Raised Floor Insulation in Savannah, GA

Raised floor insulation is for houses with open air underneath: cottages on brick piers, island homes on pilings, and older houses whose crawl space walls never closed in. On Tybee Island, Wilmington Island, Isle of Hope and other low ground around Savannah, raising a house above flood level is common. The space under the floor is effectively outdoors, so the floor itself has to be the insulated, air-sealed boundary of the house.

Why batts fail under raised homes

Fiberglass batts held up with wire or netting are the old standard under raised floors. Wind moves right through them, humidity soaks into them, and they sag or fall within a few years, especially after a storm. Animals nest in them. When we look under raised homes, fallen batts and gaps at the edges are the most common thing we find.

Closed-cell foam on the subfloor

Closed-cell spray foam sprayed directly onto the underside of the subfloor and the joist sides seals the floor against wind and humid air and adds R-value in the same pass. At roughly R-5 to R-7 per inch, two to three inches meets the Department of Energy's R-13 suggestion for Zone 2 floors. It also helps keep ducts and plumbing under the floor out of the outside air when they run between joists.

Flood zones

Many raised homes here are in mapped flood zones. FEMA's 2025 Technical Bulletin 2 lists closed-cell foam as an acceptable flood damage-resistant material, while open-cell foam, cellulose and other absorbent insulation are rated unacceptable. That makes closed cell the only spray foam we use below the flood elevation. We ask for your flood zone and elevation certificate if you have one.

Protecting the foam

Under a house on pilings, foam is exposed to sunlight and weather at the edges, and some homeowners want it covered. We can talk through coverings, and where the space under the house is used for storage or parking, local rules on enclosures and breakaway walls apply, so we keep our work to the floor assembly.

Plumbing and ducts

Pipes and ducts hanging below the joists stay outside the foam layer. We note them on the quote, since they may need their own insulation or rerouting, and we keep access to cleanouts and valves. Get a free estimate