During an arctic blast last winter, one of our tenants sprayed the sills and channels around every (wooden) window in her apartment with expandable "great stuff" insulating foam in order to "cut down on draftiness."

You guessed it! Now that we are being hit by our first spell of really hot weather, she calls and suddenly informs us that none of her window sashes can be raised or lowered.

I just got back from evaluating this nightmare and trying to free them up with a butcher knife. While I was able to slice and cut out much of the ever expanding and bulbous stuff, I still can't raise the sashes in any of the windows.

A guy at Lowes said the best next step would be to contact the makers of "great stuff" to find out what, if any, kind of liquid might exist that would melt and loosen up the bond between this stuff and surfaces.

If you have any experience or ideas on how to solve this nerve wracking problem, please send them to me before I go nuts. MANY MANY thankyous

Smaller knife and a smarter tenant.

First of all I'd let your genius of a tenant live with it for this summer. But be sure to get the price of new windows and charge them for it.

Go to Amazon and search for: sash paint saw

That foam is going to creep in everywhere. Unless you get 100% out you will be fighting it down the road with changes in weather.

And only way to do that is to remove sashes.

I would not put much time and money in old windows. Sounds like as good as time as any for replacement windows.

Get a price for removing sashes and cleaning the foam out.

Will not be cheap since they may have to damage some of the track getting them out.

I second Landlord of the Flies.

You might also give her the option of calling YOU chosen window replacement people so she can arrange and pay for the work. Getting the price might wake her up to the extent of the damage she did. (Or get the quote & show it to her). Can this tenant come up with that kind of money?

My tenant did the same thing but used super glue to keep the window from leaking air. If she only told me I could have replaced the sash and insulation so the top double hung window would have stayed up. All she had to do is lift the upper window and latch it closed.

So I remove the window and replace it with a duel gaze window, stand size 36" wide x 48" tall.

You could try an oscillating multi tool, but I'm thinking the foam has expanded into areas you wont be able to reach.

I think that is a new one for me. Sometimes tenants are very good at doing the un-imaginable.

Sawing with a fine saw to get in the spaces is the way to go, but the stuff expands and oozes into spaces you will not be able to get a saw into and probably won't be able to get anything in to dissolve it. Acetone will dissolve it, but it will be a mess and you will probably have to ventilate well (hard to do when the window won't open) and wear a respirator.

I believe acetone is what Great Stuff says will clean up spray foam. But I don’t think you will be able to get it into enough joints to move those windows.