If a roofing contractor offers an insulation material with an R value of 2.5 instead of 3?
Thursday, June 19th, 2008 at
8:43 am
Aielmanshelp asked:
Would it be worth forwarding the offer to the client? Is the difference that substantial?
Tagged with: Insulation Material • Insulation Value • Roofing Insulation
Filed under: Engineering
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herts replacement roof
You don’t want that. If he offers 3.5 instead of the required 3, that is a different story. Otherwise he should give you more material thickness to provide an equivalent R of 3.
Yes, the difference can be substantial and I wouldn’t forward it to the client. The smaller the R value of the entire roof sandwich the larger the difference it makes. Like the change from 5 mpg to 4 mpg is a 25% worsening in fuel economy, but a change from 100 mpg to 99 mpg is 1%.
It will mess up the heating/cooling of the building and the mechanical systems might be inadequate. They could save money on the roof and complain how the building is too hot/too cold or the mechanical systems never shut off and their energy bills are too high.