Untrue Beliefs About Wood

l. Wood Schools ore dongerous becquse.of fire hqzqrd. In properly built schools, the materials of construction have no influence on the fire hazard to life of the occupants. The only really fire-safe school is the one-story school with an exterior exit in every room-and it is completely safe regardless of the materials used in building. Exert your influence to have such schools built in your district.

2. Steel is stronger thqn wood.

Weight for weight, many woods are stronger than steel.

3. Sopwood is stronger thqn heqrtwood or vice verso.

Under dry conditione of use one is as strong as the olher' For ' instance, for years ilie trade tlought hickoiy hihilles of white sapwood were stronger'than those made of brownish heart' wood. Many tests proved this is not so.

4. Airrdried. lumber is slronger thqn kiln dried or vice versq. When properly dried to a given :noisture content one is as strong as the other.

5. Wood from live trees is stronger lhon wood from deod lrees-qs for inslqnce, trees thot hove died from q foresl fire or olher tquses.

Sound wood or unburned wood from dead trees or trees that have been in a forest fire is just as strong 'as wood from live trees.

6. Wood from lurpentined pine lrees is weoker lhon wood from unturpenlined lrees.

There is no rribasurable difference in the strengths.

7. Thqt plywood t'slronger thqn wood in oll respects.

Assuming the sdme grade of the same species, a piece of fiveply plywood with'each ply I/" thick in a panel 12" wide by 4'long supported under pach end will carry a load only about two-thirds as heavy as will be carried by a piece of solid lumber of the same dimensions. Other assemblies of plywood will likewise be weaker than equal sizes of solid lumber' In some other respects plywood is stronger. For instance, plywood is stronger across the width than is lumber.

8. Todoy's lumber is nol os good os thqt of yeors qgo.

Grade for grade, the lumber of today is at least as good as ever before and probably better because of improved seasoning and machining methods.

9. Wood will "dry rol."

There is no such thing as "dry rot" and we should all stop using that term. The wood may be dry and rotten when in' spected, but when the decay occured the moisture content of the wood was above 20/o. When wood is used where it will remain dry; that is, below 20/o, no wood will decay-not even the sapwood of anY wood.

lO. High lemperqtures with high humidities will cquse wood lo decoy.

This is not true. Even if we kept wood for years in a temperature of 100 degrees Fahrenheit with a relative humidity of 90/o, the wood will not decay. There is no place in the U. S. A. where the temperatures and the humidities are such that they will cause wood to reach a moisture content that will permit wood to decay. For wood to decay in this country, it is necessary that it be in or on the ground exposed to liquid water that will remain on it long enough to wet the wood for an extended period of time. The easy way to prevent decay is to use well-known good construction methods,so that no water pochets ar€ present. Where special construction resuhs in recesses or places where water can gather and remain, use the heartwood of a naturally durable wood or preservedly treated for long life.

I l. Time will couse wood lo decoy.

This is not so. I{ wood is kept at a moisture content below 20/o, it will never decay-and that means never.

12. Thqf the mere choice of q nslurolly duroble species of wood will prevent decoy under wei conditions.

It is necessary to use the heartwood of the naturally durable species to get protection against decay under wet conditions. Directly underneath the bark of a tree is the new wood that grew there just recently. In most woods it is sort of white in color and is called sapwood. The sapwood of any wood decays very easily if it stays wet. Underneath the sapwood is the older wood that grew years ago. In most woods is is dark brown or dark red and is called the heartwood. It is this heartwood that is naturally durable in some species. Properly treated wood also resists decay,

13. Some woods qre nqlurolly immune lo termile ottock.

Any wood placed in the ground in termite.infested areas must be properly treated to protect it against termites. This is easily done. Houses using any kind of wood are easily protected against termite attack by well-known proper construction methods.

14. Some woods end shrink more lhon others.

The normal wood of all species has about the same low end shrinkage. The generel range of wood moisture content from the driest to the wettest seasons of the year in most parts of the nation is about Saft. With this range of moisture content a sixteen-foot piece of normal lumber hanging free in the air will end-shrink alnut 1/16 inch. When nailed tight, as is done with siding, trim, etc., this shrink.rge is reduced to less than l/64", Shorter pieces will shrink even less. An abnormal piece with compression wood in it will shrink more. Compression wood should not be put into housing items like siding, etc. (Conthwed, on Page 27)

Weldwood Hearthside'" Paneling

-six superior wood-grain reproductions on hardboard

It's thc firicst qrralitr' line of clecorativc harclboarcls yorr vc cvcl' sc('n u'itlr sharp, rich reprocirrctions of u'<locl grains on lleartlisiclc l'aneling. And likc tlrc crrtr'r'c: \\rcl clu'o<lc[ "' I{irrclbotrrcl line-stan cliu'cl, tcnrpt'rcrl, ltcrforatc'cl, ancl spccialtv hirrclboarcls-it u'ill lru cirsir:r Io st:ll at full margin. Bccrurse it ciu-r'ics thc naurc \\'clcls'oocl-tlie most u,idclv acllcltisccl uncl ac,c,r,ptcrl nirrnc in paneling. Be srrrc to ask r orrr Lrrritt.rl Strrtt's Plvu'ood rt'lilesentrLtivt' rrlrorrt it.

Weldwood Hardboards

Statesptywood

vttELE,rrrooEt'