There are several measures by which roofers will be measured and some are more obvious than others. In fact, there are some defects that can occur when shingles are being installed that are so obvious, that even non professionals can easily spot them. We’ll discuss these shortly. There are proper ways to install shingles and most people do not know it all starts with the length and positioning of nails when completing a roofing job.
The length of the nail matters
Depending on the type of weather that can typically be expected in the location of the building where the roof is being installed, a roofer will consider the length of the nails used to attach the shingles to the sheathing. In fact, there are some less than honest roofers that will purposely use shorter nails because the local building code may allow them to and because these nails are more likely to fail the roof in the event of a strong storm. This means that the owner of the house or building where the shingles are being applied will be more likely to call that roofer for repair work. While this is not one hundred percent the case in all roofing installations, this shady practice can work in the advantage of the roofer that is looking to capitalize on their clients and poor weather.
If ½” sheathing is used, you typically want to make sure that 1 and ¼ “ nails are used to ensure that they fully penetrate the shingles and sheathing below, otherwise only the tip of the nail, if anything, will show. This means that the shingles may be more likely to bend or curl or even detach from the sheathing all together in a strong wind.
Roofers also know that most home inspectors will not walk along the roof or thoroughly inspect the attic. The reason a good inspector would want to look in the attic when it comes to verifying the quality of the roof install on the house is to look for those penetrating nails in the sheathing that is the ceiling in the attic. It’s the easiest way to quickly tell whether the correct length of nail was used when that roof was installed.
Positioning matters too
Most roofing contractors will know better than to allow shoddy nail positioning and will usually fix this issue if they notice one of their employees not positioning the nails correctly. This is because even non professionals know that the heads of nails should not be seen simply by looking at the roof. If you can see the nails, you know that the roofer didn’t install the shingles properly.
First, the head of the nail should be overlapped by the shingle above it, covering it from the elements and making it not visible unless the shingle above is peeled back to expose it. Second, there is a narrow band on each shingle where the nail should be driven to ensure that it catches not only the shingle being installed, but also the top of the one below it.
Watch for these and other common roofing installation mistakes
As we’ve seen, the nail that is used as well as its positioning is important to a good and proper install of new shingles. Having said this, there are still other mistakes to consider and watch for as well:
1. As discussed, improper nail length and positioning
2. Overdriven or underdriven nails
3. Misused vent types and mixed ventilation
4. Misused or forgotten underlayments
5. Re-using (or not using) flashings
6. Improper install or missing drop edge
7. Installing new shingles on old or rotted boards
While these are some great examples of items to look for to ensure a proper roof install, they’re only a few of the things you should watch for. Each and every one can affect the quality of the installation itself, and if not properly installed (or simply not installed) from the beginning could lead to issues with the roof down the road that the homeowner will end up having to pay for.
A reputable roofing company will not only allow, but welcome a homeowner to inspect their work during and after the install, explaining each step and giving honest answers as to why they’re recommending what they recommend. They will also ask for your input on several steps to make sure that you’re completely satisfied with the work that is done at the end of the job. Be weary of a contractor that shy’s away from this type of interaction and question what they’re using to install your roof. It’s an investment that you want to ensure is properly installed from the beginning so you get the maximum life out of it.