CHAPTER 8 CONSTRUCTION DETAILS - Progressive Materials

1 CHAPTER 8 CONSTRUCTION DETAILS provides technical information concerning the design and installation ofconstruction DETAILS for quality SPF roof systems. This introduction is intended to supplement the special notes on the individual CONSTRUCTION DETAILS are provided for the following SPFroof system types: SPF roof systems with protective coatings SPF re-cover roof systems with protective coatingsConstruction DETAILS applicable to SPF roof systems withprotective coatings are denoted as SPF- followed by anumber and possibly a letter ( , SPF-2, SPF-2A). CONSTRUCTION DETAILS applicable to SPF re-cover roof sys-tems with protective coatings are denoted as SPF(R)- followed by a number and possibly a letter ( , SPF(R)-1, SPF(R)-1A).The letter designation after an SPF roof system type des-ignation and number identifies NRCA s order of preferencefor addressing a specific detail condition. For example, CONSTRUCTION Detail SPF-3 Base Flashing With Coun-terflashing depicts NRCA s preferred method of address-ing a base flashing with counterflashing detail for SPFroof systems with protective coatings.

2 CONSTRUCTION De-tail SPF-3A Base Flashing depicts an alternative detailNRCA also considers acceptable based on any limitationsdescribed on the alternative CONSTRUCTION Information Applicable to All CONSTRUCTION DetailsThe CONSTRUCTION DETAILS in this manual provide a genericconcept for each specific detail type shown. NRCA s CONSTRUCTION DETAILS likely will require modification tomeet a project s specific requirements. It is a designer s responsibility to adapt the CONSTRUCTION DETAILS to a project s makes these CONSTRUCTION DETAILS available in acomputer-aided design (CAD) format to allow users tocustomize these CONSTRUCTION DETAILS using their own CADsoftware applications to suit their specific project information contained in this manual is intendedCHAPTER 8 CONSTRUCTION DETAILSThe NRCA Roofing Manual: metal Panel and SPF Roof Systems 2012333 The NRCA Roofing Manual: metal Panel and SPF Roof Systems 2012 SPF Roof Systems| CHAPTER 8 CONSTRUCTION Detailsprimarily to address CONSTRUCTION DETAILS applicable tonew CONSTRUCTION .

3 When considering reroofing projects,the Reroofing Manual section of The NRCA RoofingManual: Architectural metal Flashing, CondensationControl and Reroofing should be consulted regarding thedecision to re-cover or remove existing roof systems andfor general information applicable to reroofing low- andsteep-slope roof systems. Once this decision is made,most information contained within this CHAPTER can alsoapply to suggests this CHAPTER be used in the design of roofsystems only after a number of criteria have been carefullyconsidered, including: Climate and geographic location A building s intended use and design life expectancy Exterior and interior temperature and humidityconditions Code requirements Type of roof deck Slope and drainage A roof s configuration Building movement Fire, wind and impact resistance Type and amount of insulation needed Need for ventilation Maintenance, repair and reroofing Compatibility with adjacent components, in-cluding potential material discharge onto a roof CONSTRUCTION sequencing Worker safety Potential building additions Odors, noise and dust generated by certain system application methods Rooftop traffic Reflectivity or emissivityThese criteria play important roles in the success or fail-ure of every roof assembly and must be considered by adesigner to determine the appropriate components of aroof assembly, applicable specifications and constructiondetails to be addition.

4 NRCA recommends designers consider thefollowing factors for SPF roof Components:Components that may be pro-vided or installed by other trades that are integrated intoroof systems can be critical to the weathertight integrity ofcompleted roof systems. These components may include: metal counterflashings at curbs and other penetrations Lead flashings, drains and plumbing vent stacks Drain heads, clamps and strainers Sheet- metal vents Sheet- metal pitch pans Through-wall flashings Skylight components and flashings Smoke hatch components and flashings Expansion joints and related components Wood blocking and attachment Pipe or conduit supports Crickets and saddles Siding or cladding Chimney caps Wall cladding Permanent safety anchors or guardrails Microwave or satellite dish components Lightning protection arresters and cables Photovoltaic systemsDefinition of responsibility for the above componentsshould be determined prior to job Assembly Components Deck, Insulation and SPF: In all the CONSTRUCTION DETAILS , unless otherwise noted, the primary compo-nents of each CONSTRUCTION detail are illustrated as generic NRCA Roofing Manual.

5 metal Panel and SPF Roof Systems 2012 SPF Roof Systems| CHAPTER 8 CONSTRUCTION Details335 The NRCA Roofing Manual: metal Panel and SPF Roof Systems 2012 SPF Roof Systems| CHAPTER 8 CONSTRUCTION DetailsWood Nailers and Blocking: Many of the con-struction DETAILS illustrated in this manual depict woodnailers and blocking at roof edges and other points ofroof termination. Wood nailers must be adequately fas-tened to the substrate below to resist uplift loads. This especially is true at parapet walls and copings and roofedges where edge- metal shapes are fastened to other advantages, the nailers provide protection forthe edges of rigid board insulation and provide a substratefor anchoring flashing Materials . Wood nailers should bea minimum of 2 x 6 nominal-dimension provide an adequate base, nailers should be securelyattached to a roof deck, wall and/or structural framing. In the design of specific DETAILS for a project, a designershould describe and clearly indicate the manner in whichwood nailers and/or blocking should be incorporated intoconstruction DETAILS .

