Asked on Nov 23, 2013

How do I seal my basement windows from the inside?

Jeff C
by Jeff C
I discovered that my basement windows are leaking a large amount of cold air. There is also a lot of condensation on the inside of the windows. These are terrible basement windows and I want to know whats the best way to seal them shut. The basement is not a liveable space so I'm not concerned about escaping a fire. The basement is referred to as the dungeon for obvious reasons.
Terrible basement windows
Lots of condensation
Condensation that has rusted the metal frame of the windows
  34 answers
  • Debbie Harris Debbie Harris on Nov 23, 2013
    Silicone caulking
  • Jeff C Jeff C on Nov 23, 2013
    That's what I was thinking, clear silicone caulking.
  • Debbie Harris Debbie Harris on Nov 23, 2013
    Yep! That's the right stuff.
  • Energy Wise Mfg. Energy Wise Mfg. on Nov 24, 2013
    Here's (see actual photo) what a lady in Platteville did and it appears she had almost identical style windows in her basement. Interior double glazed interior storm windows from Energy Wise Mfg. 563-542-2134
  • Marie Marie on Nov 24, 2013
    Hello Jeff, If you don't mind how it looks you could make a wooden frame just a bit bigger than the basement window and stretch plastic over that and nail it over the inside of the basement window, it will be inexpensive as well. Hope this helps. Marie
  • Thelma Serna Thelma Serna on Nov 24, 2013
    Just heard about this the other day.....Thought it genius!!......Go get a large roll of bubble wrap...cut to size of your window......grab spray bottle of water mist window and put up bubble keeps out cold!!! hope this is good for was for me!!!!!
  • Jeff C Jeff C on Nov 24, 2013
    While that may help covering up the glass, I have air coming from around the window, the frame, and cracks in the concrete block itself. Ughh. Too much cold air being sucked into the house.
  • Lrc225795 Lrc225795 on Nov 25, 2013
    Replacement double pane windows installed correctly will stop the air. These are available from big box stores or companies which specialize in replacement doors and windows. They can have them manufactured to the right size and the installers are slick at installing quickly and do a good job (most of them). You will be pleased. A lower cost quick "get by" is to fasten boards on the wall around the window opening. Before fastening the boards to the wall, put plenty of caulk on the back side of the board which will go against the wall to seal out cold air. Then staple and/or tape heavy plastic from a hardware store or the bubble wrap.
  • Jeanette S Jeanette S on Nov 25, 2013
    We had all the windows replaced in our home a couple of years ago. We do save on the power bills, but the best thing is, we stay warm and cool with less energy. If your home is old, the best thing to do is replace these windows. You can find a good vendor who will work with you. In fact, we only deal with contractors with all the necessary insurances...including Workmens Comp...and we only did about 8 out of the 22 to start with so we could see their finished work and how the windows looked. We were very fortunate to find a great contractor!
  • Jimrusk Jimrusk on Nov 25, 2013
    Jeff if you can't afford to replace the windows yet, you will need to start by taking the trim off of the outside and seal it there first. Then re-install the trim boards (replace if damaged) That is where the condensation is coming in as well as the air. Use silicone on the outside and inside. You can then scrape off the drywall or what ever material they used in the basement to get to those areas from the inside to seal. You will want to clean the rust and mold out from those areas as the mold spores can travel through the air to the upstairs. Not healthy. I had to do this in my basement as well. Plus I had to caulk the bricks where they were cracking as it was letting moisture in and causing mold behind my drywall.
  • Helen Jenkins Helen Jenkins on Nov 25, 2013
    Maybe if you wire-brushed the wall around the window to remove loose particles and used clear plastic or bubble wrap and Gorilla taped it all around it might hold for the winter.
  • Elizabeth Elizabeth on Nov 25, 2013
    I would start with a good silicone seal and then use the 1" stryofoam type insulation board from Lowe's and cut to fit the window. It's amazing how much of the cold this will block out. We put the insulation boards in several of our north facing windows and it makes the rooms so much warmer. They will be darker but the savings and warmth will be worth it. Always put the foil side facing out. A large panel of this insulation board is less than $20.00. I think you will find it well worth it.
  • Diane Diane on Nov 25, 2013
    Please take into consideration SAFETY. What if you were in a situation that you needed to get out of the basement window in an emergency, will the sealing process prevent you from leaving the area?
    • Jeff C Jeff C on Nov 25, 2013
      @Diane As I mentioned in the post, safety is not an issue because it's not a living space. The only time someone is in the basement is when they are doing laundry. It's called a dungeon for a reason. Nobody wants to be downstairs.
  • Patti Patti on Nov 25, 2013
    I would go to Lowe's get a replacement thermal window since it is already weakened by moisture. until then if you do not want to lose the light take a matching size of plexi glass cut to fit add to outside and insid e of window. till then bubble wrap believe it or not really will help duct tape to inside and outside of window.
  • Jeff C Jeff C on Nov 25, 2013
    I'm just going to silicone caulk the hell out of every space I feel cold air infiltrating the house. Then, I'll apply the bubble wrap technique to the glass itself.
  • Pat Dollar Pat Dollar on Nov 25, 2013
    For a quick, low cost and temporary fix I would recommend a can of spray insulation which expands upon spraying. The cost would be around $15 and you can find it available at places like Lowe's or Home Depot.
