Roof Installation Methods

Not all roofing projects require the same installation methods. Some can actually be detrimental to the existing roof and structure. So it's not a trivial issue.

Learn the facts so you can choose the right solution for you.

Roof Installation Methods

When it comes to specifying the various installation methods of any given 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:

Mechanically-Attached

This is when nails or screws are used to attach the roof membrane into the roof substrate. If there is a coverboard, insulation, a substrate board, or taper system, all such components are fastened together as part of the process.

Fully-Adhered

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. Therefore, the roofing membrane is glued to the roofing component immediately beneath it, which is usually a coverboard or insulation.

It is not uncommon to have the insulation and coverboard mechanically-attached 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 coverboard. This hybrid approach often cancels out any benefits experienced from going with a total, top-to-bottom fully-adhered system.

Why is it done? Simple: Cost!

Is it better? No!

Ballasted

Ballast is another word for "weight." Lots and lots of wight. In this process, rocks and/or stones 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 apart.

Please, stay away from ballasted. It's cheap for a reason and makes investigation and repairs exteremely difficult and expensive.

Roll-Applied

Usually this applies to a system in which the roofing material is rolled in-place. It is most often "attached" to the substrate or roofing component below it by means of torches (yes, actually flames) that melt the ashphalt in the rolled roofing so that it adheres to the roofing component below it.

This is still a common practice. We stay away from it, however. Would you like your new roof to be literally set on fire?

Spray-Applied

In most cases. this method applies to either restoration systems or SPF – spray polyurethane foam. Though the products themselves are very different, the installation is done by 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?

Roof Restoration

This is the process of installing an elastomeric coating to an existing roofing system. It takes advantage of the structural integrity of the existing roofing system, while restoring the overall system to a "like new" condition. This is an excellent option if the circumstances allow. Learn more.