How to Install a Roof Cap

Applying Roof Shingles
What You'll Need
50 foot tape measure
Roof cap or shingles
Roofing nails
Utility knife
Roofing cement

When it comes to finishing off a roof project, the roof cap is the most important. A roof cap covers the ridge of a roof in order to deflect water down the sides instead of onto the roofing material. Roof caps are available in many different styles from individual shingles to pre-fabricated caps that run the length of the ridge line. Installing a roof cap is an easy process, but does require some attention to detail for eliminating water damage. Here are the steps to take to install a roof cap yourself.

Step 1 - Measure Roof for Materials

Walk along the ridge of your roof and measure it with the 50 foot tape. If you feel that the roof is going to be longer, use a 100 foot tape. This measurement will help to determine the number of shingles you will need, or the number of pre-fabricated roof caps.

Step 2 - Measure Both Sides of Ridge Line

blueprint and tools

Once you have the roof cap purchased you can begin the installation process. Measure both sides of the ridge line to six inches below the line. With the measurement marked, run a chalk line along the roof at this six-inch mark and snap the line. Do this for both sides.

Step 3 - Place First Shingle for Roof Cap

If using individual shingles for the roof cap, then start at the outside edge of the roof and lay down the first shingle. Lay the shingle so that it lies on both sides of the roof down to the chalk line. It should also be overlapping the last row of shingles by two to three inches. Secure it to the roof with a roofing nail two inches below the ridge line and just above the tar line.

Step 4 - Place Second Shingle

The next shingle is laid over the first with the edge just covering the glue strip on the first. Nail it with the roofing nails in the same way that you did the first.

Step 5 - Continue Installing Roof Cap

Using the same process as with the first two shingles, complete installing the roof cap in order to complete the roof.

Step 6 - Install Prefabricated Roof Cap

man installing roof cap

If you are using a long metal prefabricated roof cap you will need to use a different method. In some ways it is much easier. Start at one edge of the roof and lay the cap on the ridge line. Use foam insulation along the edge of the roof cap where it meets the metal roofing material. Remove the paper backing and stick it to the metal roof. Press the cap into the foam and drive in self-sealing screws along the edge of the roof cap.

Step 7 - Install Second Length of Roof Cap

Once the first section is secure you can install the next section. Slide the second section under the first by one to two inches. Install the foam insulation piece in the same way and secure the cap with self-sealing screws. Continue to install the roof cap in the same way until it is finished.