ffIACHIN ERY

New'Fireproofed'Wood Building Gan Compete Wirh 'Substitutes'

A new standard of industrial construction. the Cross, Austin "Fireproofed" Wood Building,-was unveiled to the building trades. The unique wood-and-aluminum structure, use of which was made possible by recent New York City building code revisions, is expected to be fully competitive with conventional buildings for such uses as factories, warehouses, garages and bowling alleys.

Col. J. Bryan Williams, president of Cross, Austin & Ireland Lumber Co., Brooklyn, N.Y., indicated a significant impact of the code revision would come in single-story industrial and commercial construction. The fireproofed building erected by his company is in this category. It features a structural framework of pressure-impregnated wood and an aluminum exterior.

Since the New York City building code has long been accepted throughout the United States and abroad as a pace-setter, Col. Williams said that it was likely the trend toward fire-retardant structural wood construction would increase.

The revised code permits use of such fireproofed wood for structural members in Class 5 buildings, which are one-story structures with a maximum of 15,000 square feet of floor space.

The Cross, Austin warehouse has the maximum floor space. It will be used to store up to one million board feet of finished and kiln-dried lumber.

Significantly, no structural steel was employed in its construction. Carpenters assembled the fireproofed Douglas fir bays and trusses on the site and also sheathed the framework.

An advantage of the fireproof weod construction is that practically no maintenance is required. This was a major factor in the choice of the aluminum exterior.

The new building is cheaper than conventional buildings, Col. Williams said, and its insurance rate is lower. On the new warehouse the insurance rate will be $1.05 oer $1000 compared

Struclurol frmewqk ulilized limberr pFlru.e-lreoled fq nre re3l5ttre qd held togefher by boltr od splitrlng timber coile.l*. Es.h of the 12 boyr wm loid oul od qs:mbled d growd, tho rqired fo form struclurol mmbers of rhe build. ing; l3 trur* were olro csmbled on the gromd

Cmpleled building, ured for wqrGhoering, hc l5,OOO rq. tt. of eoor rpoce ond rlore! up to | ,OOO.OOO boord feel of ini:hed ond kiln-dried lumber.

Itodel of fireproofed wod <hurch rhows how fmes qre relfli.ted lo moleriols within; model built with unfreqted wood de5 nol (ontoin fire (rightl od toon collopses. Both model! were stuffed wirh similor mounts of excelsior ond lighted ql sme time with $1.15 per $1000 of insurance for a building on the same site using slructural steel. This represents a saving of nearly t0%.

The tte* warehouse was built for approximately 10 to 15 cents per square-foot less than con.rparable steel coustruction, according to Col. Williams.

A further advantage of fireproofed structural timbers over those of steel is that the wood retains its strengtl-r under fire cor.rditions. In burning buildings this often means temperatures of more than 1300oF. Steel usually begins to lose significant strength at temperatures less than 1000oF., Col. Willian-rs said' While treated wood will char at these temperatures, he pointed out, it retains nearly all of its strel-rgth.

The entire wood structure was precut to final or near final size, incised to assure deep per.retration of the fire-retardant solution, then pressure treated by the vacuum pressure process using such pressures and temperatures necessary to assure a thorough trbatment. The stock was allowed to season after treatment and before fabrication and assembly.

Each truss ancl wall section was assembled with bolts and ring connectors on the ground ar.rd then hoisted into place by crane.

After tl-re entire skeletal structure was in place, the roofing and siding were applied directly to the "fireproofed" wood nailers. beams and Dosts by the same carpenters who assembled the "fiieproofed" wood structure.

Some classic examples of "fireproofed" wood structures were found during World War II when the Navy built many "lighter-than-air" hangars. These buildings were all fire-retardant pressure treated wood, approximately 300 feet wide, 1,000 feet long and 170 feet high. Each hangar used about 150 carloads of lumber. Their fire record is most outstanding in that where conflagrations occurred, only minor structural damage resulted. Content fires were contained and affected areas remained at a minimum since the treated stock did not support combustion. Repair of damage was small.

To sum up, this fireproofed wood and aluminum building has the following qualities:

1. Structurally the equal of metal buildings.

2. Economical to build.

3. Will not support combustion.

4. Easy to erect.

5. Structural members will not tend to distort or collaose like metal under fire exposure.

6. Practically maintenance-free.

7. Recognized by insurance carriers for a reduced rate.

8. Very flexible as to design or usage.

9. May be completely erected by carpenters.

10. Gives security against fire at low cost.

-by Henry Vettel, Technical Director, Cross, Austin & Ireland Lumber Co.

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