WFE-4. CSI 3-Part Specifications.

	BITUMINOUS FLASHINGS
	Specification WFE-4

Specification WFE-4

General

Note: All general instructions contained in the current JM Commercial/Industrial Roofing Systems Manual shall be considered part of this specification.

The construction shown above should be used with light gauge metals such as copper, hot galvanized steel or aluminum. When bonding modified bitumen materials to metal, Johns Manville (JM) requires cleaning the metal to remove any oil, grease, etc. The metal surface receiving the flashing should then be coated with metal primer. The primer must be allowed to completely dry before any flashing material is installed.

Flashing material should not be torched directly to metal. The APP flashing sheet should be placed on the roof up-side down, making certain that the roof membrane is protected. Heat the flashing so that the surface has a sheen on it. The flashing material is then picked up by the edges and positioned as required. The flashing sheet should extend a minimum of 4" (102 mm) beyond the gravel stop, onto the surface of the finished roof. Flashing sheets should be installed in sections no longer than 39 3/8 " (1 m) to avoid material being too cool when set in place.

All laps must be rolled with a 3" (76 mm) rounded edge roller. A minimum 1/8 " to 3/8 " (3 mm to 10 mm) bleedout of APP compound shall be visible at the edge of all laps. If the compound bleedout is not accomplished, heat a trowel with a propane flame, lift the lap, apply a flame to both sides of the lap area and smooth the melted compound with the trowel to form an even seal.

Specification WFE-4

This detail shows another method of treating roof edges utilizing a combustion resistant cant strip to further raise the metal edging above the roof level.

For roofs without parapets or copings, a metal edging is usually employed to give a building a finished appearance. This edging covers the junction between roof and sidewall and provides a decorative fascia for the building.

Prior to the application of any metal edging the flashing is to be carried up over the tapered edging strip and secured to the wood nailer.

Caution: Improper use of these materials and application equipment can result in severe burns, and/or damage to property. The mechanic must install these materials using the techniques recommended by JM and those found in "A Guide to Safety: Torch-On Modified Bitumens" available from the Asphalt Roofing Manufacturers Association.

For an identical copy of this specification, ask for RS-4324.