Hurricane Resistant Homes – Part 5 HOUSE GEOMETRY
The geometry of the house. When I say this I mean is it one or 2 or 3 (townhouse) stories and is it hip or gable ended roof and does it have anything particularly susceptible to uplift.
As one goes up in height the wind gets stronger so generally a single story house is better than 2 or 3 stories. This is due to the ‘shielding’ effect of ground structures, trees and the like.
The gable, hip or flat roof is the shape of the house. Hip shaped roofs tend to do better than gable shapes at the end walls and both do better than flat roofs. One can retrofit braces into a gabled roof end and these work well.
Most houses are a combination of at least 2 of these shapes but again if the house was built under the 2001+ FBC then it is built to withstand the appropriate loading. Many older ‘classic Florida’ homes have hip shaped roofs with flat screened rooms. These have been shown to be a particular weak point in many older homes. Wind gets under those screened patios and lift the roof up which can tear right off at the wall attachment point allowing water to get into the house and the damage can compromise the remainder of the roof. Now, I happen to like my big screened patio but I am very ware that it is a weak point in my house. And, I get less of an insurance mitigation discount because more than 10% of my total roof perimeter is something other than a hip shaped roof.