How Much Should Roofing Felt Overlap

Adjacent pieces of drip edge should overlap at least 2 inches 51 mm.

How much should roofing felt overlap.

Nail along the top of this strip at 500mm. If this felt is either incorrectly situated i e. Roofing felt is required to overlap 2 inches over the lower felt course. Take your second length of felt.

Must be installed at the rakes and eaves of the roof. Where the sheets overlap apply roofing sheet adhesive using a disposable brush. Purchase an extra pack of felt in case you need more or end up damaging your first roll. Make sure you have enough roof felt you don t want to have to stop mid way through the project to buy more felt.

Position this strip so that it overhangs the top of the first sheet by 75mm. The overlap of 3 8 should be followed consistently for a smooth look once the shingles are installed. The drip edge should extend at least 2 inches on the roof. Therefore a 2 inch overlap provides redundancy at the edges where the barrier is weakest.

Trapped behind the guttering or if it is badly weathered it needs to be replaced. However you must allow for overlaps on joints. Ensure that the felt lies flat and smooth before securing it. The vertical leg of the drip edge should be at least 1 5 inches wide and extend at least 0 25 inches below the sheathing.

The felt must be flush at the rake side edges have 4 inch overlaps where two pieces are joined and 6 inch overlaps on hips and ridges. Tack the roofing felt down with 1 4 staples using an air compressor with a pneumatic stapler a hammer tacker or a staple gun every 12 inches. The bottom course of felt on a roof called sarking felt ensures that all of the rainwater is correctly channeled into the gutter by protecting the eaves from any wind driven rain. In other words if the height of the roof drops by 2 inches for every 12 inches in length you will need to use sealant to strengthen the overlap barrier.

Work up the roof to the peak and fold felt over the top overlapping at least 3 inches and fasten it on both sides. The overlapping felt creates a secondary barrier for moisture and wicks water away from the shingles above and the sheathing below. Do the other side of the roof the same way also with an overlap at the peak. If lap sealant is used simply apply a bead of sealant on top of the underlap ridge going all the way down the length of the ridge before the overlap ridge of the next panel is placed on top.

A conventional roll of felt is enough for 432 square feet. One roll of conventional 15 felt covers 432 square feet 40 1 m 2. Some roofing felts are actually glued down. In most cases this will leave 400 square feet 37 m 2 of net coverage per 1 roll.