insulation problems


Old 06-11-01, 10:16 AM
Visiting Guest
Posts: n/a
We have a steep-sloped roof (cathedral ceiling) in which the insulation is nearly touching the roof greatly reducing air flow. This past winter we had major ice damns. The house is about 15 years old. It has continuous soffit vents and a ridge vent across the entire roof - but with such little air space (about 1") between the insulation and roof, reduced air flow. Is there anything that can be done to improve the air circulation to prevent ice dams in the future. Thanks.
Sponsored Links
Old 06-11-01, 01:42 PM
Visiting Guest
Posts: n/a
The lack of air flow is not what caused your ice damns, Ice damns are caused by heat loss. What occurs is the underside of the roof gets warm enough to melt the snow next to the shingles. This water ends up running down to the overhangs where there is not heat and then freezes. As more water runs down a damn is created and then the additional water coming down backs up undr the shingles. I would guess it is due to minimum insulation value. What is the R-value of the insulation.

I would guess you probably in addition have recessed lights in the ceiling. When these lights are installed in convential framed roof areas 2x8's 2x10' or 2x12's there is no insualtion installed above them...If they are not insualted cans then the insualtion is held back approx 3" from either side of the light fixture. Since heat rises there is a tremendous amount of heat loss in cathedral ceilings with this scenerio.

The ventilation is actually beneficial in the warm months,
this allows the hotter air to be carried away and eleminates a moisture build up between the underside of the roof deck and the insulation..

If you have these recessed lights, I would suggest you remove them and put in track lighting, and also install a ceiling fan near the top area to blow the warm air back down towards actuall living space....

Another cause of ice damns is when builders run bathroom exhast fans to a roof vent. This heat just blows up the underside of the attic ceiling and melts the snow like crazy creating isolated ice damns...

Good luck

Old 06-19-01, 12:38 PM
Visiting Guest
Posts: n/a
THanks for your response, unfortunately, I don't think it's going to help. I realize the melt is caused by heat loss-my thought was that with the insulation so close to the roof that that's where the problem is. Without the cold air circulating between the insulation and the roof the heat remains trapped and causes the melting. We have a good 14" of fiberglass insulation in the ceiling, no recessed lighting, and the bathroom vent is vented correctly on the other side of the house - far away from our ice damn problems, and we have a ceiling fan already. Any other thoughts?
Old 06-19-01, 06:34 PM
Visiting Guest
Posts: n/a
This one sure has me puzzeled.... Only other thought I can come up with is if your gable end of the studio ceiling is not insulated well, then perhaps you are losing heat through those areas and that is then transfering to the underside of the roof area... Apparently your able to see into the area, which makes me think you have an access hatch to some attic area... Is it well insulated above the hatch?

Other than that at the moment I am for a loss to give you any other suggestions~!!

Good Luck


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes