The Birmingham age-herald., 1921-04-03
HOLLOW BUILDING
 TILE PROVES VALUE
Strength, Beauty, Deprecia- ton and Cost Must All Be
 Considered
By CARL F. BAER General Manager

Ine most remdrkaDle 1act m cOnnec- tion with hollow tile is it's tardy recog- hilton by the building public as a de- sirable and economical material for resi- dence construction.
 Many acres of office building floors and thousands upon thousands of parti- tions testify to it's value for fire proofing purposes, yet less than 10 years ago all hollow tile structures built in the Birmingham district could be counted upon both hands, but the many merits of this material soon came to be known, as the many fireproof office buildings, factories, store buildings and residences built of hollow tile will show.
 Until several years ago hollow tile was not used as finished product. but had to be rather covered with a stucco fin- ish or veneered with brick. It was not thought that hollow tile could be im- proved very much, but still that very thing was done by the Roper-Strauss- Ferst Tile company, which manufactures hollow tile in large quantities at North Birmingham, when they put on the mar ket their Ruff Texture Face Tile. !" This material has the appearance of a high-class texture brick and comes in a full range of colors. This material took from the very start with the result that at the present time some of the most beautiful buildings and residences in Birmingham are built of this material.
 The advantages of hollow tile walls are many and a few of the most important features are set forth herewith:
 STRENGTHEN strength of any wall is chiefly dependent upon two factors: First, the material or units of which it Is built, and second, the method of joining or building the material or unit in place.
 In hollow tile construction the first item Is the tile, and in these units we have a material which has an ample surplus of strength for all ordinary re- quirements greater than any cementing bond of mortar that may be used in it's erection. The strength of any wall built of this material is therefore, as with most forms of construction, de- pendent on the second factor or cement ing medium.
 With all forms of hollow building tile construction only a cement mortar should be used, and the amount of mor- tar required is comparatively so small that there is little reason for using any thing other than a good, rich mixture. wall of hollow tile properly laid in good cement and lime mortar will de- velop about 60 to 75 per cent of the strength of the tile and this assures very strong wall.
 DEPRECIATION = Closely connected with the question of strength is the question of depreciation of the material itself. The cementing medium must also be considered.
 In hollow tile construction there is ab- solutely no depreciation of the material itself. Hard burned clay has stood through the ages and will continue to do so as long as man himself is on earth. The cementing medium is also equally as permanent. This material was used by the Romans and is responsible for the wonder permanence of their great masonry structures.
 INSULATING vALUE-Heat and cold may penetrate the wall of building Tn two ways: First, by conduction through the solid material of which the wall is built and second, by leakage.
 There can he no appreciabie leakage through any dense masonry material, and the hard-burned clay of which hollow tile is made is an effective bar to any such leakage Conduction is the only way by which heat or cold may be trans ferred through a wall of hollow tile. Air, particularly dead air. is the poorest conductor of heat, and for this reason it is utilized for the purpose of insula- tion in hollow tile construction. Ar cells are built into the wall in such a manner that any conduction Of coid through the solid material is absorbed and neutralized within the wall. itselI. Therefore home built of hollow tile IS always cooler in summer and warmer m winter.
 DRYNESs- Condensation or sweal is q condition that is common to all walls under certain conditions and may occur with any form of wall construction. Con- densation will naturally occur to much greater extent with walls that have a low insulation value, and a wall of hoi- low tile is therefore less liable to tnis condition than most other forms of con struction.
 The first cause of damp walls, that of absorption. does not require considera- tion in so far as the tile is concerned, as this product is burned to a density that renders the absorption too low 10 eanse trouble even under the most se- vere weather conditions. Hollow tile IS essentially a dry wall and therefore pro notes health. In order that no partltioh of dAmp-resisting propertie sof the hoi- low tile wall may be lost, the cement mortar that is used in laying the tie should be dense mixture, and for that as well as other reasons, it IS custo- mary to add about 15 per cent Of the ny drated lime to the cement
 FIRE RESISTIVE WALLS-To be fire resistive wall must first be built of noncom bustible material; second, it must withstand heat without cracking, disin- tegrating or losing strength. A wall built of hard-burned clay cannot be burned or destroyed by fire. Further more, being nonconductive wall, 1t will protect inflammable material on the opposite side from ignition or damage. It is a dependable fire wall material.
 PERMANENCE-The is no mainte- nance expense connected with hollow tile wall. It is built to stay Tor all time, and when the last tile has been laid conn pleting the wall, there is no ,expense whatever in the way of maintenance ana repairs.
 ECONoMY-Probably the easiest and best way to show the cost or nome built of hollow tile is to compare il with one built of lumber mus taNls hollow tile construction, which statistics show to cost from to per cent ose. frame. and using the higher percentage excess of 2 per cent, suppose we figure out the result. As frame house costing s10.00o would at per cent cost in hollow tie s1o,70O, everything being the same except the walls. Does the initial ex- cess cost of $7oo really mean that the tile house is more expensive than frame Time must give the answer, as time IS one of the chief considerations in build ing house.
 Suppose then we take these two houses and estimate their respective values at the end of 10 years, the usual period for having off the mortgage! The expenses in carving a house from year to year