Insulation
Insulation is available in varying types, thicknesses and sizes. Should the manner of attachment as suggested conflict with that specified by the individual insulation manufacturer, the insulation manufacturer’s specifications shall be followed and in addition, shall be in compliance with Koppers General Requirements.

An evaluation of the dew point and its effect on the roofing system should be determined by the building owner’s representative.

Good roofing design indicates that the following points be considered when specifying board type roof insulation:
  1. The roofing insulation must be kept dry at all times. It must be a type approved by Koppers for use with a Koppers built-up roof. It should only be applied over a deck complying with Koppers General Requirements.
  2. In areas where the roof slope may exceed the maximum prescribed for Koppers Roofing Specifications (see Slopes), the insulation specified must be able to retain nails or wood nailers must be specified to be installed perpendicular to the slope at each course of insulation. Spacing of nailers must be such that the insulation fits snugly between the nailers but must not be force fitted.
  3. When one (1) layer of roof insulation is specified on a metal deck, Koppers requires the insulation be mechanically fastened and the first ply of the built-up roofing system be a base sheet solidly mopped in steep asphalt.
  4. When more than one (1) layer of roof insulation is to be specified on a metal deck, Koppers requires the first layer be mechanically fastened and the subsequent layers be solidly mopped in steep asphalt.
  5. Koppers requires glass fiber insulation be installed as the membranes substrate in configurations when the insulation is bound (encapsulated) by impermeable materials. Contact your Koppers representative for details on insulation thickness requirements.
Koppers supports the NRCA position recommended in Bulletin #9 dated Sept., 1988, recommending overlays over closed cell insulations; therefore, it is required for roof warranties that when isocyanurate or isocyanurate composite roof insulations are specified, an overlay board of perlite, fiberboard or glass fiber roof insulation applied in hot bitumen must be installed.

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