What the F is the correct way to insulate a finished basement?

[kthroyer]

I am also in the middle of finishing my basement. I went through the same research headaches, and came to the same conclusion as Skoorb. I am using the exact same construction method as he shows in his pictures. The foam board allows some airflow between it and the concrete wall to allow for moisture to evaporate. This is the way Mike Holmes does it on his shows, he even uses it on basement floors.

 

[Modelworks]

Take a trip to your cities building permits office. It varies with where you live and they usually have a handout or diagram that they can show you how it is supposed to be done.


The cans of spray foam will work just like the big machines, just a smaller version. Good for around pipes and wires. Some of it will change color if exposed to sunlight but that doesn't hurt its effectiveness.

 

[spaceman]

thats best left to pink panther
and owens corning expertise

 

[totalnoob]

Just get a $30 rotating space heater and save yourself the trouble of insulating everything. Considering the cost in time and money, you can probably run the heater constantly for 20 winters before the electric bills overtake the cost of an insulation job.

 

[Booty]

I am also in the middle of finishing my basement. I went through the same research headaches, and came to the same conclusion as Skoorb. I am using the exact same construction method as he shows in his pictures. The foam board allows some airflow between it and the concrete wall to allow for moisture to evaporate. This is the way Mike Holmes does it on his shows, he even uses it on basement floors.

I was going to do this when I eventually finish my basement, but a recent storm brought in about an inch of standing water. It's the only time we've had water down there, and it was because so much rain came down so fast (we've had a week straight of storms previously and there was no issue with water/flooding)... but, of course, it could happen again at any time so it really put a damper on my finishing plans - especially because I don't know the primary source of the leak(s). Never lost power, so the sump pump kept going... I think it was coming in at the bottom of the walls...

Anyway, not to hijack the thread, but any of you have any experience with this issue?

 

[Vette73]

Yep my walls looked like Skoorbs. I used Dow stuff but same principle.

 

[PingSpike]

Ok, I looked at the wall last night and I'm thinking of yanking and reinstalling. With a little sawsall action I could avoid having to do anything to the adjacent interior walls. It'd be a pain in the ass, but it sounds like my drywalling crew is going to be delayed for a couple weeks now.

Those concrete nails are going to be a bitch though....

What kind of glue do you need to stick the XPS panels together?

 

[vi edit]

What kind of glue do you need to stick the XPS panels together?

I've always foamed the seams and then used tyvek tape over the joints. To stick it to the wall use a foam board adhesive.

 

[PingSpike]

Ok, brag time. It took me all god damn weekend, but I pulled all the framing on the wall, put the pink foam XPS insulation in, reframed the wall 2" out and replaced the bottom with pressure treated with a foam capillary break under it. And redid the wiring I undid. I also only injured myself once the whole weekend, a new record for projects.

For future reference, is there a clean way to cut foam boards? I didn't have a table to break them over after scoring them so I ended up sawing them which made a pretty big mess. No big deal.

As I was doing this job it occurred to me my previous lazy plan of just cutting pieces and jamming them in between the wall frames would have likely taken almost as long in addition to being wrong and sucking so I'm happy with my decision to waste an entire weekend on this.

 

[vi edit]

I used a circular saw to cut all mine. But they do score pretty easily to break...long ways. The stuff I used (DOW pink board) had some sort of stranding to the foam and it wouldn't score at all running across the board. It would bind up and it was impossible to make a clean line. A jig or circular saw fixed that. Mountains of pink foam shavings will be flying everywhere though.

 

[Modelworks]

You can clean cut it with a hot knife. A commercial wire cutter is really expensive but I know people that took a cheap kitchen knife, got it real hot under a blow torch and it slices through the foam like butter.
Also you can use a cheap $5 soldering iron for trimming around outlets, etc. Works well for cutting as long as the foam isn't too thick.



http://www.hsgmusa.com/pc_product_detail.asp?p_key=93CDD282E0994188A344EBAEF4A6A281&cat_id=

 

[alkemyst]

yellow pages.

 

[Homerboy]

yellow pages.

sweat equity

 

[Homerboy]

You can clean cut it with a hot knife. A commercial wire cutter is really expensive but I know people that took a cheap kitchen knife, got it real hot under a blow torch and it slices through the foam like butter.
Also you can use a cheap $5 soldering iron for trimming around outlets, etc. Works well for cutting as long as the foam isn't too thick.



http://www.hsgmusa.com/pc_product_detail.asp?p_key=93CDD282E0994188A344EBAEF4A6A281&cat_id=

http://www.instructables.com/id/Hot-wire-foam-cutter/

 

[PingSpike]

Heh, I guess using a hand saw wasn't to far off. Heat cutting seems like more trouble than its worth, unless I was doing a ton at once.

 

[Imp]

Very useful info. I'm looking into buying soon, and a "requirement" will be having a basement furnished/furnishable to rent out. I took a building science course in my final year of engineering, so should know how to do this properly, but forgot most of it. Still got the textbook, so ya. Long story short, there are calculations relating to air temperature, interface temperature, humidity, etc. You should be able to find trouble sports (i.e. condensation) through calculations.