Value Engineered Roof Assemblies
Insulation assembly pre installed r value overall u factor for roof assembly overstated perforance 1 minimum r value assembly listed in.
Value engineered roof assemblies. 4 check assembly for compliance with the minimum requirements. Compare rsi eff determined in step 3 with the minimum requirement for the assembly. Try to reduce the number of roof truss profiles to two or three and keep roof pitches reasonable for transport and assembly costs. Insulation in this case will be below the roof deck or considered part of the ceiling assembly.
The r value you have to achieve will be a big part of figuring out the type and thickness of the insulation you will install. Normative appendix a of the 90 1 standard rated r value of insulation and assembly u factor c factor and f factor determinations provides pre calculated assembly u factors for metal building insulation assemblies metal building roofs. The rsi eff must be equal to or greater than the total effective rsi value required in table 2 of the 2012 esnh standard or the chosen level of insulation in the applicable builder option package. He specifically helps the construction industry meet its design expectations faster and more efficiently for rain screen wall systems and metal roofing.
1 percent based upon comparing differences in u factors from 2013 and 2010 versions of standard of the same r value assembly. 8 girts spaced 5. Calculation based on standing seam roof ssr system table 4 wall assembly u factors thermal break cavity insulation wall u factor1 none r16 mbi 0 074 none r19 mbi 0 066 1 8 foam r25 mbi 0 057 1 8 foam r30 mbi 0 049 certifi ed r13 r30 mbi 0 042 1. He is proud to continue engineered assemblies tradition of uniting the house of design with the field of construction by providing the best products and services to canada s architectural.
At least ten north american roofing companies offer vegetated roof assemblies as standard auxiliary products and more companies are entering the field all the time. Calculations based on owens corning optiliner system. R value method u factor method c402 1 3 insulation component r value based method c402 2 and c402 4 c402 2 2 2 roof assembly table c402 1 3 c402 2 3 above grade walls table c402 1 3 c402 4 fenestration c402 4 through c402 4 4 and table c402 4 daylight controls fenestration sections above and c405 2 3 1. Roofnav roofnav is a free web based tool developed by fm approvals that provides fast access to the most up to date fm approved roofing products and assemblies.
Apa performance rated i joists pris are manufactured in accordance with pri 400 performance standard for apa ews i joists form x720 this performance standard provides an easy to use table of allowable spans for applications in residential floor construction allowing designers and builders to select and use i joists from various member manufacturers using just one set of span.