How to install roll roofing?

The term “roll roofing” combines different materials and technologies that are used for roofs with a small slope — from 0:12 to 3:12.

In residential construction, two options are most often chosen: roll roofing with the “peel-and-stick” principle or coverings made of modified bitumen.

Ever wondered how this type of roofing is installed? Installing a new roof is not an easy task, but it is quite achievable. In this material, we will look in detail at how the installation process takes place.

Step 1: Roof Preparation

Before starting the installation of roll material, it is important to carefully prepare the roof surface. Remove all debris — it can be swept away with a broom or cleared with a blower; make sure nothing interferes with the work. Check the fasteners: screws and nails must be held firmly.

It is equally important to consider weather conditions. It is recommended to carry out the work at a temperature of no less than +40 °F (about +4 °C); otherwise, installation difficulties may occur. If there are damaged wooden elements on the roof, they should be replaced in advance.

Step 2: Deck Cleaning

Check the condition of the deck: it must be strong, dry, and clean, free of debris, dust, oil, or signs of standing water. If necessary, carry out repairs and sweep the surface thoroughly.

Lay out the rows: roll roofing has a standard width of 36 inches and is installed with an overlap. To keep the installation straight, apply chalk lines in advance. For the underlayment layer, make marks every 35 inches; for the top layer — every 32 inches. This spacing ensures proper seam overlap.

Step 3: Apply Roofing Cement to the Edges

Roofing cement is used as a strong adhesive compound that provides reliable bonding of materials. When installing roll roofing, it is applied in key areas of the structure. Start by treating the edges before securing the first sheet. For convenience, use a caulking gun, and then spread the cement evenly with a brush.

Step 4: Attach the Underlayment

Unroll the first layer of roofing material so that it extends beyond the eave edge by about 6 mm (¼ inch). Depending on the chosen type of covering, either fasten it with nails or glue it to the base.

If mechanical fastening is used, place nails or fasteners every 8–10 inches (20–25 cm). When driving in the fasteners, move backward — this helps stretch the material properly. Also make sure the fasteners are no closer than ¾–1 inch (2–3 cm) from the edge.

Step 5: Attach the Second Sheet

After laying the first layer, coat its edges with roofing cement. Before installing the second sheet, also apply adhesive to its underside to ensure reliable bonding at the seams. The second sheet should overlap the first by 4–6 inches (10–15 cm). The fastening method depends on the material: in some cases, special screws are used, in others — heating with a roofing heat gun.

To lay the material evenly, mark the lines with chalk. Once you have ensured the correct position, secure the second sheet with the chosen method. When heating the roofing, go over the entire surface and check that no areas remain unheated.

Step 6: Seal the Vents

If the roof has ventilation outlets, they must be carefully sealed with roofing cement. First, cut an opening of the appropriate size so that the vent cover completely overlaps it. Apply a layer of roofing cement along the edges, then install the cover and press it down so it fits tightly against the surface. If necessary, secure the piece with roofing nails.

Step 7: Cover the Valleys

After laying the two main sheets, it is necessary to cover the valleys. To do this, cut a strip of roofing material about 18 inches (45 cm) wide and lay it over the joint, first coating the edges with roofing cement. Smooth the sheet carefully and secure it with nails or screws, placing the fasteners 8–12 inches (20–30 cm) from the center.

Then add another layer of roll roofing about 36 inches (1 meter) wide. Before installation, coat the edges with cement again and fasten the material according to the recommendations for the chosen type of covering.