[rdarvish]

I am in process of finishing my basement. I have done the 2x4 16" o.c. framing, electrical, A/C duct , and etc. I was ready to start insullation today but after reading several threads here I stopped because I am so confused. Here is my situation:

I biuld my house in northern VA 16 years ago with out finishing the basement. The basement walls are poured 8" solid concrete. The basement is inground on three sides and walk -out on one side with mainly large windows and entery door to outside. When I built it all the upper half of the in-ground sides were insullated by fiberglass and coverd by aluminum foil attached to the wall. The walk out side used the same method but on entire wall. I have inspected the fiberglass attached to the in-grounst walls and the are dry with no sign of miosture where touch the wall. The is no sign of dampness or water leak on the walls. I noticed some codensation on the walk -out side exposed to outside air. But I am not sure it is water or the lubricant from the concrete forms.

I bought R-13 Owen Cornning fiber glass bat with paper on one side and the packege says for basement. I was planning to install the fiberglass along the entire height of the wall with paper side in-ward and then cover the entire wall with 6 mill vapor barrier before installing the dry wall. Howevere, after reading the threads in here I am real confuse.

I am now concerned if I proceed as I planned I would face with mold issues as sson as I close the walls and ceilings. Here are my questions:

1- Do I proceed as I plan?
2- Do I ripe off the Aluminum foil from the upper half and install new insulation with paper barrier against the wall?
3- Do I leave the existing insulation with foil cover inplace and install new insulation on the lower half of the wall?
4- Do I install plain fiberglass insulation in the frame cavities.
5- Do I get rid of the existing and new insulation and have insullation componies to spray foam insullation directly to the face of concrete walls?
6- or somthing completly different.

I appreciate the help in advance.

 

[Bob Mariani]

# 5 is the best solution. The vapor barrier (plastic) should not be used anywhere. Water moisture problems occur after insulating and sealing the walls, so even if dry now, it means very little. Walls are to be treated differently for the above ground and below ground walls.

 

[rdarvish]

Basement Insullation

Bob, thank you for quick response.

Just to be clear, If I hire an insulation compony to spray liquid foam directly to walls do I still need to insullate the framing cavities with paperless fiberglass?

How about the walkout wall that is not in-ground.? do I treat it the same?

Thanks

 

[Bob Mariani]

you can use the faced batts in areas above ground to save money. Closed cell spray will control the moisture issues and offer better insulation in the below ground wall areas.

 

[Gary in WA]

Don't forget to spray the rim joist (floor) areas. Be safe, G

 

[Bob Mariani]

agreed.. 20% loss at that area and fiber glass batts just will not due for the rim joists. (area above the concrete foundation wall)

 

[rdarvish]

Basement wall Isulation soooooo confused

Well, price was around $2000 for 2" application of spry foam materials for DIY. in my area the contractor probably charge about $3000.

Since I have 1"-6" space behind my framing I thought to buy 1" x 4' x 8' styrofoam sheets and glue them to the concret wall and add unface fiberglass to the othere side. Would that work? this is much cheeper.

Do I need to leave an gap any where?

Thanks

 

[Bob Mariani]

The foam board on the concrete is fine. Even 1" will do. Then the air space and then the wall with batt insulation. Yes this will work and be cheaper.

 

[rdarvish]

Basement wall Isulation soooooo confused

Bob:

Appreciate your help.