Low-slope additions and Florida rooms
Walk any 1960s street in Largo, St. Petersburg or New Port Richey and you will see the same thing repeatedly: a main roof at a shallow pitch, and attached to it a Florida room, carport or lanai cover that is essentially flat. That addition is a different roof, and it needs a different material.
- 1 Ridge caps. Full sun, no shade, ever. They cook before anything else on the roof does.
- 2 The field. Shingle, or tile sitting on felt that is doing the actual waterproofing.
- 3 Valleys. Two slopes emptying through one line, every single afternoon.
- 4 Flashing. The metal salt air finds long before it touches the covering.
- 5 The vent boot. Rubber baked brittle by sun, and the bay area’s most ordinary leak.
- 6 Eaves. Where the Florida room ties in, and where the hardware corrodes first.
Where shingle stops working
Asphalt shingles shed water by overlapping. They work because water runs downhill fast enough not to find its way under the courses. Below roughly a 3-in-12 pitch that stops being true, and manufacturers say so in their own installation instructions. A genuinely low-slope section needs a continuous surface instead: a rolled or modified bitumen membrane, or single-ply. When someone puts shingle on a Florida room because it matches the house, they have installed a leak with a delivery date.
The second failure point is the junction. The addition meets the main house at a wall, and the water shedding off the main roof arrives right at that seam. Flashing there has to be done deliberately, and on additions built decades ago by whoever was available it frequently was not.
What to insist on
When you gather quotes on a house with an addition, establish three things before comparing numbers. Is the low-slope section included in the price at all, or is the quote only for the main field? What material is specified for it? And how does that material tie into the main roof at the wall? A bid noticeably below the others on this housing has, in most cases, simply left the addition out, and that is the part most likely to be leaking.
Want this looked at?
Call (866) 227-2038Say what you have noticed and you will be connected with a provider covering your county.