas. 

Inspection: 

Inspections at the foundation should be done in 

conjunction with the inspection of the downspouts 

to ensure that water is being discharged a sufficient 

distance from the building perimeter to avoid excessive 

dampness in basements or crawl spaces. In addition, 

crawl spaces should be adequately vented to deter 

mold and decay and should be screened or otherwise 

secured against animals. Look for: 

depressions or grade sloping toward the 

foundation; standing water after a storm; 

Figure 16. This chronically wet area has a mildew bloom brought 

on by heat generated from the air-conditioning condenser unit. The 

dampness could be caused be a clogged roof gutter, improper grading, 

or a leaking hose bibb. 

13 
14 

Sealants and Caulks 

Using sealants and caulks has become a familiar part 

of exterior maintenance today. As the use of precision 

joinery and certain traditional materials to render 

joints more weathertight has waned in recent years, 

caulks and more often elastomeric sealants are used to 

seal cracks and joints to keep out moisture and reduce 

air infiltration. Where cracks and failing joints are 

indicators of a serious problem, sealants and caulks 

may be used as a temporary measure. In some cases 

they may actually exacerbate the existing problem, 

such as by trapping moisture in adjacent masonry, and 

lead to more costly repairs. 

Manufacturer's recommendations provide instructions 

on the proper application of caulks and sealants. 

Special attention should be placed on ensuring that the 

subsurface or joint is properly prepared and cleaned. 

Backer rods may be necessary for joints or cracks. 

Tooling of the caulk or sealant is usually necessary to 

ensure contact with all edge surfaces and for a clean 

and consistent appearance. 

Caulks generally refer to older oil resin-based 

products, which have relatively limited life span and 

limited flexibility. Contemporary elastomeric sealants 

are composed of polymer synthetics. Elastomeric 

sealants are more durable than caulks and have greater 

flexibility and wider application. Caulks and sealants 

can become maintenance problems, as they tend to 

deteriorate faster than their substrates and must be 

replaced periodically as a part of cyclical maintenance 

of the structure. 

The selection criteria for caulks and sealants include 

type of substrate, adhesion properties, size and 

configuration of joint, intended appearance/color and 

paintability, movement characteristics, and service 

life. Both one-part and two-part sealants are available; 

the latter require mixing as part of the application 

process. Sealants are commonly used for a variety of 

places on the exterior of a building such as around 

windows and doors, at interfaces between masonry 

and wood, between various wood features or elements, 

and at attachments to or through walls or roofs, such 

as with lamps, signs, or exterior plumbing fixtures. 

Their effectiveness depends on numerous factors 

including proper surface preparation and application. 

Applications of sealants and caulks should be 

examined as part of routine maintenance inspection, 

irrespective of their projected life expectancy. 

Installation of caulks and sealants often can be 

undertaken by site personnel. For large and more 

complex projects, a contactor experienced in sealant 

installation may be needed. In either case, the sealant 

manufacturer should be consulted on proper sealant 

selection, preparation, and installation procedures. 

material deterioration at or near the 

foundation, including loss of mortar in 

masonry, rotting wood clapboards, or 

settlement cracks in the lower sections of wall; 

evidence of animal or pest infestation; 

vegetation growing close to the foundation, 

including trees, shrubs and planting beds; 

evidence of moisture damage from lawn and 

garden in-ground sprinkler systems; 

evidence of moss or mold from damp 

conditions or poorly situated downspout 

splash blocks (Fig 16); and 

blocked downspout drainage boots or clogged 

areaway grates. 

Maintenance: 

• Remove leaves and other debris from drains 

to prevent accumulation. Detach drain grates 

from paved areas and extract clogged debris. 

Flush with a hose to ensure that there is no 

blockage. Use a professional drain service to clear 

obstructions if necessary. 

• Conduct annual termite inspections. Promptly 

address termite and other insect infestations. Use 

only licensed company for treatment where needed. 

• Keep the grade around the foundation sloping 

away from the building. Add soil to fill depressions 

particularly around downspouts and splash 

blocks. Make sure that soil does not come too close 

to wooden or metal elements. A 6" separation 

between wooden siding and the grade is usually 

recommended. 

