Recent hurricanes
After seeing how two hurricanes have devastated west and central Florida, I, a residential architect in Miami, once again recommend a concrete slab roof and reinforced concrete block for your new property or addition.
Why do I recommend this? It’s very simple. Concrete and concrete blocks are very wind resistant. With all the hurricanes Florida and the rest of the Southeast have been going through lately, it’s time these areas give up their traditional methods of construction – wood walls and roof structure.
Wood walls and trusses can be designed to withstand hurricane-force winds, but the connections need to be perfect. And this is the problem. If the workers of your general contractor were tired that day, or weren’t paying attention, then the connections may be imperfect.
Strength of concrete for a concrete slab roof in Miami
Concrete, on the other hand, is more forgiving. Since it is poured as a liquid, when it hardens it is almost indestructible. The way we build in South Florida is by putting a #5 steel bar every 2’-8” or so in a grouted cell. This bar must go from the footing to the concrete tie beam above. (See drawing below) So, as you will see if you build this wall, it is very hard and almost immovable.
Now, let’s compare concrete walls and concrete roofs to wood. Concrete can get wet. Nothing will happen to it. So even if you lose your roofing membrane in a storm, you may get a small leak into your house, but nothing like what will happen if you lose your roofing membrane and your shingles or tile roofing. And, if your roof sheathing is damaged, as I saw often after Hurricane Andrew, it would literally rain in your house.
Downside of wood structures
Over time, you may have damage to your wood studs and your roof trusses. Termites could eat them, or with any kind of water filtration, the wood could rot.
So concrete and concrete blocks may cost a little more upfront, but it will give you back rich rewards over time. Not to mention, you will be much safer during a hurricane.
Building concrete slab roofs
Not anyone can build a concrete slab roof or a concrete floor slab. You need a professional team. You will need an architect to design your house or addition, but you will also need a structural engineer to design the reinforcing for the concrete slab. And the best floor slab is a floating slab. In this drawing below, you see how the wall does not stop on top of the floor slab, but rather, bypasses it down to the footing. With this kind of footing, it is much harder to get cracking in the floor slab because the slab “floats” and there is no pressure from the wall on it.
Contact information
So, if you are interested in building a different kind of house with a concrete slab roof anywhere in the southeast United States, but particularly, in Miami, and you want it built correctly, call me, Maria Luisa Castellanos, R.A., a Miami residential architect with offices in Coral Gables. Call me on my cell phone, 305-439-7898 or email me at MLC@UnitedArchs.com