Raising detached garage in Florida

[MarcDob]

Looking for words of wisdom. I have to raise a detached garage or tear it down and build a new one above flood level.

Just bought a house on an acre this year. My goal is to finish one of my 3 outbuildings with double wall construction for music rehearsal with drums. I do not really need advice on soundproofing, I'm planning on double wall 'room inside room' construction with 2 leafs of 2 layers of 5/8" drywall and green glue. Neighbors are not to close. This construction should provide enough of STC (sound transmission loss).

I knew there was a chance this building would flood during heavy rain and hurricane Milton brought 4 to 6 inches of water in. I was planning to start construction next week BUT ain't no way I should start putting up layers of drywall I won't be able to reach after the next flash flood event.

As is it's:
- 24 x 26, 2x4 frame building.
- on slab
- plywood and vinyl exterior.
- not finished inside at all.
- metal roof
- 1 man door, 2 windows and one roll up car door.
- solar water panels that heat my pool are on the roof which I'll take to down for a lift

I've got a basic idea from YouTube videos and a thread on this forum of what it's gonna take.

What I do not know at the moment is if I go for a permit to raise the building onto a concrete pony wall is it I'll likely get turned down.

I'm thinking I should consult with a concrete contractor before contacting permitting for my county.

If you have any advice I'm listening. I've already read all thru SparkyNutz Wet Garage Raise and. watched his and other YouTube videos

 

[john.k]

Why get turned down?........after the big flood here in 2011...the state govt and city council actually required owners to raise buildings above flood level ...and paid for a lot of the house raising.........some houses were raised 15 feet and more.

 

[Stuart in MN]

How much will you have to raise the building?

 

[MarcDob]

How much will you have to raise the building?

I estimate needing to raise my building by 3-4 feet to be safe. FEMA guidelines suggest a minimum of 12 inches above the 100-year floodplain, but I'll need a water engineer to confirm the exact elevation. Given my recent flooding of 4-6 inches, I anticipate the engineer recommending at least a 2-foot lift.

The additional height from raising the building will provide an unexpected benefit due to my soundproofing design. With a current ceiling height of 8 feet 3 inches, I planned to add two layers of drywall to the trusses, a 1-inch gap, 2x6 inner ceiling joists, another two layers of drywall and finish the floor. This would reduce the ceiling height to 7 feet 6 inches, meeting my sound isolation goals but creating a somewhat cramped space.

However, raising the building by an additional foot or two would significantly improve my audio mixing environment.

 

[Danno1]

.

I would prefer the concrete stemwall up here, but don't you have to use stilts down there so the floodwaters flow under the building? As opposed to bearing on a wall.

.

 

[cvairwerks]

I'd stop by the building department and simply query them about the question first. A lot of them are willing to be much more helpful with guidance when you come in asking before taking action. Building in a hurricane zone is where getting your questions answered befoe committing things to paper is much cheaper than having to redo things.

 

[CraigStu]

cvairworks has the idea. I have done that twice on 2 different garage addition projects. I took our lot plat, a few pics, and a tablet w/ me and chatted for 20-30 minutes. One in Md and one in Va. I did make appointments ahead of time. In Va they had electrical, framing, and ground work people. But they had one guy who could do all 3 and he is the one I talked with.

 

[Professor Fate]

You may find out that in Florida you can have no net increase of fill in a flood zone. That means that you will have to take fill from one location on your property to add fill to another. Standard is one load in, one load out.