Tuesday, November 8, 2011

Single-Ply Membranes are Good for Most Re-Cover Jobs

The options are widespread with single-ply membranes. There are two major generic types of membranes with three major generic types of installation methods. There are the thermoset membranes — cured membranes with seams that are sealed with adhesives — and thermoplastic membranes with seams that are heat- or solvent-welded. The systems are either fully adhered, mechanically attached, or loose-laid and ballasted.

Single-ply membranes are good choices for most re-covers because they are lightweight and can re-cover almost any deck type. Single-ply membranes are a good choice when first cost is the overriding factor in the installation because they usually are less expensive to install.

EPDM is worth considering when the roof is wide open with large empty expanses because it is available in 10- and 20-foot wide rolls, minimizing seams. In these situations, repairs to membranes using electrical heat welders may be a problem without a very long extension cord. On the other hand, for roofs with densely packed, multiple penetrations, thermoplastics offer smaller roll sizes; membranes with large roll sizes are more difficult to install around closely packed penetrations.

Mechanically attached membranes are generally not the preferred way of installing single plies over structural concrete decks but are good for use on steel or wood. A fully adhered or ballasted system is more appropriate for structural concrete to avoid damage to the concrete.

Single-ply membranes should be evaluated for chemical composition if they are being installed where hydrocarbon emissions are a problem. PVC- and EPDM-based membranes are sensitive to hydrocarbons, such as oil, cooking grease and jet fuel, and should not be used. Specialty formulations of single plies are available for applications where these emissions are a problem.

Look for a Conklin Roofing Systems contractor in your area:

Patton Services | (309) 303-3128 | rpatton55@comcast.net | http://www.whiteroofingsystems.com

No comments:

Post a Comment