The Difference in Building Codes - The ABC Standard

There has been a lot of discussion about finding a contractor who will do a thorough job replacing a tile roof, following the hurricane damage. Even though Florida State Building Codes include consideration for hurricane strength wind, some contractors are focused on completing roof replacements to Miami/Dade County Building Codes with stricter requirements.

Due to Miami/Dade County’s rigorous standards, homeowners whose roof is replaced with Miami/Dade County Code standards may experience less damage should another hurricane hit the area.

Below are some differences in how a contractor will replace a roof with Miami/Dade County restrictions in mind, and suggestions to discuss with a potential contractor before having your roof replaced.

1. Apply for the permit and submit all applicable Notices of Acceptance on the products to be installed on the roof. Your local Building Inspectors won’t allow just any products to be installed on a roof. Proof must be submitted that the products a contractor plans to use have been tested to show they are able to withstand the sometimes intense South Florida weather conditions.

2. Remove the existing roof system to the plywood deck and re-nail the deck to meet current building code. A problem-free roof needs to start with a solid, well-attached wood deck. It should be checked for damage from any previous leaking and any needed repairs should be made at this time.

3. Install a peel & stick water barrier directly to the deck at the valleys, roof-to-wall connections and other especially vulnerable areas of the roof. These are the areas where roofs tend to leak in extreme conditions. An additional barrier in these openings goes a long way in preventing future problems.

4. Install the 30# base sheet according to Miami/Dade specifications; 240 tin tags per 100 square feet using 1 3/4” ring-shank nails. Underlayments are only effective if they remain firmly adhered to the roof deck. Wide tin tags installed securely and in abundance is the best way to accomplish a firmly adhered roof deck.

5. Prime and set all valley metal, vents, plumbing stacks and other flashings in mastic sealant. By setting these thin metal flashings in a mastic sealant you can prevent wind-driven rain from getting under the edges and leaking into your home.

6. Install drip edge and bird stops per Miami/Dade specifications nailing 4” on-center. It’s an unpleasant reality in Florida that if a roof isn’t properly sealed, pests like birds, bats, squirrels and rats can and will find their way in eventually. These barriers must be installed and secured correctly to keep these unwanted house guests from setting up shop in your attic.

7. Install a self-adhering modified bituminous underlayment sheet which is specifically designed for foam set application of the tiles and is Miami/Dade approved; like TU Plus or TU Max. Well installed, quality underlayments are the key to a leak free tile roof. The tiles look pretty, but the underlayments are what keep your home dry.

8. Install metal in the hip and ridge areas per Miami/Dade code. Metal ‘hat-channel’ must be installed under the hip and ridge shingles in order to secure them in place and prevent slippage and displacement.

9. Mechanically fasten the first row of tiles and set all tiles in a low-rise foam adhesive (like AH-160). Florida code requires that tile installed on roofs be securely fastened so loose tiles don’t become missiles in hurricane-force winds. Setting the tiles in a foam adhesive is one of the most effective ways to accomplish this.

10. Tuck point all hip and ridge shingles with mortar. This final step not only helps to secure the tiles but it is also another important part of preventing pest infiltration. Having a roof replaced in Collier & Lee County to the standards set by Miami/Dade County may help mitigate future loss in the event another hurricane strikes. When selecting a contractor we advise asking about their experience with installing roofs to Miami/Dade County Code requirements.