ENGINEERING EVALUATION

Transcription

1 PRIEST & ASSOCIATES CONSULTING, LLC ENGINEERING EVALUATION Fire Resistance Evaluatin f Nichiha Fiber Cement Cladding in Fire Rated Exterir Wall Assemblies Prject N Prepared fr: David Hhenstern NICHIHA USA, Inc E JOHNS CROSSING, SUITE 250 JOHNS CREEK, GA Verdi Rad Slutins fr the TX Office Pleasantn, TX Building Materials Industry Mbile hward.stacy@priestassciates.cm

2 Priest & Assciates Cnsulting Slutins fr the Building Materials Industry Page 2 Abstract The purpse f this evaluatin is t prvide the technical basis fr IBC cde cmpliance recgnitin f Nichiha AWP/EX panels and Sierra lap bard fr use as exterir cladding in fire resistance rated wall assemblies. Priest & Assciates Cnsulting finds that the range f Nichiha fiber-cement based systems may be added as an exterir cladding cmpnent t fire resistance rated exterir wall cnstructins withut detracting frm the fire rating f the assembly. Submitted by, Reviewed and Apprved, Hward Stacy Senir Scientist Deg Priest President

3 Priest & Assciates Cnsulting Slutins fr the Building Materials Industry Page 3 INTRODUCTION The fllwing Engineering Evaluatin (EEV) has been develped t establish the basis allwing fr the recgnitin f Nichiha Architectural Wall Panels (AWP/EX) and Sierra lap bard in cde-cmpliant fire resistance rated wall assemblies. The cncepts prvided herein are based n building cde allwances, listed fire resistance rated wall assemblies and existing knwledge f the test perfrmance f similar listed assemblies. The purpse f this evaluatin is t prvide the technical justificatin that the installatin f Nichiha fibercement based cladding prducts t fire rated ladbearing and nnbearing exterir wall assemblies will nt detract frm the fire resistance rating f the base wall cnstructin. This analysis fcuses n wd and steel stud lightweight gypsum wallbard (GWB) cnstructins. This dcument is intended t prvide an expert pinin n the prperties f the materials, prducts, r assemblies identified in this reprt as related t meeting a specific cde r standard; ther prperties such as (but nt limited t) acustical, weather resistance, durability, txicity level f smke develped during cmbustin, etc., are nt addressed nr implied. DESCRIPTION The Nichiha AWP/EX panels and Sierra lap bard systems are fiber-cement based cladding prducts used fr exterir cladding. The AWP/EX list includes but is nt limited t prducts identified as Illuminatin Series, Architectural Blck, Tuff Blck, Empire Blck, Industrial Blck, Ribbed, RughSawn, Vintage Wd, SandStne, Plymuth Brick, Canyn Brick, Vintage Brick, and Cinder Blck. The Sierra lap siding prducts include prducts identified as Sierra Premium Shake and Savannah Smth. Nichiha panel and lap bard systems are installed t base wall cnstructins in accrdance with the manufacturer s installatin instructins. The range f Nichiha prducts is described in Prgressive Engineering, Incrprated (PEI) Evaluatin Reprt PER The fiber-cement frmula and applicatins are cnsistent fr all Nichiha cladding prducts. Panel and lap siding thicknesses range frm a minimum f ½ in. t ⅞ inch. All Nichiha fibercement siding prducts d nt supprt cmbustin and have a Flame Spread Index rating f 0 and a Smke Develped Index f 0 (ASTM E84 Class A). REFERENCED DOCUMENTS 1. Prgressive Engineering, Incrprated (PEI) Evaluatin Reprt PER Gypsum Assciatin Fire Resistance Design Manual, GA UL Fire Resistance Directry, Vlume 1 4. ASTM E (Reapprved 2013), Standard Guide fr Extensin f Data frm Fire Resistance Tests Cnducted in Accrdance with ASTM E 119 EVALUATION This analysis addresses the allwance fr the installatin f Nichiha fiber-cement claddings t fire rated wall cnstructins which include the fllwing exterir wall assembly ptins: Lightweight framed exterir fire rated base wall cnstructins (steel r wd studs) with gypsum sheathing (cnfrming t ASTM C1396 and/r C1177) Cncrete r cncrete masnry units Fire resistance rated base wall assemblies with ptinal exterir fam insulatin including EPS, XPS and plyiscyanurate rigid fam sheathings

