Vinyl Siding Standards · Table 1: Selected ASTM Standards Referenced by ASTM D 3679 and D 4477 D 618 Practice for Conditioning Plastics for Testing D 635 Test Method for Rate of

Vinyl Siding

StandardsBuild Consumer Confidence

inyl siding has long beenthe most popular exteriorcladding choice for NorthAmerican homes1 because

of its versatility, attractiveness, low-maintenance durability, and value.The performance and consistency ofNorth American vinyl siding hasbeen enhanced by an array of ASTMstandards under the jurisdiction ofCommittee D20 on Plastics, Sub-committee D20.24 on Plastic Build-ing Products.

ESSENTIAL PRODUCTQUALITY ANDPERFORMANCEThe flagship ASTM International

standards for vinyl siding are D 3679,Specification for Rigid Poly(VinylChloride) (PVC) Siding, and D 4477,Specification for Rigid (Unplasti-cized) Poly(Vinyl Chloride) (PVC)Soffit. These two documents refer-ence, in turn, a number of otherstandards for specific properties orperformance criteria. Some of thosestandards are shown in Table 1.

The Vinyl Siding Institute usesthose standards as the benchmarksfor its VSI Vinyl Siding Product Cer-tification Program, which uses anaccredited third-party testing andquality assurance agency, or admin-istrator, conducting unannouncedperiodic inspections to verify thatsiding products meet or exceed therequirements of those standards.Consumers can confirm that a sid-ing product is certified through

VSI’s program by checking packagelabeling, brochures and Web sitelistings. The extensive use of ASTMstandards by VSI’s product certifica-tion program was discussed in anearlier article in SN.2

Model building codes, such asthose published by the InternationalCode Council, have long requiredthat vinyl siding meet the require-ments of ASTM D 3679. But until re-cently the requirement lacked en-forceability — the code did notrequire documentation of initial orongoing compliance. Now, startingwith the 2006 editions, the Interna-tional Building Code and Interna-

tional Residential Code both requirethat compliance with D 3679 be cer-tified through a third-party qualitycontrol agency. Code officials will beable to confirm such certificationthrough package labeling that canonly be applied if compliance withthe ASTM standard has been verifiedthrough an independent agency.This new requirement provides a keylink in the chain from developmentof an ASTM product performancestandard to consumer satisfactionwith the products manufactured un-der that standard.

ASSURING PROPERINSTALLATIONAs with most building systems,

the performance of a finished prod-uct is only as good as its installation,and ASTM standards also addressthat essential element. ASTM D4756, Practice for Installation ofRigid Poly(Vinyl Chloride) (PVC)Siding and Soffit, provides compre-

F e a t u r e

THROUGH ACTIVE IMPLEMENTATIONand verification of adherence to ASTM standards,the Vinyl Siding Institute has developed a three-pronged aproach to enhancing consumer satisfaction with its products.

BY DAVID S. JOHNSTON

V

www.astm.org | ASTM STANDARDIZATION NEWS | MARCH 2006 || 37

Build Consumer Confidence

Reprinted with permission from ASTM Standardization News (March 2006)

hensive and detailed requirementsfor the proper installation of sidingfor a variety of building types andcladding configurations. In con-junction with the manufacturer’sinstallation instructions, this stan-dard helps ensure that installed vinylsiding will look attractive, be prop-erly secured to the building, allowfor expansion and contraction overthe expected temperature range, andproperly manage moisture over thewall surface and building penetra-tions, among other critical perfor-mance criteria.

The manufacturer’s installationinstructions are coordinated with D4756 through a reference in ASTM D3679. Certain installation details setforth in the instructions are verifiedthrough testing under D 3679. Forinstance, the type, size, penetrationdepth and minimum spacing of fas-teners to be specified in the instruc-tions are used during windload test-ing under D 3679 and its referencedstandard, D 5206, Test Method forWindload Resistance of Rigid Poly(Vinyl Chloride) (PVC) Siding. Codeofficials can be assured that if the fas-tening requirements expressed in theinstructions are followed, the in-stalled siding will comply with the

minimum windload resistance stan-dards in effect for their locality. Andconsumers can be confident that, ifproperly installed, the siding will stayon the building during the worststorm likely to occur in their area.

