Tips For Installing A Thermoplastic Roof On A Low-Slope Residential Carport

If you are building a carport with a low-slope roof, then a thermoplastic roofing system is the best way to protect it from the elements. Even if you do not have any previous experience installing thermoplastic roofing materials, these tips will help you achieve a quality residential roofing installation:

Tip: Ensure the Carport's Plywood Substrate is Solid and Defect Free

The secret to correctly installing any roofing system and achieving professional results is to start with a substrate that is flat and free from any defects. Just as you prep your walls for painting, so too must you prep your roof's substrate for a roof installation.

Before installing anything else on the roof, first, make sure each section on plywood is solid and free from any defects or damage.

Tip: Install Insulating Foam Boards Under the Thermoplastic Membrane

While low-slope roofs used to be finished by simply painting on a layer of roofing tar, today they are sealed using specialized membranes designed to reflect the sun's harmful rays and extend the life of the roof. 

Before installing the membrane on your carport, first, put down a layer of insulating boards. The insulating boards designed to go between the substrate and a thermoplastic membrane are made of fiberglass, cellulose fibers, and foam.

To install the insulating boards, cut them to size using a utility knife and attach them to the substrate layer using fasteners and galvanized metal roofing screws.

Tip: Choose How to Install the Membrane and Then Use the Correct Technique

Thermoplastic roofing membranes can be put down on your carport in two different ways:

  1. mechanical installation
  2. manual installation

With a mechanical installation, you will lay out the first section of membrane and then attach it to the insulation and substrate using specialized fastening plates and galvanized screws.

When using screws and fasteners, it is imperative you screw the fastening plates all the way down to prevent leaking around the screw shafts.

For a manual installation, you need to paint on a layer of bonding adhesive to the top of the insulation layer. Once the adhesive is tacky to the touch, then you can put down the membrane on top of it.

Finally, once the membrane sections have all been installed, then you need to go over all of the seams with either another layer of bonding adhesive or rent a welding robot designed to weld together two pieces of thermoplastic into a permanent bond.