Hardwood paneling and mobile homes

by Wllliam J. Groah, technical director Hardwood Plywood Manufacturers Assn.

wall paneling was lauan and other tropical hardwoods mostly supplied by Asian and Pacific countries.

Story at a Glance

This article was originally part of a speech presented by Wm. Groah to the successful Third Asian Plywood Conference, held recently in Seoul, Korea . . paneling's changing role from decorative to structural in mobile homes as well as the Droblems of new reoulations and their effects on -products and sales, are described.

rTr HERE are two important factors r in understandingthe wall paneling market in the United States. The first is the change in the ratio of types of housing units now being built. The second is the nature ofthe regulations that control the manufacturer of these housing units.

The largest volume ofwall paneling is used in single family on-site constructed homes and in mobile homes.

A third important market for wall panels is the remodeling market which includes improving and expanding older housing units. It has been estimated that $18 billion dollars was spent in remodeling in 1971. This amount includes multi-family homes as well as single family homes.

A survey by the Hardwood Plywood Manufacturers Assn. indicates that 5.3 billion sq. ft. (500 million sq. meters) surface measure of prefinished wall panels were shipped to United States markets in L972. Approximately 807o of this

While the mobile home market by total dollar volume is smaller than on-site constructed homes and remodeling, it is very important for the hardwood plywood wall paneling manufacturer. A number of studies have shown that the average mobile home utilizes about 2,000 sq. ft. (185 sq. meters) surface measure of wall paneling. In I97 2, approximately 1.2 billion sq. ft. (ltl million sq. meters) of plywood was used in mobile homes.

Hardwood plywood is the primary interior wall material in these homes because it is light in weight and does not crack or split when subjected to over the road transport.

Hardwood plywood is important in resisting wind loads perpendicular to the.length of the mobile home. Since the length of these homes are typically five or more times longer than the width, the short transverse end walls and the interior partition walls can be subject to fairly severe wind loads. Hardwood plywood wall paneling has an important role in resisting these wind loads.

In order that a mobile home be structurally satisfactory, the designer has to have proper engineering data which describes the mechanical property values of various building materials used.

Plywood is cross laminated and the mechanical properties parallel to the wood grain direction of the surface are different from the mechanical properties perpendicular to the wood grain direction of the surface.

In order to provide the State of California with the engineering data that they require, the Hardwood Plywood Manufacturers Assn. has sponsored several series of large

.gcale rackingtests. In addition, cer: tain theoretical section property values have been computed for 3.6mm, 4.Omm, 4.4mm,4.9mm, and 5.Smm thick plywood panels. These section property values are'used by mobile home engineering designers in securing design approval from the state.

The section property values depend on certain physical features of the panel. Features such as the thickness ofthe face, back, and core veneers are very important. In addition, the density of the wood species; the overall thickness of the panel; the number, typ€, and location of open defects; and the depth and number ofsurfacb v-grooves all have to be known in order to compute the structural section property valu'es.

Engineering data developed for various thicknesses of hardwood plywood was supplied to the State of California in 1971. These values are now being revised to more realistically describe the products being made today. So that the engineering values to be used in the future by the mobile home designers in the State of California have meaning, the panel features as outlined above have to be described. Wall panels used in mobile homes must conform to the panel features as described.

Because of the complexity of the mobile home construction standard, when we speak of the requirements of a single stateo it is important to realize that the impact is not confined to a single state, but many states. Mobile homes sold in California can be shipped from almost any western state. Mobile homes produced in California can be shipped over the western part ofthe United States. In addition. with each passing month, there is a tendency for other states to more strictly enforce mobile home construction standards.

There have been changing patterns of home construction in recent years resulting in the mobile home becoming an important part of the single family housing mix in the United States. Thin hardwood plywood wall panels, which until a few years ago, were considered only decora- j tive interior wall covering, are now structural products.

There has also been increased I emphasis on standards, safety, and I consumer protection during the past I few years.

Energy Conservation

Two booklets relating to industrial energy conservation measures are from the U.S. Government Printins Office. Prepared by the Office of Energy Programs, U.S. Department of Commerce, the bookf ets are entitled. " How to Start an Etrcrgy Management Program" and "33 Money-Saving ll/uys ta Conserve Energy inYour Business." Theycan be purchased from the Superintendent of Documents, U. S. Government Printing Office, Washington, D.C. 20402, 25c each.

Roof Disc Stapler

An illustrated 4-p. brochure that describes the work-saving t'eatures of the Disc-A-Matic roof disc stapler is being offered by Bostitch. The Stapler. is best used on roofs of most large commercial buildings to attach base sheet to a nailholding deck.

Maintenance Platform

A nerv 6-p. illustrated application and operations brochure is norv available free on Economv Engineerinu's new maintenance p[atforln called the Uppup. Detailed photographs shorv it in vaflous uses.