• Avoid use of mulching material immediately 

around foundations as such material may promote 

termite infestation, retain moisture or change existing 

grade slope. 

• Reset splash blocks at the end of downspouts or 

add extender tubes to the end of downspouts as 

necessary (Fig 17). 

• Lubricate operable foundation vent grilles to 

facilitate seasonal use; paint as needed. 

• Manage vegetation around foundations to allow 

sufficient air movement for wall surfaces to dry 

out during damp periods. Trim plantings and 

remove weeds and climbing vine roots. Be careful 

not to scar foundations or porch piers with grass or 

weed cutting equipment. If tree roots appear to be 

damaging a foundation wall, consult an engineer as 

well as a tree company. 
• Wash off discoloration on foundations caused by 

splash-back, algae, or mildew. Use plain water and a 

soft natural or nylon bristle brush. Unless thoroughly 

researched and tested beforehand on a discreet area 

of the wall, avoid chemical products that may discolor 

certain types of stone. If cleaning products are used, 

test beforehand in a discreet area; and avoid over 

splash to plantings and adjacent building materials. 

• Selectively repoint unit masonry as needed. Follow 

guidance under the wall section in regard to compatible 

mix, appearance, and texture for pointing mortar. 

• Avoid using salts for de-icing and fertilizers with a 

high acid or petro-chemical content around foundations, 

as these materials can cause salt contamination of 

masonry. Use sand or organic materials without 

chloride additives that can damage masonry. Where salt 

is used on icy walks, distribute it sparingly and sweep 

up residual salt after walks have dried. 

• Use snow shovels and brooms to clean snow from 

historic paths and walkways. Avoid blade-type snow 

removers as they may chip or abrade cobblestones, brick, 

or stone paving. Note that use of steel snow removal 

tools in areas where salt-containing snow melters are 

used may result in rust staining from steel fragments left 

on the paving. 

Conclusion 

Maintenance is the most important preservation 

treatment for extending the life of a historic property. 

It is also the most cost effective. Understanding the 

construction techniques of the original builders and 

the performance qualities of older building materials, 

using traditional maintenance and repair methods, and 

selecting in-kind materials where replacements are 

needed will help preserve the building and its historic 

character. 

Maintenance can be managed in small distinct 

components, coordinated with other work, and 

scheduled over many years to ensure that materials are 

properly cared for and their life span maximized. A 

written maintenance plan is the most effective way to 

organize, schedule, and guide the work necessary to 

properly care for a historic building. The maintenance 

plan should include a description of the materials and 

methods required for each task, as well as a schedule 

for work required for maintenance of different building 

materials and components. 

Historic house journals, maintenance guides for older 

buildings, preservation consultants, and preservation 

maintenance firms can assist with writing appropriate 

procedures for specific properties. Priorities should be 

established for intervening when unexpected damage 

occurs such as from broken water pipes or high winds. 

Figure 17. Extending downspouts at their base is one of the basic 

steps to reduce dampness in basements, crawl spaces and around 

foundations. Extensions should be buried, if possible, for aesthetics, 

ease of lawn care, and to avoid creating a tripping hazard. 

Photo: NPS files. 

Worker safety should always be paramount. When 

work is beyond the capabilities of in-house personnel 

and must be contracted, special efforts should be 

made to ensure that a contractor is both experienced 

in working with historic buildings and utilizes 

appropriate preservation treatments. 

A well-maintained property is a more valuable 

property and one that will survive as a legacy for 

generations to come. 

Endnotes 

1. The Secretary of the Interior's Standards for the 

Treatment of Historic Properties. Washington, D.C.: U.S. 

Department of the Interior, National Park Service, 1995. 

2. Committee on Advanced Maintenance Concepts 

for Buildings et al, Committing to the Cost of Ownership: 

Maintenance and Repair of Public Buildings, Washington, 

D.C.: National Academy Press, 1990. 

15 
16 

Further Reading 

Chambers, J. Henry. Cyclical Maintenance for Historic 

Buildings. Washington, D.C: National Park Service, 1976, 

Fisher, Charles E. and Hugh C Miller, eds. Caring For 

Your Historic House. New York, NY: Harry N. Abrams, 

Inc., 1998. 