    • Jeff C Jeff C on Nov 25, 2013
      @Pat Dollar Not sure how that would help? Where would the spray foam go? You can't spray it on a surface, it has to be within a cavity. It would create a big mess.
  • Pat Dollar Pat Dollar on Nov 25, 2013
    Jeff, You would spray it directly on the surfaces surrounding the window where the air leaks are. It does not have to be in a cavity to work. I looked up a reference for you:
    • Jeff C Jeff C on Nov 25, 2013
      @Pat Dollar well, after having used spray foam before, the only guarantee it provides is making a mess. Look at the pictures I posted, where would you put the spray foam?
  • Cheryl Knapp Cheryl Knapp on Nov 25, 2013
    having an old stone foundation and even after installing new windows we needed something; my husband used the spray insulation around the frame/stone areas and what a difference! And we can still open the windows with no problem.
  • Pat Dollar Pat Dollar on Nov 25, 2013
    The link I gave you will show how it is applied. I suggest you watch the video.
  • Jeff C Jeff C on Nov 25, 2013
    I did watch the video and every time it was used, it was to fill a void. There are no voids to fill around the windows except the window opening itself.
  • KAT KAT on Nov 25, 2013
    I just saw a post on FB that showed how to cut medium sized bubble wrap the shape of the window, spray the window with a mist of water and lay the bubble wrap bubble side to the window and they say it will stay until you pull it off... If it is resistant in sticking, then tape it around the edges... It makes sense and might be a temporary fix for this cold Winter we are having... My whole LOG HOME leaks since the logs have settled and this Winter I did 3M weather stripping tape all around the windows and doors... Next Summer hopefully re-chinking.
  • Deborah Slocum Deborah Slocum on Nov 25, 2013
    I have used the bubble wrap on my three season porch and it makes a world of difference. I put it on the windows, then covered in clean plastic over the frame. Made a huge difference!
  • Teresa A Teresa A on Nov 25, 2013
    I had deteriorated metal windows in a house that looked just like yours. Home Depot has DAP Latex expanding foam. I foamed around mine and I attached bubble wrap to the window. It worked quite well. I had used latex expanding foam because the window can still be opened. I measured the window opening and special ordered plastic block windows that had small built in screens. In the summer, my son and I used a hack saw and cut the old frames out and installed the replacements. It was an easy job at the right time of the year.
  • My opinion is to put up a sheet of Styrofoam from the hard ware store then seal around it (which is around the frame of the window with the foam. The foam will seal out the drafts and keep the Styrofoam piece in place so that your window is completely covered. If there was an emergency you could easily remove the Styrofoam.
  • Meredith Black Meredith Black on Nov 25, 2013
    I cover mine with plastic & it helps a lot.
  • Wolfe Art Wolfe Art on Nov 26, 2013
    Jeff, I don't think you understand how cold air leaks and condensation works. You don't have to have a cavity around the window for air to come through or in order to use the spray foam. What the spray foam will do is to stop the tiniest of leaks from passing air through. All you need is the smallest of air transfer for there to be a huge condensation issue. If you seal around the window with the spray foam it will stop the tiny air leaks, thus stopping the condensation, drafts and heat loss... or big air leaks, for that matter. I don't think he's suggesting you cover the entire window. If you use bubble wrap or styrofoam, you will still need to make sure it's a snug fit with no air leaks at all.
  • Ella H Ella H on Dec 12, 2013
    I have the same type of windows you have Jeff. I chalked around the side, put plastic bubble wrap over that and then two sided tape with plastic. /Made a big difference
  • Diane Johnson Diane Johnson on Dec 12, 2013
    I would put together a simple wood frame to the interior size, put bubble wrap on the window and use the frame (Stapled with 4-6 mil plastic on it) on the opening-finish with spray foam to seal the edges. Tape the entire frame including the inside wall edge.
  • Jennifer Jennifer on Dec 14, 2013
    @Jeff C this stuff really does work I used it on a leak in my basement... give it a try, I believe they sell it in stores now Good Luck :)
  • Cathy Conley Cathy Conley on Sep 13, 2014
    @Jeff C I think that if you ask for suggestions, you should be thankful for the people that took the time to try to help, not argue with them. A simple thank you and if you don't want to use their idea, then don't.
  • Kathryn Denny Kathryn Denny on Sep 01, 2016
    Along with all these good ideas get some basement window bubbles from any hardware store they are not expensive and work well and are easy to attach
  • Becky P Becky P on Sep 09, 2016
    OMG we have windows that look just like that. Ours leak when the gutters overflow. So he took out the glass, and siliconed really good, so hopefully they won't leak anymore.
    • See 1 previous
    • Becky P Becky P on Oct 29, 2016
      He usually does. Esp when we are expecting a storm. We just have a stupid tree in the neighbors yard that likes to drop leaves/walnuts all over the place.
  • 62q10370829 62q10370829 on Sep 11, 2016
    I have the same trouble but no window sweat. I have rain coming In on bottom . Thanks for the idea
  • Barbara Barbara on Nov 07, 2016
    They are now insuch bad condition, It best to just replace them with new or glass block and your problem is resolved. They have been left to rot and rust too long to repair