PVC-KEE Roofing Membrane Installed – 217,000 Square Feet

PVC-KEE single ply roofing membrane was selected as a lightweight upgrade to this large, low rise, single tenant, office building in Ventura County, California. Office environments have a very low tolerance for roof leaks compared to retail or commercial/industrial properties. We were able to deliver the completed Project significantly under budget. (See our Commercial Roofing page for cost and quality control specifics.)

Large single ply roofThe building had recently completed a “sale-leaseback” to a major financial institutional tenant. The new owner wanted a minimum maintenance, energy efficient, long term roofing solution. They had budgeted for replacement, and we were able to include a fully adhered new roofing membrane installed directly over the existing emulsion/acrylic surface, including a twenty year full value, no dollar limit, manufacturer backed warranty. The specified membrane has a successful in service field history of over thirty five years.

Original construction dated from 1981, thirty-three (33) years prior. At the twenty year mark in 2001, a cold process emulsion system overlay with a ten (10) year warranty, including one ply of polyester reinforcement and acrylic surfacing, was installed over the existing “built up” cap sheet roof . Now at thirteen (13) years, defects and leaks were present.

Worn, lifting acrylic surfaceWhile the old acrylic surfacing had lifted in “ponding” areas, the polyester fabric installed toward the uppermost portion of the old asphalt emulsion provided a “biting” surface to assist in creating a physical bond, so while the surfacing had weathered and worn, the roofing material Manufacturer approved installation of the new fully adhered membrane directly over the primed, old surface.

Water based primerThe roof surface was cleaned, then a water based primer applied, to enhance adhesion “tack” strength, and bind residual surface contaminants.




3M CR 20 foam adhesive

3M CR-20 two component, low rise, adhesive foam was used to adhere the membrane in the “field” or main roof area.

A substantial amount of polyester “fleece” is adhered to the back of the membrane. The backing on each roll is destructively tested for adhesion prior to leaving the Manufacturer’s plant.

Single ply counter flashingSolvent based adhesive assures complete bonding of the smooth membrane to vertical surfaces, yet was incompatible with water based acrylic surfacing. The lower portion of existing roofing on the wall was removed, and new membrane fully adhered to the concrete substrate, with the upper edge receiving butyl tape compression seal behind mechanically fastened metal also incorporating a quarter inch sealant ledge.

PVC-KEE single ply roofThe original upper level roof was installed over lightweight insulating concrete with a light gauge vented steel deck. Fully adhering the new single ply membrane was the best option for securement.

This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.