I recently purchased a home and have begun to do renovations on the basement. I am starting to look at insulation and so I have been researching what the best way would be to do that. The problem I am having is that the house was built in the 70s and has no moisture barrier between the cement wall and the studs. What are my options for insulating? Is there a way to install moisture barrier with the wall frame still up? I’m dreading the work and money it will cost if I have to remove the framing to redo this insulation.

As a note, the house has been around 50 years without a moisture barrier, what are the benefits of putting one in now if there have been no moisture issues for close to 50 years?


  • I wouldn't consider adding insulation without an inorganic vapor barrier against the foundation wall. Even if there hasn't been leaking inside the basement, there almost certainly is moisture that is seeping through (unless your basement is in death valley) and adding organic material to somewhere with moisture means you will just be creating a mold problem to deal with later. Also, have you tested the basement for mold? There may be some mold on the drywall already which would make the decision to rip out and start fresh that much easier to make. – statueuphemism Apr 20 '19 at 14:07

Have you looked into closed cell spray foam? It forms its own moisture barrier as well as being a great way to insulate. No need to remove any framing as it will cover all areas and seal them.


There are any number of paint-on moisture barriers. They are available on-line or at the big box stores, paint stores and hardware stores. They each come with their own list of references. Good luck.

  • Thanks for the reply! I suspect with these paints I would have to make sure I get in behind the studs in any event? I will have to make sure there is space in behind all of them – Matthew Amell Feb 8 '19 at 1:27

If you looking to add vapour barrier to improve your building envelope then spray foam is your best choice. If your goal is to protect the framing from future water damage then you need a water proofing membrane. That would require installation of a weeping system underground with a sump pump. After all any water making it to the inside wall has to go somewhere.

If your concern is the former keep in mind that a vapour barrier goes on the internal part of a wall just behind the drywall or other surface finishes. A typical sequence of construction would be framing, mechanical(some mechanical is allowed outside the envelope), electrical, insulation and then vapour barrier. Spray foam will take care of the last two steps in one fell swoop and do a better job of it most of the time. But it will not stop water from leaking in from the foundation or water table.

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