Fiberglass roof shingles are the most common type of shingles sold. Under most circumstances they’ll do a good job of protecting a roof for many years. Installing fibreglass roof shingles is a job most people can undertake, although it’s important to follow all the steps for a tight, secure roof.
Step 1 - Preparation
Before putting on new fiberglass shingles, check the roof. It needs to be level. None of the dips in the plywood should be more than ¼ inch. There should be a gap of around 1/8 inch between the plywood panels to allow for expansion and contraction. Having good attic ventilation can also extend the life of your fiberglass shingles.
Step 2 - Extra Security
Check all the flashing, including the boots around vents, to see if it needs to be replaced. Put in a new metal drip edge on the roof and install an ice shield. This stops ice and water being pushed into the area under the lowest shingles, which can cause water damage.
Step 3 - Felt
Before adding shingles, it’s important to put down a layer of roofing felt. To install this, start at the bottom of the roof and roll out horizontally. The layers going upward need to overlap the ones below it by 2 inches. Where a roll runs out, have the new one overlap the end by 4 inches. At the peak of the roof you’ll use felt going over the top. It needs to overlap the horizontal rows by at least 6 inches on each side.
Step 4 - Shingles
With all those items in place, it’s time to begin laying the fiberglass shingles. The first row you install will be at the bottom of the roof, over the drip edge. This row requires special attention. With the utility knife and metal square, cut the shingles across at the top of the cutouts. This gives you a much small shingle. Put this on the drip edge and nail down, using 4 nails per shingle. Only this row needs to be cut this way.
Step 5 - Chalk Lines
Before putting on more tiles you’ll need a pair of chalk lines to ensure they’re properly placed. The horizontal line needs to go across the strip of fiberglass shingles you’ve put in, and the vertical line goes from the bottom to the peak at the inside edge of the lowest shingle. This offers a guide for alternating odd rows of shingle. After this, nail the second row of shingles in place, making sure you use ample nails – 4 per shingle.
Step 6 - Higher Rows
Now add another vertical line that marks the inner edge of the second row of shingles. This will be your guide for alternating even rows of shingles.
Step 7 - Ridge
Nail shingles in place all the way to the peak. You’ll then need to install fiberglass ridge shingles over the peak, which will overlap these shingles. To finish, trim the tiles where they overlap the edges of the roof.