Thread: Piers

Just got back from a great vacation in Florida. It's snowing again today in Ontario.

Out of curiosity, we were wondering how those new houses on the tall piers stay up during a hurricane? Did not see any with cross bracing, etc to resist side loads. We were in the area Charley hit and didn't see any on the ground, so apparently they are good enough. Looks odd though.

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I thought most had cross bracing in coastal areas, the ones without just have less height, lots more piers and the depth into the ground is probably more.

Originally Posted by David Wood

Just Out of curiosity, we were wondering how those new houses on the tall piers stay up during a hurricane? Did not see any with cross bracing, etc to resist side loads.

We were in the area Charley hit and didn't see any on the ground, so apparently they are good enough. Looks odd though.

David,

I broke your post up into to parts for this reason:

- "new houses " as in new

- "Charley" as in Hurricane Charley

Hurricane Charley was in 2004, so there would be lots of "new houses", none of which have 'been tested' by a hurricane.

Not having seen those you are referring to, but having seen others in other areas (like the Keys), the main failure point is the hinge joint at the top of the pilings and the platform the house is on, with the second main failure point being inadequate embedment.

While cross bracing, knee braces, etc., are one way to stabilize the structure, another way I've seen them done is to use long enough pilings to extend up to the roof structure, thereby eliminating the hinge joint at the house platform and using the structure's walls as bracing for the pilings.

Several different ways to design those things, and some work better in some areas than others do, in other areas, about any method will work ... until the wind blows or the water moves in around the pilings.

It's not just the wind, it's also scour from water moving around the pilings.