Johns Manville Roof Insulation Specifications

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Product Datasheets - Alphabetical Listing

Roof Insulation Specifications

The JM Insulation Specification numbering system is designed to allow the designer to easily and clearly describe a particular insulation construction. Arabic numerals denote the number of layers of insulation attached in a particular manner. Capital letters indicate the method of attachment of the insulation and the presence of a vapor retarder.

Capital letters indicate the following:
M = Mechanically Attached
A = Adhered
L = Loose Laid
V = Vapor Retarder
C = Cold Adhesive

Examples:

A construction of one layer of insulation mechanically attached to a structural deck with a vapor retarder and a second layer of insulation mopped in hot asphalt would be described as 1MV1A.
Two layers of insulation in hot asphalt to a structural deck would be described as 2A.
One layer of insulation loose laid on a structural deck would be described as 1L.

Deck Substrate:

S = Steel
W = Wood
L = Lightweight Concrete
C = Concrete
G = Gypsum
T = Cementitious Wood Fiber

Insulation Specification	Insulation Bottom Layer Attachment	Insulation Top Layer Attachment	Deck Substrate
1MV1A 1M1A 1M1C 1A 2A 1C 1L 1L1M 1M 1MV2A V1A V2A	Mech. Attached Mech. Attached Mech. Attached -- Adhered -- -- Loose Laid -- Mech. Attached -- Adhered	Adhered Adhered Cold Adhesive Adhered Adhered Cold Adhesive Loose Laid Mech. Attached Mech. Attached Adhered Adhered Adhered	S, W, L, C, G, T S, W, L, C, G, T S, W, L, C, G, T L, W, C, G, T L, W, C, G, T L, W, C, G, T S, W, L, C, G, T S, W, L, C, G, T S, W, L, C, G, T S W, L, C, G, T W, L, C, G, T

* Insulation must be fully adhered to nailed base sheet.
** Vapor barrier must be adhered to nailed base sheet.