But proper installations requirequalified installers, and once againASTM standards are playing a keyrole. VSI has established a CertifiedInstaller program based on ASTMD 4756. The program targets all lev-els affecting the installation process,examining the ability of installationcompanies to maintain adequatequality control procedures, the abil-ity of trainers to effectively conveyaccurate information, and the fieldinstaller’s knowledge and under-standing of proper installation tech-nique. VSI certified installer candi-dates are provided a thorough,several-day training program cover-ing the requirements of D 4756 andaccepted industry practices, andmust pass a final examination basedon that standard and other proveninstallation techniques. VSI-certi-fied companies can use the creden-tial to build consumer confidence intheir ability and commitment tohigh quality installations, VSI-certi-fied installers can proudly show

their identification badges on thejob site, and VSI-certified trainersteach the next generation of in-stallers the proper techniques.

ASTM D 3679 and its referencedstandards, coupled with productcertification and building code en-forcement, ensure that vinyl sidingwill meet exacting product perfor-mance standards. ASTM D 4756,coupled with the manufacturer’s in-structions, building code enforce-ment, and trained, certified in-stallers, ensures that the sidinginstallation will allow the product toperform properly and avoid con-sumer dissatisfaction. But until re-cently, something was missing.

THE NEXT BIG STEP: COLORRETENTIONWhat do consumers value most

in their vinyl siding? Its ability tomaintain its appearance after yearsof exposure to the elements and,more specifically, its ability to resistobjectionable color change over itsexpected lifetime. While ASTM D3679 includes basic weatherabilityrequirements, it lacked a rigorousmethod for verifying that the origi-nal color would be retained withinreasonable limits. That shortfall hasbeen rectified with the 2003 publi-cation of a new standard, ASTM D6864, Specification for Color andAppearance Retention of Solid Col-ored Plastic Siding Products.

Standard D 6864 provides astandardized and consistent methodof measuring and evaluating the de-gree of color change occurring insiding products after a period ofoutdoor exposure. It includes limitson the acceptable amount of colorchange based on perceptual studiesof color change tolerance for differ-ent classifications, or regions, of col-ors. D 6864 brings a level of sophis-tication to the difficult subject ofcolor retention not previously avail-able in the vinyl siding industry.

Color retention testing of vinylsiding products is, of course, notnew. VSI began sponsoring indus-try-wide outdoor weathering stud-ies in 1985, in a study that is still on-going and providing useful data.Approximately every five years

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Table 1: Selected ASTM Standards Referencedby ASTM D 3679 and D 4477

D 618 Practice for Conditioning Plastics for Testing

D 635 Test Method for Rate of Burning and/or Extent and Time of Burningof Plastics in a Horizontal Position

D 696 Test Method for Coefficient of Linear Expansion of Linear ThermalExpansion of Plastics Between -30°C and 30°C with a VitreousSilica Dilatometer

D 1042 Test Method for Linear Dimensional Changes of Plastics UnderAccelerated Service Conditions

D 1435 Practice for Outdoor Weathering of Plastics

D 2244 Practice for Calculation of Color Tolerance and Color Differencesfrom Instrumentally Measured Color Coordinates

D 2457 Test Method for Specular Gloss of Plastic Films and Solid Plastics

D 4226 Test Methods for Impact Resistance of Rigid Poly(Vinyl Chloride)(PVC) Building Products

D 4477 Specification for Rigid (Unplasticized) Poly(Vinyl Chloride) (PVC)Soffit

D 4756 Practice for the Installation of Rigid Poly(Vinyl Chloride) (PVC)Siding and Soffit

D 5206 Test Method for the Windload Resistance of Rigid Poly(VinylChloride) (PVC) Siding