Basement Insulation Question

[Bobsy]

I am in the process of renovating my basement and have read conflicting stories on how to insulate the exterior walls.
I have framed the walls with 2 x 4 studding and was planning to insulate right down to the floor plate.
However, I read on another site to stop the insulation 8" above the floor and continue the vapour barrier 2'' past the insulation.
Any opinions on the proper method.
Thanks in advance.

[J.P. Rap]

I am in the process of renovating my basement and have read conflicting stories on how to insulate the exterior walls.
I have framed the walls with 2 x 4 studding and was planning to insulate right down to the floor plate.
However, I read on another site to stop the insulation 8" above the floor and continue the vapour barrier 2'' past the insulation.
Any opinions on the proper method.
Thanks in advance.

Yep...Lots of opinions here. We had a similar discusion a while back and got the same conflicting suggestions and more.

The CHMC website (http://www.cmhc-schl.gc.ca/en/search/search_001.cfm) is a good place to start looking.

Here (http://www.canadianwoodworking.com/forum/showthread.php?t=12248&highlight=basement+insulation) is one of the earlier threads on the subject.
HTH

[Chris in Saskatoon]

I haven't checked personally, but according to my father around here if you use fiberglass batt insulation the city wants you to run vapour barrier against the concrete, then down under the bottom stud plate and back up around on the inside.

Basically you end up with a regular insulated stud wall in a plastic bag.

Chris

[J.P. Rap]

I haven't checked personally, but according to my father around here if you use fiberglass batt insulation the city wants you to run vapour barrier against the concrete, then down under the bottom stud plate and back up around on the inside.

Basically you end up with a regular insulated stud wall in a plastic bag.

Chris
Actually, I believe it's from ground level down, around the bottom of the wall and back up to the top on the inside.
IIRC.

[Chris in Saskatoon]

Actually, I believe it's from ground level down, around the bottom of the wall and back up to the top on the inside.
IIRC.

Not around here...but I forgot to mention that they want you to slash the plastic above ground level. Presumably to allow moisture to escape.

Chris

[Andrew in Ayr]

The best way is to glue 2" rigid styrofoam right to the concrete wall, from floor to ceiling. No vapour barrier necessary. Then frame your 2x4 wall in front of that (can use 2x3's to cut down on space).

This is fairly expensive though. I am in the process if finishing part of my basement right now. The builder had already framed and insulated the exterior walls; I didn't find it necessary to remove and re-do all that. It was done fairly well. Felt paper was nailed to the concrete, then framed up with 2x4's, insulated floor to ceiling with fiberglass batts and vapour barrier.

Roxul is a good product to use in basements because of moisture issues. I really hate working with the stuff though, however I did use it on all partition walls and the ceiling for sound control.

[Ron Evers, Beeton, ON]

Just been through this with our sons new house, a raised bungalow. Bottom half of the wall is poured concrete , the upper 2x6 studs. The walls were then framed inside with 2x6 floor to ceiling with heavy poly between the floor & bottom plate. The inspector insisted that the concrete be covered by asphalt felt or house wrap (after we had the 5½" batts installed). Down came the insulation & house wrap fished between the concrete & the studs & fastened along the sill plate. The outside stud wall was insulated with 5½" batts, the inside wall the same from the floor up to overlap the outside insulation & then all covered with poly.

This may be confusing but in the end we have the concrete covered with house wrap (printed side to concrete) then R-20 batts then poly. The upper part of the wall has R-20 batts between the outside studs, then an air gap between the inside studs & then poly.

[J.P. Rap]

Not around here...but I forgot to mention that they want you to slash the plastic above ground level. Presumably to allow moisture to escape.

Chris

Yep, That's the idea. Same thing done a different way.
I don't see the point of installing a VB if your just going to slash it. But if that's what they want you to do then that's what ya gotta do.

[Spokeshaven]

From my experience, there is no harm in taking both the insulation and vapour barrier all the way to the floor when below ground level. There might be debate as to what it will help with, but there as certainly no harm.

As to slahsing the vapour barrier, or wrapping it around the studs inside and out (forming a bag around the insulation), both seem absolutely nuts to me and contradict the whole reasin for installing vapour barrier.

This site might have some more general info for you. (http://www.cwc.ca/design/building_science/internal_barriers/vapour.php)