Cleaning Up Bad Spray Foam Installation
Hi! I recently purchases a home which was originally converted from an old barn, its a beautiful building, but the basement underwent a very very messy retrofit with spray foam by the previous owner. The ceiling which is old 100 year old thick beams / joists has been filled with gray yellow spray foam between the joists in a very messy way that looks just terrible. I plan to make this space into a workshop that I will spend considerable time in, and want to clean it up. What tools might I use to remove the spray foam from the wood, and what protection would be appropriate? I was hoping to try out using an angle grinder with a wire brush attachment and a sawmill with a flexible long blade attachment and see if either of those worked. Based on some forum or other I tried a “Curry Comb” but this is not suitable to the amount of foam I need to remove. What type of respiratory protection do I need to do this? I was thinking I would try a 3M full face mask with P100 filters? Any advice? I have been scouring the web for advice and coming up empty. Thanks in advance! -N
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Not sure what type of foam is gray. Perhaps it's closed cell foam that's been painted? I found a wrecking bar works well. You swing it so the short end wedges between the foam and the plywood. You can then pry it and usually pop a chunk off. For the remain bits, you can scrape those with a thin bladed bar such as a jiffy bar. It's a lot of work and it will be difficult to remove all of the remnants. Make sure you wear eye protection.
Sorry about that I meant to type “spray foam” not “gray foam” (I edited the post)… that’s for the suggestion of using a wrecking bar!
Why not just cover it? You could remove it from the beams where necessary and cover the rest with drywall. Way less time and effort and keeps the insulation value. If you're set on removal, it's going to be a bear of a job. The flat bar method works OK, but if the foam is thick and well adhered you probably won't be able to pop it loose. OTOH, it's probably not stuck all that well to the dirt surface of the old lumber. You won't know until you try. Otherwise, a sawzall will work, but you'd have to be very careful about buried pipes and wires. Breathing protection is more for nuisance dust than anything actually toxic. An N95 disposable mask would probably be fine if it fits well. A full face mask with P95/N95 cartridges would give you eye and breathing protection, but those are darn uncomfortable after just a little while. I generally do OK with a half-face respirator and goggles. YMMV.
Thank you! This is what I was gravitating toward, the more I read about spray foam the more I worry about ingesting the dust... even though after its cured its inert, it appears that heat from grinding could release fumes and just plain breathing the inert dust not so great either.
I want to leave the beams / joists exposed both because I think they are beautiful (100 year old construction!) and also because the space already has low ceilings and adding a ceiling to the bottom the beams would make it feel even lower. BUT I could potentially cut panels of drywall or plywood to size and fit them up between the beams. A little tricky but it could work.
But to cover it up will still require that I remove it from the sides of the beams. Do you think I would be Ok using a wirebrush on a grinder for that if I use tyvek suit and half respirator? I tried starting this process with a curry comb and its WAY too time consuming, I just did a few feet in 15mins. I'm hoping that if I hit the beams / joists with the wire brush it won't generate enough heat to melt the foam and would just create dust and I would be safe with some sort of mask?
Some photos attached, sorry the photos are terrible, they were not taken for this purpose but I just found some photos that happened to show the ceiling.
Certainly, installing a ceiling across the bottom of the joists would be easiest, esp. if they are reasonably flush across the bottoms. You'd only lose 1/2" of headroom..... I do understand that the space would feel smaller without the spaces between joists.
To remove the foam from just the sides of the joists, you might try a simple handsaw (maybe a "keyhole" drywall saw) and/or long, sharp knives. The stuff is not all that tough. You could carve away most of it by hand in a hurry, then have at it with a wire brush to clean off the residue. I wouldn't worry about the dust all that much - a half-face respirator and eye protection should be fine. I see rails for a garage door in one of those photos. If you can open the space up and get outside ventilation you're even in better shape.
Thank you! Your 100% correct that the actual headroom lost would be very little, but it would feel a lot lower, because of loosing the space between the joists.
