This is a great post that clearly summarizes the different options for changing a roof; what's allowed by law and the difference the amount of nails per shingle can make in a storm situation.
Time to Replace Your Roof?
It’s almost spring and time to do some house repairs. One of the things a homeowner will need to this spring do this check is the condition of their roof.
One of the first things to do is to hire a licensed and insured/bonded roof contractor. Make sure they pull a permit from the city in which you live. To forgo this step can be costly to the homeowner. It may even more costly to the home owner who has a mortgage who require a windstorm inspection certificate.
Once upon a time you could hire an engineer who would literally count the nails in the roof make some calculations and issue a certificate. In some areas you may you may still be able to do this. What we have seen in our area is engineers who don’t want to take the responsiblility to do this after the fact. I think it’s about the insurance.
Make sure you ask around to see who has hired which roofing companies to replace their roofs. Ask what them what liked about the company they chose and who they hired and did they do a good jobs and if they would hire them again.
Once a permit from the city has been pulled; a permit will be placed in the window of the home for the inspector to see. The inspector will come out and inspect the home to see that the work was done according to code. When the work is done a green tag will be placed indicating that the roof passed inspection. A red tag is not a good sign.
You need to note that if you already have two layers of shingles on your roof; they will all have to be torn off before a new roof can be replaced, this is a code requirement.
If you have two layers of shingles the contractor will go on the roof tear off the old shingles and inspect the wooden decking to see if any of the sheets of ply wood need replaced. If there are some that need replacing they will be done.
In a full roof replacement the company will then lay down overlapping layers of "felt paper", which is a black thick tar looking paper starting at the bottom of the roof’s edge and work to the top. Once all the felt paper is nailed onto the roof then they will start placing the asphalt shingles on the roof. Once the roofer puts about half of the shingles on, it is time to call the inspector for the second inspection to see if the correct number of nails are being used.
Now you have to know if you will need a 4-nail shingle or a 6-nail shingle. What is the difference? The difference is where you live. Some cities requires a 6-nail shingle because of the coastal proximity and the hurricanes that come into the Gulf. Hurricane winds can come in and rip off a 4-nailed shingle where a 6-nail shingle will better withstand the high wind velocity.
I have been told by some inspectors that during a hurricane event some homes in cities who had used the 4-nailed shingle lost their roofs. While homes across the street in another subdivision did not because of the 6-nailed shingles used in the course of building the homes. I would suggest that once all this work is complete I would keep a copy of the permit and the inspector’s signature approving the work performed on your home. This is an important paper that should be stored with other important papers should you ever decide to sell your home