Roof Installation Methods
When it comes to specifying the various installation methods of a roofing system, it is necessary to first specify the roofing system in question because not all installation methods apply to all roofing systems. For example, you do not mechanically-attach a spray polyurethane foam (SPF) roof system because such a method just doesn't apply.
Generally, the most common installation methods are:
This is when nails or screws are used to attach the roof membrane into the roof substrate. If there is a cover board, insulation, a substrate board, or taper system, all such components are fastened together as part of the process.
This is just a fancy way of saying that the roofing system is glued. However, when there are several components to the roofing assembly; i.e., insulation, cover board, etc., the roofing membrane cannot be glued directly to the substrate. The roofing membrane is glued to the next component below it, usually a cover board or the insulation. It is not uncommon to have the insulation and cover board mechanically-fastened into the substrate first, and then the top layer of roofing membrane is then glued to the top of the insulation facer or to the top of the cover board. This hybrid approach often cancels out any benefits experienced from going with a total, top-to-bottom fully-adhered system.
Ballast is another word for weight, usually described as rocks or stones, that are placed on top of a roofing membrane to hold it in place. Some ballasted roofing systems incorporate square concrete pavers that are placed anywhere from side-by-side to a few inches a part.
Usually this applies to restoration systems in which the roofing material (a liquid-applied membrane) is rolled in-place by the use of squeeges or 'paint' rollers.
Usually this applies to either restoration systems or SPF - spray polyurethane foam. Though the products themselves are very different, the installation is done by use of a spraying the material on the roof. It works much like a power washer, which sprays water, though the intensity of the pressure is much less and, of course, the products are very different than water.
For a more detailed look at which of the 2 predominate installation methods - mechanically-attached or fully-adhered - are best for your next roof, review our newsletter article Installation Methods - Which Is Right for Your Roof?