Ask the Builder: Inspector can help assess shingle failure
DEAR TIM: A powerful rain and wind storm damaged the asphalt shingles on my home. My neighbors are telling me I need a new roof. I think it can be repaired.
The wind blew off a few shingles here and there. The roof is only 3 years old, so I don’t feel it’s an age issue.
I realize you can’t inspect my roof, but can you tell me if it’s hard to replace a shingle or two and how one might do it? What might have caused the shingles to blow off? What should I look for up on the roof to make an evaluation if the roof needs to be replaced? – Jeremy W., Raleigh, North Carolina
DEAR JEREMY: Mother Nature bats last indeed. This past weekend I was in a cemetery, and my attention for a moment was drawn to a tiny mausoleum. It was made of solid stone, including the roof. Each side of the roof consisted of three large slabs of thick overlapping stone. I grinned thinking how the designer wanted a roof that will stand the test of time, but even those solid stone slabs will succumb to the effects of weather.
Shingles can be made from many materials, including wood, metal or thin pieces of overlapping stone (e.g., slate). But far and away the most popular material in the North America is asphalt shingles. The reason is they’re easier to apply, they’re relatively inexpensive and, when installed correctly, they can last decades depending on the slope of the roof.
It’s hard for me to speculate what might have caused your shingles to blow off. One thing is certain: The wind was able to get up under the shingles that are now on the ground. Once the underside of the shingles is exposed to the wind, the lifting and tearing force can easily defeat the roofing nails that hold the shingles in place.
Modern shingles come with a self-sealing asphalt cement designed to interlock the bottom of each shingle with the one below it. If the missing shingles are on a steep north-facing side of your roof, it’s possible this sealing compound never got to activate as well as it should have.
When the sun’s rays hit shingles, it heats them up, causing the self-sealing compound to activate. In most situations, this compound does a magnificent job of welding the shingles together.
The roofing nails that held in the missing shingle or shingles may have not held well for a host of reasons. Maybe the nails were not long enough. If you can gain access to the attic space below the roof where the shingles are missing, inspect the roof sheathing to see if it’s rotten, has cracks or is soft.
While your neighbors may have great intentions, I’d ask at least two independent home inspectors to come out and give you an opinion. If you tell them you just want them to look at the roof, you could get a significant discount on the fee. Calling in roofers for this consultation might not be the best idea, as some of them will have a bias in favor of recommending a new roof. There are ethical roofers who will tell you the truth, but you need to make sure they’re the ones putting the ladder up against your gutter to go up and inspect.
If you decide all is well with your existing roof and you have the courage and confidence to get up on the roof, you can replace the missing shingles with relative ease. It’s all a matter of making sure you don’t fall from the roof. Do whatever you have to do to be completely safe. I could write a book about fall protection, but that’s not what this column is about.
If you look at the written instructions on how to install the shingles that are on your roof, you’ll quickly discover it’s a matter of overlapping one shingle over another and creating a staggered layout so the butt seams don’t lay on top of one another. You also must use the proper length nail, it must have the approved galvanized coating, and it must have the proper shaped head.
Be sure you remove any of the old nails that are probably still sticking into the roof sheathing. You do not want to place the new shingles on top of nails that could puncture the new shingles!
The nails must be placed in a specific region in each shingle. The instructions will show you where. Don’t deviate from these instructions.
Eventually you’ll have to slide a new shingle up and under a row that’s still attached firmly to the roof deck. To do this, you may have to remove the nails of the row of shingles directly above the shingle you’re installing as well as the next row up from that. This is where many rookies stumble because they don’t realize that nails from shingles above penetrate the shingles below them in several places.