Cookies disclaimer

I agree Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our website without changing the browser settings you grant us permission to store that information on your device.

Mastic Asphalt Roof Renewal

Asphalt Roof Renewal | RJ Evans Specification

On Cork, Mineral Wool, Cellular Glass, Perlite, Rigid Urethane (PIR), Phenolic or Composite Insulation on Existing Built-Up Roofing or Mastic Asphalt

Two coats of mastic asphalt R988 T25 to a total thickness of 20mm laid on to sheathing felt. The surface is to be painted with solar reflective paint or stone chippings are to be embedded in bitumen based adhesive.

Or:

Two coats of 20mm polymer modified asphalt laid on sheathing felt. The surface is to be painted with solar reflective paint or stone chippings are to be embedded in bitumen based adhesive.

Preparation

The existing structure must be sound. All insulation which above the deck should be dry. If any of the insulation is wet it should be replaced. The waterproofing should be rot free, sound and not saturated with water. If there is any stone chipping surfacing it must be removed. If this is not possible, a layer of type 3B or similar may be bedded in hot bitumen to provide a suitable surface to accept insulation.

Thermal Insulation

The new insulation will isolate the old waterproofing from the new waterproofing. It will also improve the overall insulation of the roof. The U value of the total construction will be dependent upon the following factors:

1) The type and the thickness of the  insulation used in the existing construction.

2) The type and thickness of the new insulation.

Tapered insulation can be introduced to improve drainage.

Please click the following link for more information: Asphalt Roofing