Ask the Builder: Roofing 101: Tips for an expert installation

I have no clue how many new roofs are installed in the U.S. each year, but it’s got to be in the hundreds of thousands. Perhaps a new roof is in your future or in the next few years. If so, you’d be wise to read up on the topic at askthebuilder.com before it’s time for you to meet with a roofer.

Most roofs installed in the U.S. are asphalt shingles. The reasons are many, but for the most part, asphalt is easy to install and affordable. The issue is the asphalt shingles of today are nothing like the ones that were manufactured even 40 years ago.

I exposed the shortcomings five years ago in my book “Roofing Ripoff.” You might want to read it. It will absolutely put your head on a swivel as to all things asphalt shingle. I discovered while writing the book how to make asphalt shingles last 40, or more, years. It’s all in the book.

If you’re like most homeowners, you wring your hands worrying about leaks. It’s a valid concern! Understand the vast majority of roof leaks on the average home almost always are at a flashing. Rarely does a leak form in the giant open field of shingles.

A flashing is a transitional material that connects your roof to something that’s not a roof. Here’s a short list of where you’d find flashings:

• Chimneys

• Dormers

• Plumbing vent pipes

• Skylights

• Any other vent that is popping up through the roof to expel air from your home

There’s a common plumbing vent-pipe flashing many roofers use that has a rubber boot attached to an aluminum flashing base. The issue is after 10 years or so, the ultraviolet rays from the sun cause the rubber to crack and split where it touches the plumbing vent pipe. Water can enter here.

I’ve discovered a better plumbing vent pipe flashing made from powder-coated steel and it has a special siliconized-rubber boot. My guess is from my own testing, it might last 50 or more years. It’s made by Lifetime Tool. I have a video at askthebuilder.com showing exactly how to install a plumbing vent flashing. I urge you to watch it.

You’d do well to educate yourself using different books, shingle manufacturer’s installation instructions and even some YouTube videos about how flashings should be installed. Once you grasp this somewhat simple topic, you’ll know the right questions to ask the roofers who are bidding for your job.

Don’t even think of using caulk on a roof to help seal joints in flashings. Caulk is not a permanent roofing material. Once again, it’s also very susceptible to damage from UV rays.

Flashings should be made from metal that you can solder. Copper is an excellent flashing material. Tin used to be used for decades, but stringent EPA regulations have all but killed the tin market. Talk to your roofer about flashing materials that can be soldered.

As for skylight flashings, I’ve had the best luck with Velux. They have pre-engineered aluminum flashing kits. The base and head flashings for the bottom and top of the skylight don’t require any soldering. I’ve installed them on countless jobs and have these on my own home and have never had a leak.

The nails that are used to fasten your roof to your home are extremely important. Once again, read the written installation instructions from the shingles you decide to use. See what nails they require so that you maintain your warranty.

Pay attention to the length of the nail and how far it must penetrate the wood roof deck. Hot-dipped galvanized nails are the best. The roofer who installed the shingles on my New Hampshire house (I didn’t build the house) used nails with a thin electroplating of zinc.

When I re-roofed my home six years ago, many of the nails I was taking off were heavily rusted. They were only 11 years old! The nails you use should last longer than the actual roofing material.

You might wonder about underlayments or water shields. I happen to live in the Northeast, where ice dams are common. Ice dams can form at any location on a roof, although most do form down at the bottom of a roof where the roof passes over the exterior wall of the home.

I decided for the ultimate peace of mind to install Grace Ice and Water Shield over my entire roof. I lapped it up on the sides of my skylights and connected it to my plumbing vent pipes, as well. You can’t see any of this, as it’s all hidden by the other flashings that cover these roof penetrations. I now don’t have to worry at all about dreadful leaks caused by ice dams.

My best advice is for you to select the roofing material you’re going to use. Do this before talking with any roofer. Once you’ve made your decision, get the full set of written installation instructions from the roofing manufacturer. Read them.

You’ll quickly discover the instructions are easy to follow and understand. Once you understand how your roof should be installed, you can ask the right questions when talking with roofers. Be sure you put in your contract with the roofer that he’s to install the roof exactly as the instructions say. Period.

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