Core TradesQuestion 157 of 700
The R-value of an insulation material is a measure of its:
a.Fire-resistance rating
b.Resistance to heat flow (thermal resistance)
c.Density
d.Vapor permeability
Explanation
R-value quantifies thermal resistance; a higher R-value means the material slows conductive heat flow more effectively. It is the inverse of the U-factor. R-value does not directly indicate fire rating, density, or how readily vapor passes through the material.
Practice all 700 questions free — no signup required.
Related questions on this topic
- In an open valley on a shingle roof, metal valley flashing is installed primarily to:
- A drip edge at the eaves and rakes of a shingle roof functions primarily to:
- A roof has a total surface area of 2,000 square feet. Adding a 15% allowance for waste, hips, and starter courses, how many roofing squares should be ordered?
- In a heating-dominated (cold-winter) climate, a vapor retarder in an exterior wall is generally installed on which side of the insulation?
- Under current California Energy Code prescriptive requirements, wood-framed ceiling/attic insulation in most climate zones must reach a MINIMUM of about:
- A wall uses R-15 cavity batt insulation plus R-6 continuous exterior rigid insulation. Ignoring framing and air films, what is the combined nominal thermal resistance of these two insulation layers?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against California CSLB General Building (B) Trade Examination · How we review