Questions & Answers

The following are some common questions and their answers.:

Q Why choose heat welded seams over liquid sealed seams?

A: By overlapping the membrane and heat welding the seams to 1100°F they become as strong and as watertight as the actual material itself. In addition, by not heat welding the seams and using a liquid seam sealer, there will always be a lip on the overlap that will eventually lift and leak (Usually in about 1 year)

Q Will the vinyl membrane be run up the wall? If so, how far?

A: Yes it will always be run up the wall as follows:

6-8 inches on new construction if the siding will be vinyl, wood, hardi board etc. If stucco will be the exterior finish, the membrane must be run up the wall a minimum of 12 inches for code.

If it is an existing building and the exterior finish is vinyl siding, the first row is removed, flashing is installed, the membrane is run up the wall, then the siding is replaced .If the siding is wood or hardi board it will be cut up 2-3 inches to allow for a 90° inside galvanized flashing to be installed then the membrane will be run up the wall. The same procedure will be used if the exterior finish is stucco.

Q How important is deck preparation?

A: It is very important, in fact it is the key factor to having a professional looking deck installed. Most of the process of the installation requires great detail to:

  • Flashing install
  • Sanding the plywood
  • Floor levelling compound

I have a personal rule; Apply the levelling compound right the first time and spend less time (or none) Grinding it down to prepare it for the second and third coat. The better you do the job with deck preparation, the better the finished deck will look.

Q What is the recommended plywood thickness and grade?

A: The recommended substrate is 5/8″ T&G Fir select or good one side plywood. Personally i favour 3/4″ T&G plywood as it is much stronger but it is entirely up to the homeowner. In either case it must be glued to the floor joists using construction grade sub floor adhesive.

Q What bonding agent is used to attach the vinyl membrane to the plywood?

A: I have always used roll on HB FULLER contact cement. Unlike the latex adhesive a deck installed with contact cement can be used immediately after the job is completed ,gassing off bubbles are kept to a minimum, corners and edges are wrapped tighter as the glue dries quicker and will allow the membrane to stay conformed to these areas.

Q Should wooden posts on the deck be wrapped with vinyl membrane?

A: Yes they should. First the post must be clad in 90° inside galvanized flashing, then a vinyl strip will be wrapped around the post and overlapped onto the deck membrane, then heat welded to form a watertight seal. This way relying on silicone for waterproofing will be eliminated.