Roof Flashing Repair: 3 Mistakes to Avoid

Roof flashing on a red roof.
What You'll Need
Roofing nails
Caulking gun
Flashing sheets
Asphalt flashing cement
Metal shearers
Possibly a ladder

One common issue with roofing maintenance is the replacement or repair of what is called roof flashing, or simple flashing. Roof flashing is sheet metal installed at any breaks, joints, or edges on your roof to prevent leaks. Most flashing is composed of aluminum or galvanized metal. This means that roof flashing repair can typically be cheap and easy to do, although there are some mistakes to avoid.

If your roof is at the point where you need to repair or replace flashing, you first want to identify what pieces you will be repairing or replacing: step flashing, vent flashing, or chimney flashing. Then, you want to gather the tools and materials you’ll need.

1. Doing Nothing

There are some things you want to avoid doing when it comes to roof flashing. The first is waiting. You also do not want to repair your entire roof. But doing the repairs yourself when the need first appears will save you a bundle of money, and lots of headaches later on. Water that leaks into your home is an invitation to many other problems. It can lead to rotted wood, mold, and mildew forming in the walls and ceilings of your home. Before your small leaking roof problem turns into a home nightmare, get it repaired.

2. Being Careless

Use a safety harness or a spotter to avoid falls. Always be aware of where you’re standing on the roof, and don’t get careless. Wait for good weather or for rainy weather to clear up and the roof to dry off before attempting to repair it. Your roof might be slippery from the rain. Check the weather forecast for thunderstorms nearby. Don’t take any chances.

3. Doing a Sloppy Job

Do not rush the job, unless the weather is turning worse. If it is, your best bet is to simply use tar and cement to temporarily seal the cracks. Otherwise, take your time and do it right.

Repair Types

There are three different types of roof flashing repair. Step flashing is when you repair the damage by putting in new flashing over the damaged area. First, snip the new flashing with your shearers, then bend it to a 90-degree angle. Then slide it up the roof, preferably on top of the damaged flashing. Adhere it using your flashing cement.

Vent Flashing is damage near or on the vents of your roof. First, locate the leak. If the problem is with the pipe itself, you should replace it with a new collar or install a larger collar over the existing pipe. For more severe damage, you may need to install all new vent flashing, which requires removing the shingles and replacing each piece again. Your roofing nails will be used up quickly if this is the case. Make sure you have enough.

Chimney flashing repairs are done around the chimney area. If the damage and the leak are minor, you should be able to replace the chimney flashing just like you would step flashing. If the mortar joint is deteriorating, the joint will need to be repointed and you may need to have this done professionally. Either way, the damaged area will need to be cleaned with steel wool or the flashing cement will need to be used to finish the job.