Part 3 of our 7 part series of articles explaining the roof deck attachment section on the wind mitigation form. Section 3 of the form has to do with the roof deck attachment. The roof deck is also known as the roof sheathing which is usually Plywood, OSB or Dimensional lumber.
What are the requirements to get the roof deck attachment discount?
For a home to get the discount on the wind mitigation form it must have a minimum of 8D nails. The spacing should be every 8″ to code but there is an option for every 12″ on the form also. When you look at the discount breakdown for insurance carriers there doesn’t seem to be any difference between the two but every carrier is different. If you have a dimensional lumber roof deck then you need 2 nails per board or 1 if the board is 6″ or less. The contractor can also use approved screws & adhesives that have and uplift resistance of 55psf but we rarely find those in the field.
When were the current requirements put in place.
If a roof is installed now it must be fastened with 8D nails spaced every 6″. For new homes that was put into place when the current FBC took place on 3/1/2002. If you have an older home and had a new roof installed it was put into place on 10/01/2007. There are parts of Florida where certain jurisdictions required the use of nails before 2002. If you have a roof that was installed later than 2010 and your roof wasn’t re-nailed chances are it was done by the cheapest company available and without a permit.
What type of attachment was used before 8D nails?
Most older homes before the current FBC came out had decks that were attached with staples or smaller nails such as 6d. If these are the only forms of attachment then the house will not qualify for the discount. When a new roof is installed the contractor will go along and add 8d nails to bring it up to code.
If you would like to see if your house qualifies for this discount you schedule your wind mitigation inspection with us at 407-633-1661 or book online.