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re use builders insulation blanket or not?

Posted: Mon Feb 11, 2019 10:30 am
by lariviere
Hi Shannon,

Just found your site, thank you for all the great information. I’m currently finishing my basement and have some questions about insulating. I currently have builder installed blanket insulation four feet down, then bare concrete. My plan was to remove the blanket and use 2” rigid foam from floor to ceiling. The rim joists are already sealed with batts and accustic sealed ploy. Would I be ok to leave the rim joist as is, or should I remove and seal with rigid foam? It was also suggested to me that I could leave the bag in place and frame against it. Then just add batts and drywall. I’m not sure I’m comfortable with that approach though. I would appreciate your advice.
Thank you.

Re: Rim Joist Insulation With Different Method Using Rigid Board

Posted: Mon Feb 11, 2019 10:53 am
by lariviere
Forgot to mention I’m in Windsor, so milder winters and humid summers. Would it be appropriate to not go all the way to the floor in case of basement flooding? I see a lot of people stopping about foot off the floor.
Thanks again.

Re: Rim Joist Insulation With Different Method Using Rigid Board

Posted: Mon Feb 11, 2019 8:22 pm
by Shannon
Welcome ! For sure remove the builders blanket, you don’t want to re use it.
Install your foam and seal it just like my video. Then frame the wall and insulate it as well. Some areas will allow you to skip the air/vapour barrier when you use 2” foam but that is something you should check at your local permit office. I would recommend using one but use one of the new types that will change as the conditions change.
If the hoist ends are done and sealed they will be fine left alone.
I have never understood why some people have recommended leaving insulation up off the floor. There are other options you could use for the bottom foot or so and that would be more rigid foam incase you get flooded.