6 A designer should specify the meansof attachment, as well as the fastening schedule for allwood nailers and Wood: Preservative-treatedwood available for consumer use no longer is treated withchromate copper arsenate (CCA). Some commercial usesof CCA are still available. The new treatment processesuse alkaline copper quat (ACQ), copper azole (CBA),sodium borates (SBX), ammoniocal copper zinc arsenate(ACZA) or variations of these compounds. Most treat-ments except SBX are more corrosive than CCA and re-quire fasteners, anchors and connectors of specific com-position to resist suggests the following guidelines when encounter-ing the current generation of treated wood: Carbon steel, aluminum and electroplated gal-vanized steel fasteners and connectors shouldnot be used in contact with treated wood. Hotdipped galvanized fasteners complying withASTM A153, Standard Specification for ZincCoating (Hot-Dip) on Iron and Steel Hard-ware, and connectors complying with ASTMA653, Standard Specification for Steel Sheet,Zinc-coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip Process, Class G185, generally are acceptable.

7 Type 304 orType 316 stainless-steel fasteners and connectorsare recommended for maximum corrosion resistance. Fasteners with proprietary anti-corrosion coat-ings may be acceptable for use with treated the use of such proprietary coated fasteners andconnectors is being considered, fastener manufacturersshould be consulted for specific information regard-ing the performance of their products in treated woodand any precautions or special instructions that may be applicable. Aluminum fasteners, flashings and accessoryproducts should not be used in direct contactwith any treated wood. ACQ-treated wood isnot compatible with aluminum. Uncoated metal and painted metal flashings andaccessories except for 300-series stainless steelshould not be used in direct contact with treatedwood. metal products except stainless steel maybe used if separated from treated wood by aspacer or barrier, such as a single-ply membraneor self-adhering polymer-modified bitumenmembrane.

8 SPF will not bond well to treated wood andmay need primers or mechanical means to ensure is of the opinion the corrosion-related concernsregarding the use of the current generation of treatedwood possibly outweigh the benefits that treated woodprovides as a component in roof assemblies. In many in-stances, the use of nontreated, CONSTRUCTION -grade wood issuitable for use in roof assemblies as blocking or nailersprovided reasonable measures are taken to ensure thenontreated wood remains reasonably dry when in a specific CONSTRUCTION detail provides for a sec-ondary means of waterproofing, NRCA now considersthe use of nontreated, CONSTRUCTION -grade wood to be anacceptable substitute for treated Components:A majority ofthe CONSTRUCTION DETAILS illustrated in this manual depictjob-site-fabricated CONSTRUCTION . Many roof system manu-facturers offer prefabricated flashing components or haveguidelines that permit the use of Materials other thanthose indicated in these DETAILS .

9 Flashing Materials mayvary greatly; individual manufacturer s requirements shouldbe examined and evaluated for CONSTRUCTION and Clearance:Roof drains, penetrationpockets and vertical sides of curbs often have particularinstallation or attachment requirements, which follow: Interior roof drain bowls and under-deck clampstypically are furnished and installed by rings and dome strainers generally arefurnished by others and installed by a roofingcontractor. Prefabricated flashing, metal sleeves and curbswith premolded pipe flashings are preferred forsealing pipes or irregularly shaped support pockets or pitch pans are acceptableas a last alternative. Pourable sealer is the recom-mended top fill material for penetration pockets. Vertical wood curb nailers may be secured to astructural member or the roof deck using addi-tional wood blocking, metal angle supports, or acombination of wood and metal . Curbs mayconsist of prefabricated (insulated where appro-priate) metal curbs and, when securing flashingis necessary, should have nailers at the top edge.

10 The maximum amount of space should be provided be-tween pipes, walls and curbs to facilitate proper installa-tion of SPF and flashings. NRCA recommends a mini-mum of 12 inches of clearance between pipes, a mini-mum of 12 inches of clearance between pipes and curbsor walls , and a minimum of 24 inches of clearance be-tween walls and curbs. SPF roof systems may have differ-ent installation methods that may require different spac-ings, and certain project conditions may not allow theserecommended clearances. However, adequate space ( ,clearance) is required for a mechanic to properly installthe required flashings at these locations. Refer to Figure8-1. Structural supports that penetrate vertically throughthe roof membrane preferably should be square or , L- and T-shaped structural supports are not preferredbecause they are difficult to flash properly and may be aconstant maintenance NRCA Roofing Manual: metal Panel and SPF Roof Systems 2012 SPF Roof Systems| CHAPTER 8 CONSTRUCTION DetailsFigure 8-1: Guide for clearances between pipes, walls and curbsFastener Spacing:Fastener spacing for gasketed fas-teners depicted in the CONSTRUCTION DETAILS generally is be-tween 8 inches and 24 inches.