4 Priest & Assciates Cnsulting Slutins fr the Building Materials Industry Page 4 Fire Resistance Rated Wall Assemblies The ASTM E119/UL263 test methds evaluate the duratin fr which test specimens will cntain a fire (resistance t heat transfer t the unexpsed side), retain their standard integrity (ability t sustain a lad), r bth. Generally speaking, Nichiha panel and lap siding systems may be used tgether with the assemblies described in IBC Table 721.1(2) withut changing the assigned hurly rating. In additin, Nichiha cladding systems can be used as exterir wall cladding when installed n any fire resistance rated base wall assembly, including thse listed fr use in GA-600 (Ref. 2), by Underwriter s Labratries (Ref. 3), r by any ther recgnized third party testing and certificatin agency. A wide variety f UL fire rated exterir wall designs include the allwance fr Fiber-Cement Siding with a minimum thickness f ¼ in. and munted in accrdance with the manufacturer s installatin instructins. These designs include but are nt limited t ladbearing wd stud framed cnstructins such as UL V306 r U354 which allw fr the installatin f any fiber-cement siding ver fam plastic exterir insulatin t the wd stud framing. In additin, UL Design Ns. V454 and U425 prvide examples f versatile bearing r nnbearing exterir steel stud wall cnstructins having identical allwances fr fibercement siding. The V306 and V454 designs are summarized t illustrate the brad range f fire rated wall systems and cmpnent applicatins. V306 (Ladbearing wd stud framing) Interir membrane - ⅝ in. type X GWB (limited t USG Type SCX) Framing - Wd studs, nminal 2 x 4 in., spaced a maximum f 24 in. OC Cavity insulatin Optinal, BASF spray applied fam plastic insulatin (limited t specific 0.5 and 2.0 lb SPFs) Exterir sheathing any ⅝ in. type X UL Classified GWB Weather Resistant Barrier (WRB) Optinal, any cde apprved WRB Exterir Insulatin Optinal, Expanded plystyrene (EPS) Exterir claddings Optinal, including aluminum, steel, vinyl, wd, fiber-cement, stucc, brick amng thers. Claddings are fastened ver exterir fam plastic insulatin t wd studs V454 (Ladbearing and nnbearing steel stud framing) Gypsum wallbard Any ⅝ in. type X UL Classified GWB, fastened t interir and exterir sides f the steel studs in accrdance with the listing Framing Minimum 20 GA. steel studs, spaced a maximum f 24 in. OC Cavity insulatin Optinal, glass fiber, mineral wl r varius SPFs per the listing WRB Optinal cde apprved Exterir insulatin EPS, XPS, Plyiscyanurate rigid insulatin, varius SPFs Exterir claddings Varius generic sidings including aluminum, steel, vinyl, wd, fibercement, stucc, brick amng thers. Claddings are fastened ver exterir fam plastic insulatin t steel studs The allwance fr the installatin f Nichiha fiber-cement siding prducts t the exterir f fire rated base wall cnstructins is justified by Rule 2 f Harmathy s Ten Rules f Fire Endurance (Ref. 4): The fire endurance f a cnstructin des nt decrease with the additin f further layers. The additin f fiber-cement siding t ladbearing and nnbearing base wall assemblies has als been shwn in Intertek Design Ns. JH/FCS and JH/FCS that representative fiber-cement siding prducts can imprve the fire resistance rating f a base wall assembly. The referenced listings prvide fr 1 hur ratings when minimum ¼ in. fiber-cement siding is installed ver steel and wd stud wall

5 Priest & Assciates Cnsulting Slutins fr the Building Materials Industry Page 5 assemblies cnstructed with ½ in. type X 1 GWB n the exterir face and ⅝ in. type X n the interir face. UL Design N. U317 gives a 45 minute rating t a wd stud bearing assembly with ½ in. type C GWB munted t bth sides. The fact that the fire classificatin is imprved t 1 hur by the additin f fibercement siding is indicative f the added fire resistance time that culd be expected by the installatin f Nichiha sidings t a similar cnstructin, althugh this must be verified by actual full scale fire testing. These bservatins are included in this analysis t prvide additinal evidence that the Nichiha fibercement sidings will at a minimum, nt detract frm the fire rating f wall assemblies when tested in accrdance with ASTM E119. CONCLUSION Priest & Assciates Cnsulting has prvided herein the technical justificatin fr the cde cmpliance f Nichiha AWP/EX and Sierra lap fiber-cement siding systems as exterir cladding fr varius fire resistance rated exterir wall assemblies when installed in accrdance with Nichiha installatin instructins. 1 Since generic ½ in. type X GWB is n lnger prduced in Nrth America, it is assumed that this is actually ½ in. prprietary type C, althugh the manufacturer is nt listed.