How long tile lasts
HUD's useful-life table for capital needs assessments plans clay or concrete tile at 60 years. The underlayment beneath the tile is a separate layer, and the only way to reach it is to lift the tile; ask what the quote does with it.
A single leak on a roof with years of life left is usually a repair.
Tile can't be roofed over
Florida's existing-building code requires a tear-off to the deck where the existing covering is "wood shake, slate, clay, cement or asbestos-cement tile," and also where the roof has two or more layers or is water-soaked or deteriorated (FBC Existing Building 706.3). A new covering never goes on top of tile.
Product approval and Broward's HVHZ
Florida requires approved roofing products. In the High-Velocity Hurricane Zone, which in the area this site covers means Broward County, the code is explicit: "All roofing components, roofing systems and roofing assemblies shall have a valid and current product approval" (FBC Building § 1512.2.1). In the HVHZ the contractor also goes through a required owner's notification with you, item by item, and you initial it (§ 1524). Ask for the product approval numbers of the tile and of the system that fastens it.
A house permitted before March 1, 2002
On a site-built single-family house permitted before the Florida Building Code took effect, a full roof replacement must also include a secondary water barrier and re-nailing of the roof deck (Fla. Stat. § 553.844(3); FBC Existing Building 706.7). For a house in the wind-borne debris region with an insured or appraised value of $300,000 or more, roof-to-wall connections are improved too, up to 15 percent of the cost of reroofing (§ 553.844(3)(b); 706.8). These are lines on the quote; ask to see them.
The 25 percent rule
If more than 25 percent of a tile roof or roof section is redone within 12 months, the whole roof or section has to meet the current code, unless it was built or replaced under the 2007 Florida Building Code or later (FBC Existing Building 706.1.1; Fla. Stat. § 553.844(5)).
Weight
Tile is heavy. Switching to tile on a house built for shingles is a framing question; switching from tile to a lighter covering is not. Ask the contractor what the framing was designed for.
What changes the price
Concrete against clay or another covering; tear-off and disposal; deck re-nailing and the secondary water barrier on older houses; the approved assembly; hips, ridges and penetrations. More on the Florida rules: replacing a roof in Florida. Every Florida place on this site lists its own share of homes built before 2000: start from Florida.
Questions
How long does a tile roof last in Florida?
HUD’s useful-life table plans clay or concrete tile at 60 years. The underlayment beneath the tile is a separate layer that can only be reached by lifting the tile, so ask what the quote does with it.
Can a new roof go over tile?
No. Florida’s existing-building code requires a tear-off to the deck where the covering is clay, cement or asbestos-cement tile (FBC Existing Building 706.3), so a new covering never goes on top of tile.
Can I replace a tile roof with a lighter material?
Switching from tile to a lighter covering is not a framing question, while switching to tile on a house built for shingles is. Ask the contractor what the framing was designed for.
What should a Florida tile roof quote show?
Ask for the product approval numbers of the tile and of the system that fastens it. On a site-built single-family house permitted before March 1, 2002, the quote should also show the secondary water barrier and deck re-nailing.