When you DIY spray foam insulation, be prepared for mishaps where the foam sprayed in place doesn’t quite turn out the way you had hoped.
Maybe the spray foam layer is not as thick in some areas as you wanted, or you accidentally got foam on the concrete floor or other surfaces where you didn’t want it.
If this happens, don’t despair! You can still fix it.
Ways to Get Spray Foam Off Concrete
First off, note that the removal process differs for cured and uncured spray foam. Here’s how it works.
Uncured Foam
If the spray foam hasn’t cured yet, you’re in luck. It’s much easier to remove uncured foam than cured foam. You can use one of the following solvents to remove spray foam.
- Rubbing Alcohol: While it’s the least effective method, it works for small spills. Use 91% isopropyl alcohol, and blot the area with a clean rag. Let the alcohol sit for a few seconds and wipe clean.
- Acetone: Acetone is more effective than rubbing alcohol, but it’s also more likely to damage surfaces. When using acetone, apply it to a rag and then wipe the area. You may need to do this several times to remove all traces of the foam. Don’t use acetone near any plastic surfaces such as piping or containers to avoid dissolving.
- WD40: Use a WD40 spray to cover the spray foam you want to remove. Wipe the spray off with a towel or rag. Repeat if required.
- Commercial Foam Removers: You can also buy a foam remover, such as the PENOSIL Premium foam remover, to get rid of uncured spray foam.
Cured Foam
If the spray foam is already dry, prepare for some elbow grease. You’ll need a utility knife to cut the foam and a strong solvent to remove the residue.
Start by cutting away as much foam as possible with a utility knife. Make sure to cut as close to the surface as possible to get an even layer off.
Once only a thin layer of spray foam insulation is left on the concrete, moisten the surface with a dissolvent. You can use one of the solutions listed above.
Leave the dissolvent on the concrete surface for 10 minutes. Then, use a stiff cloth or sponge to rub the area and remove the foam. Repeat the process if necessary to remove all traces of spray foam insulation.
How to Remove Closed-Cell Spray Foam From Concrete?
Closed-cell spray foam is denser and more rigid than open-cell spray foam. Thus, it’s more difficult to remove from concrete and other surfaces.
The best way to remove closed-cell spray foam from concrete is to use a chisel and hammer. Start by chiseling away as much of the foam as you can.
After chiseling away most of the foam, use a hammer to break up the remaining pieces. Sweep or vacuum up the debris and dispose of it properly.
You can also use a dissolvent to remove any residue or thin layers you can’t scrape off with a knife. If you get any spray foam on your hand, use a nail polish remover or acetone to remove it.
Or, you can put petroleum jelly on your hands and cover them with latex gloves for about two hours. Wash your hands with soap and water to remove the petroleum jelly.
To avoid spray foam getting on your hands, use personal protective equipment (PPE) when performing any work with spray foam.