Timber Supply

The complex facets on the problem of timber supply and holv it can be solved are outlined in a nerv free booklet. "fhc Timber Supply Issue," by the National Forest Products Assn. Write NFPA, 1619 Massachusetts Ave., N.W., Washington, D.C. 20036.

Weatherstrip Guide

The first guidebook (20.p) prepared specifically for industralized builders on weatherstrip and thresholds is available free. lt shows horv to cut costs while selecting the best performing weatherstrip and thresholds and solve problems of industrialized building, such as coping with doorway gaps opened as the structures or components are moved. lt furlher describes current product and technical development.

Free Reader Service

For furiher informotion on oll New Producls ond New Litero ture, write fhe Merchont Magozine, 523 So. Loke Ave., Posodeno, Co. 91 I0l. Pleose mention issue dote ond poge number so we con process your request foster! Thonks.

A Tough Sign

Available free is a full-color brochure describing abuse, chemical and fadeproof signs. SG L Graphics offers 10 colorful examples of Modulate (rigid) and Moducal (flexible) signs in practical applications. A representative list of companies using SC L Graphics' signs is included.

Flush Doors Described

Prefinished doors for commercial. institutional and residential construction are fully described in a new 8-p. fourcolor brochure from Simpson Timber Co. lllustrations and information on the Colutnbia, a prefinished hardrvood door; Lr,qnr'l', a prefinished hardboard door; and Lifeclud, a high pressure laminate door, are presented along with bi-fold units and unfinished flush cloors.

Superman? No, Palletman!

Updated and expanded literature on Pulletmutt power lift stackers (AllisChalmers) describes eight models ranging in lift heights from'74" to 150". Details covered include overall heisht. rvidth. straddle dimensions and lencth overall.

Lawn, Garden Sprinklers

A 28-p. full color free catalog from Melnor Industries. features "Sell-onSight" packaging on l2 best selling items.

Pick From 1,650 Tools

GoldblattTool Co. has just published its 1974 Tool Catalog listing over 1,650 quality tools. This 72-p. free color catalog contains complete descriptions and illustrations of all tools needed by cement, drywall. plastering and masonry tradesmen. It also lists many specialty tools for tradesmen in related fields.

Shingle Panels For Interiors

The rustic beauty and application ease of Western Red Cediir Shinsles in panels for irpplication to interior riirll: is shown in a new free brochure on Interior-Tex panels.

Two Research Reports

The following reports have been published by the Forest Products Research Soc iety and are available at 50c per copy from the FPRS, Dept.2,280l Marshall Ct.. Madison, WI 53705. (Payment should accompany request.)

(1) "A Murketittg Infounution Systenr For The Woocl Products Manufocturer" is a system based on values of relative marketing efficiency and price variances designed to help the wood products manager arrive at a more efficient allocation of marketine activitv.

\2) "Itnprot'ing Tlte Surfuc'e Quality Of Ripsart'tr Dry Ltunber" shorvs that surface quality can be improved when the teeth of circular saws cut as close as possible to the direction of the grain. This method also produces residues more suitable for pulping. Useful data on power requirements and sarvn surface quality are provided.

Wood Windows & Energy

In a new, fully-insulated house, it is a fact that wood windows with insulatins glass can save an additional 3V7t of th! remaining heat loss and reduce the homeowner's fuel cost by an equal amount. This statement is fullv explained with facts and figures in a free booklet by Ponderosa Pine Woodwork, an association of leading woodwork manufacturers and lumber suppliers.

Death & Disability

" W lren Qtrulitt ttnd Stabilitv Cctuttt," distlibuted free by the Kemper Insurance Group, graphically illustrates how the chances ofbeins disabled far exceed the chances ofdea[h in every age category. Write Kemper Insurance, Long Grove, Ill. 60049.

.Dock Accessories

Updated and consolidated literature covering its lines ofdock accessories is from Allis-Chalmers. Described and illustrated are stabilizing jacks, truck rvheel chocks, rail chocks, dock lights and dock bumpers.

Lock-Deck Decking

Full-color free brochure illustrates ways Potlatch's Lock-Deck decking makes possible many structural and design concepts beyond the commonplace. Uses pictured are for residences, school, condominiums and recreation center.

Remodeling Door System

Product literature is available on the nerv Sta-Tru "R" remodeling door system from Stanley Door Systems. It contains product information, available sizes, required opening dimensions, and how to determine the size door required.

Title Installation Handbook

The Title Council of America, Inc. has published a new and extensively revised 1974 Handbook for Ceramic Tile lnstallation. The free annual handbook provides quick reference details and a means for simplifying and standardizing installation specifications for ceramic tile. Single copies are free from the Tile Council of America, Inc., P.O. Box 326. Princeton. N.J. 08540.