# Presentation: 544289

## Practical Responses to Above Grade Moisture Problems

- Presented by
- Marilou Cheple
- Cold Climate Housing Program
- University of Minnesota
- Curriculum by
- Cold Climate Housing Program
- The Builders Association of Minnesota
- The Builders Association of the Twin Cities

## Practical Responses to Above Grade Moisture Problems

- Drainage Planes
- Windows and Doors (Fenestration)
- Other Penetrations
- Roof/Wall Connections
- Deck Ledges
- Rim Joists

## Drainage Planes	

- What happens if we don’t have a drainage plane
- Bulk water penetrates the exterior finish
- Wets sheathing materials
- Enters framing cavity through holes
- Deterioration of sheathing materials or cladding
- Structural deterioration
- Mold damage
- Wetting of insulation

## Drainage Planes

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## No Drainage Plane

- No Drainage Plane

## No Drainage Plane

** ****Gaps = holes**

## No Drainage Plane Continuity

- Wind driven rain can enter through soffits and run behind drainage plane

- No Drainage Plane Continuity

## Drainage Planes

- Proper installation
- Complete coverage
- Continuity through deck ledgers, porch/roof connections and trim details
- Proper layering and flashing
- Over flashing at roof/wall connection
- Over head flashing at windows and doors
- Over deck ledger flashing
- Extended under soffits
- Sealed penetrations

## Fenestration

- Windows
- Doors
- We build perfectly good walls and then put holes in them

## Fenestration Failures

- What happens
- Bulk water movement
- usually from the outside
- especially at head and mulls
- Capillarity
- between adjacent materials examples with small enough gap
- Vapor movement
- air flow and diffusion
- moves in either direction

## Fenestration Failures

- Moisture intrusion damage
- mold growth in wall cavities
- deterioration of structural members
- reduced insulation effectiveness
- deterioration of drywall
- wetting of other interior materials

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## Moisture Failure Modes

- Corner leaks
- Leaks between mulled units
- Leaks at head flashing
- Leaks between window unit and exterior finishes
- especially at the bottom; but sides, as well
- Flange/fin leaks
- Window unit leakage

## No weather-resistive barrier

**No weather-resistive barrier**
**Rough opening isn’t flashed**
**No protection at weakest point**
**Multiple failure w/ torn sheathing**

## Integrate flashing with weather-resistive barrier

**Corners are vulnerable**
**Need correct pan flashing to protect**

## No Head Flashing

**No building paper, can’t integrate flashing**

## Correct Integration of House Wrap with Header

**Correct integration of house wrap with flashing on rough opening**
**Head of nailing fn is put UNDER house wrap**
**Corners are taped**
**Other flashing is put on shingle fashion**

## Other Penetrations

- Penetrations
- Electrical
- Venting
- Plumbing
- Other

## Other Penetrations

- Damage – same as windows
- Flash like windows
- All materials shingle fashion
- Seal paths into cladding

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## Slide 22

## Correct flashing details for pipe & vent sleeves

- Courtesy of Minnesota Lath and Plaster Bureau

## Deck Ledgers

- What happens
- Bulk water entry
- Air movement
- The damage
- Structural deterioration
- Wall insulation damage
- Surface mold growth

## Deck Ledgers

- The cause
- Lack of or poor flashing
- Unprotected penetrations
- Poor weather barrier integration

## Flashing Details for Deck Ledger

- Courtesy of APA Engineered Wood Association

## Deck flashing details

- Does this help?

## Roof/Wall Connections

- What happens
- Bulk water entry
- Air movement
- The damage
- Structural deterioration
- Reduced energy efficiency of insulation
- Mold growth on structural members
- Deterioration of wallboard and finish materials

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## Roof/Wall Connections

- Proper installation
- At wall/roof connection
- Proper layering and flashing
- Run roofing paper up the wall
- Place step flashing woven into shingles
- Bring drainage plane over flashing
- For roof extensions
- Place drainage layer on wall before framing
- Tuck drainage plane under the tab at the soffit

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## Rim Joists

- What happens
- Diffusion
- from house
- from foundation
- Air movement
- Capillary action from the foundation
- Bulk water entry

## Rim Joists

- The damage
- Structural deterioration
- Surface mold
- Possible indoor air quality problems
- Reduced insulation effectiveness
- The cause
- Lack of or poorly installed insulation
- No air barrier or poorly installed air barrier
- Lack of vapor retarder
- Leaky supply ductwork in floor cavities

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## Slide 39

## Rim Joists

- Proper installation
- Air barrier and vapor retarder must be included
- Install adequate insulation
- Insulation on the exterior is recommended
- Extra care must be taken at deck ledgers

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