Fisher, Charles E., Deborah Slaton, and Rebecca Shiffer, 

eds. Window Rehabilitation Guide for Historic Buildings. 

Washington, D.C: Historic Preservation Education 

Foundation, 1997. 

Fram, Mark. Well-Preserved: The Ontario Heritage 

Foundation's Manual of Principles and Practice for 

Architectural Conservation. Erin, Ontario: The Boston 

Mills Press, 1988. 

Gayle, Margot, David W. Look, AlA, and John G. Waite, 

FAIA. Metals in America's Historic Buildings: Use and 

Preservation Treatments. Washington, D.C: National Park 

Service, 1992. . 

Grimmer, Anne E. Keeping It Clean: Removing Exterior 

Dirt, Paint, Stains & Graffiti from Historic Masonry 

Buildings. Washington, D.C: National Park Service, 1988. 

Acknowledgements 

Jester, Thomas C, ed. Twentieth Century Building 

Materials: History and Conservation. New York, NY: 

McGraw-Hill,1995. 

Leeke, John C Practical Restoration Reports Compendium. 

Portland, ME: Historic HomeWorks, 2005. 

London, Mark. Masonry: How to Care for Old and Historic 

Brick and Stone. Washington, D.C: The Preservation 

Press, 1988. 

Preservation Briefs. Washington, D.C: National Park 

Service. The collection of Preservation Briefs assist 

owners and developers of historic buildings in 

recognizing and resolving common preservation, 

maintenance and repair problems. 

Preservation Tech Notes. Washington, D.C: National 

Park Service. The collection of Preservation Tech Notes 

provides guidance and case studies on the care and 

maintenance of historic structures. 

Yapp, Bob and Rich Binsacca. About Your House with Bob 

Yapp. San Francisco, CA: KQED Books & Tapes, 1997. 

Sharon C Park FAIA, is the former Chief of Technical Preservation Services, Heritage Preservation Services, National 

Park Service, in Washington, D.C and currently is the Associate Director for Architectural History and Historic 

Preservation, Smithsonian Institution. 

The author wishes to thank Mike Seibert of the National Park Service for research on the project and the development of 

the charts; and Lauren Burge, AlA, of the firm of Chambers, Murphy & Burge, and Michael Emerick, AlA, for sharing 

their expertise on maintenance and providing early guidance. Thanks go to Deborah Slaton of the firm of Wiss, Janney, 

Elstner Associates, Inc., for her insightful contributions and also to Rebecca Stevens of the National Park Service, 

Dominque Hawkins, AlA, of Preservation Design Partnership, J. Bryan Blundell of Dell Corporation, and Michael 

Scheffler and Kenneth Itle of Wiss, Janney, Elstner Associates, Inc. Also gratefully acknowledge for their assistance in the 

technical review and editing of this publication are Charles E. Fisher, Anne E. Grimmer, and Chad Randl of the National 

Park Service's Technical Preservation Services, and former staff Kay D. Weeks. Numerous other National Park Service 

staff and partners commented on the manuscript and made substantial contributions. 

This publication has been prepared pursuant to the National Historic Preservation Act, as amended, which directs the 

Secretary of the Interior to develop and make available information concerning historic properties. Comments about 

this publication should be made to: Charles Fisher, Technical Publications Program Manager, Technical Preservation 

Services-2255, National Park Service, 1849 C Street, NW, Washington, D.C 20240. Additional information offered by 

Technical Preservation Services is available on our website at <www.nps.gov/history/hps/tps>.This publication is not 

copyrighted and can be reproduced without penalty. Normal procedures for credit to the author and the National Park 

Service are appreciated. Unless otherwise noted, photographs in this Brief are by Sharon C Park, FAIA. Except for 

the author's photos, the photographs used in this publication may not be used to illustrate other publications without 

permission of the owner. 

ISSN: 978-0-16-078974-8 

U.S. Government Printing Office Stock Number: 024-005-01252-4 June 2007