Screws Or Glue? What Is The Difference?
If you are in the roofing industry it is more than likely you have installed a TPO flat roofing system before. However, the question that comes to mind when you are facing a flat roofing project requiring a TPO membrane is whether or not to go with fully adhered or mechanically attached! What is important is that you know the difference between the two to ensure you install the appropriate roofing system for the project to guarantee it withstands time and our environment.
Mechanically Attached
A mechanically-attached roofing system is a membrane roof that is attached to the substrate; i.e., wood, concrete, steel, etc., by mechanical means. This mechanical attachment could be with screws, concrete nails, augers, etc. The fastener used is almost entirely dependent upon the substrate (type of roof decking). Any insulation, substrate board, or cover board that is a part of the roofing assembly would also be attached into the building’s roofing substrate, either directly or indirectly by means of the direct attachment of the other, adjacent components. Often these “intermediary” components are attached independently of the roof membrane and are done with sufficient fasteners and in a specific pattern so as to achieve particular wind up-lift ratings, if such are required. The membrane roofing system is then installed on top of and through those intermediary components and into the roofing substrate. Since the insulation in a mechanically-attached system is attached separately and then is further secured indirectly when the membrane roof is installed, the number of fasteners required to “fasten” the insulation to the substrate is much lower than a fully-adhered roof.
Benefits
▪ Adaptable to unusual roof configurations
▪ High wind uplift performance
▪ Low material cost
▪ Lightweight
▪ Fast installation
Fully Adhered
A fully-adhered roofing system is a membrane roof that is attached to a roofing substrate indirectly using adhesives, which is just a fancy word for glue. Sometimes the roofing membrane is installed directly on top of the roofing substrate. But usually there is insulation and maybe even a coverboard that is also part of the assembly. If that is the case, then obviously the roof membrane is attached to the insulation (or cover board) instead of directly to the substrate. In such a scenario, the insulation (or cover board) may actually be mechanically-attached to the substrate first and then the roofing membrane is glued to the top of that. Let’s look at this a little more closely
Benefits
• Aesthetically pleasing
• Proven system that has been installed for decades.
• No fluttering in the roof system
• Offers the best manufacturers wind ratings.
• Can be a quiet installation when paired with an olybond installation adhesives.
Fully Adhered TPO System In Renton, WA
Chase Construction NW, Inc. has been working on a commercial roofing project in Renton, WA. for an apartment complex called Heritage Hills. We determined the best roofing system for this project would be GAF’s fully adhered 60 mil TPO. Check out these before and after photos and video of us installing GAF’s fully adhered 60 mil TPO flat roofing system!