I have a full face respirator mast so I'm thinking if I wear that with the 3M P100 2091 particulate filters I should be safe.
There is also a rollup garage door, so I can put a fan there for ventilation, although I don't really want to blow lots of toxic dust particles out into the dirt and gravel outside :)
Thank you for your advice!
-N
That looks like a pretty typical spray foam installation. I think you'll find it will be a LOT of work trying to remove all of that, especially where it's around things like pipes and wires. I would use wide scrapers, driving them between the foam and the structure and working to pop off chunks. This will cut down on dut. A sawzall will help too, but remember that there will probably be services (electrical/pipes/etc.) buried in the foam, so your sawzall could easily cut right through important things that you can't see.
I'd strongly recommend just covering things and not trying to remove the foam.
Bill
We often suffer from the carelessness of previous homeowners. I recently moved into a house where the previous owner had never repaired the roof. He didn't seal the holes in the roof. He just covered them with mounting foam. Can you imagine my surprise level when he said that his roof was in perfect condition? I'm amazed by his arrogance. I've been putting this house in good condition for about six months. I did a complete renovation under the roof and replaced the wallpaper in the rooms on all floors. After that, I decided that I needed to do general cleaning. I used the services of this company https://crowncleaners.org.uk/end-of-tenancy-cleaning/brixton since I liked the reviews on their website. They did a great job! After visiting these specialists, my house was perfectly clean.
We often suffer from the carelessness of previous homeowners. I recently moved into a house where the previous owner had never repaired the roof. He didn't seal the holes in the roof. He just covered them with mounting foam. Can you imagine my surprise level when he said that his roof was in perfect condition? I'm amazed by his arrogance. I've been putting this house in good condition for about six months. I did a complete renovation under the roof and replaced the wallpaper in the rooms on all floors. After that, I decided that I needed to do general cleaning. I used the services of this company https://crowncleaners.org.uk/end-of-tenancy-cleaning/brixton since I liked the reviews on their website. They did a great job! After visiting these specialists, my house was perfectly clean.
njencks: I STRONGLY urge you to delay doing this. Why?
First, it is alot of work. You might have your heart set on this now, but ultimately you are talking about a basement workshop. Any time you spend on this takes away time from your family and from the projects you would accomplish in your workshop. Time that you will never get back. Look at this again in a year and it may not be where you want to spend your time.
Second, you many not accomplish what you intend. The typical recommendation is to make the crawl or basement a conditioned space, so the spray foam goes around the outer perimeter foundation walls, you need to figure out why they did it different in this case. You need to live through at least one full year of seasons, and hopefully at least one big storm to find out what that basement is like and why they did not encapsulate at the perimeter.
Third, you will have unintended consequences - once you remove the spray foam, if you do a good enough job, you now have a new project, which is insulating and air sealing your living space above, because, you know, you just removed everything that was insulating and air sealing it.
I totally get that the spray foam encroaches on the space and may make it feel smaller than it is. However, you would be astounded how much a good lighting plan and reflective paint changes the feel of a space. I would select a few areas where the underside of the joists are NOT already encapsulated, and put up a bright reflective white sheet, perhaps with some recessed LED's penetrating the sheet, and see how that makes that one area feel. My guess is much better than even open bays of framing with the spray foam removed, and it also makes it easier to control dust.
+1 with CL. The garage door suggests your basement is a 'relatively unconditioned' space. That foam is stiffening your floor, likely reducing board squeaks, and who knows what else. I'd live with it for a year and then see if it's still the highest priority.
If you don't know the best way to clean off old foam, cut off the top layer of the mixture with a knife, and then apply warm sunflower oil. That's what we did when we moved into a new house with a renovation. We had new windows installed, but the foam was still there. Then we decided to call https://gotenancycleaning.com to have all the surfaces in the house cleaned so as not to ruin the new fresh renovation. The method of cleaning depends on the type of material. If you pick the wrong bottle, you will be left with stains. So I don't recommend doing it yourself.