R-40 JM insulation is a high-performance fiberglass insulation manufactured by Johns Manville. It is designed to provide excellent thermal resistance for attics and ceiling spaces, helping buildings maintain comfortable indoor temperatures while reducing energy consumption.
What R-40 Means
The R-value indicates how effectively insulation resists heat flow.
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R-40 offers very high thermal performance, ideal for attic insulation.
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Helps reduce heat loss during winter and heat gain during summer.
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Higher insulation levels can significantly lower heating and cooling costs.
Material and Construction
R-40 insulation is made from fiberglass fibers that trap air pockets to slow heat transfer. The insulation comes in thick batt form, designed to fit between attic joists or ceiling framing.
Key features include:
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Lightweight and easy to install
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Non-combustible fiberglass material
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Moisture and mold resistant
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Good sound absorption
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Long-lasting thermal performance
Common Applications
R-40 JM insulation is mainly used in:
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Attic floors
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Ceiling cavities
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Energy-efficient residential homes
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New construction and renovation projects