How To Seal Roof Vent Flashing

Of course you don t want cement oozing all over your roof but you do want to ensure a strong seal.

How to seal roof vent flashing.

Then do the same thing with another piece of tape on the upslope side of the pipe. Roof shingle over step flashing. Use special masonry caulk to seal the joints between the flashing and the chimney. Identify the edge where your vent or in some cases metal flashing meets your roof.

The most common is to use roof caulking. A lot of roofers use roofing cement to seal the bottom of the flashing boot s pan to the shingles. Remove the nails that hold the vent pipe flashing to the roof. When applying the cement you want to apply a very liberal quantity.

Insert the putty knife under the corner of the flashing where it is nailed to the roof to protect the shingles. How to seal a plumbing vent pipe on the roof 1. Try to get all of the air bubbles out of the tape and press it firmly into the shingle the pipe and the underlayment. Purchase the cement in a tube that will fit your caulk gun.

Bend the corner flashing tightly around the corner. If you do not wish to form your own corner flashing you can buy pre bent pieces and cut them to size or use a piece of corrugated aluminum which is easier to bend. Renew flashing seals by chipping out the old mortar and caulking along the edges of the flashing. Roofing nails per side photo 2.

As you lift the shingles apply the cement to the back of the shingle about six inches in. This old house general contractor tom silva shows how to create a watertight seal around a vent pipe. Step flashing on roof peak. 1 remove nails holding down shingles above the pip.

Seal the seam between the cap and step flashing with urethane roofing cement or silicone caulking compound as shown at right. Put one nail in the bottom edge with a dab of caulk under it to seal the hole. There is no need to remove existing sealant unless it is already peeling off or there is an excessive amount of sealant already there. Rubber vent flashing automatically adjusts to any pitch lift the vent enough to spread caulk under the sides but not the bottom edge then nail with three 1 1 4 in.