Home>Discussions>INSULATION & HVAC>How to Insulate an un-finished attic and prevent Ice-Dams in a 1920s 2-family home in Cold MA?
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V
How to Insulate an un-finished attic and prevent Ice-Dams in a 1920s 2-family home in Cold MA?
V

Hi everyone! 

I have a 1920s home with an unfinished attic here in snowey Massachusetts. The attic ceiling is un-insulated, with exposed 6" rafters and an asfault tile roof. I was warned about ice-dams and how impropper insulation will lead to a destroyed roof. The problem is I have no idea how to prevent ice-dams -- this is something new to me.

With the wisdom of the community, how can I set up my insulation propperly to prevent icedams?

  1. Is spray on closed-cell foam my best bet?
  2. Do i  need to cut soffit into the attic roofline?  Is there something else I should do
  3. Any other tips or tricks?

Thank you everyone in advance for the input! 

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V
Re: How to Insulate an un-finished attic and prevent Ice-Dams...
V

Would love to answer any questions! Looking for any insights from the community. 

V
Re: How to Insulate an un-finished attic and prevent Ice-Dams...
V

Humm, not too much activity in this forum :( 

 

Appreciate the opportunity to post :) 

Clarence
Re: How to Insulate an un-finished attic and prevent Ice-Dams...
Clarence

Try this site they have some very goog people to answer your questions. DIY CHATROOM

V
Re: How to Insulate an un-finished attic and prevent Ice-Dams...
V

Thanks Clarence! 

John
Re: How to Insulate an un-finished attic and prevent Ice-Dams...
John

Here is a This Old House video explaining ice damns.

How to Prevent Ice Dams

FRANCO
Re: How to Insulate an un-finished attic and prevent Ice-Dams...
FRANCO

Attic Fan or Insulation?

 

So in comparison, both options represent an improvement over the status quo but, when combined with a radiant barrier, the insulation is the better choice especially when you realize that the added insulation will also help reduce your winter heating costs. For my home the choice is clear but your home may be different. I recommend contacting your local home performance contractor with help in making your decision.

 

Robert
Re: How to Insulate an un-finished attic and prevent Ice-Dams...
Robert

Ice dams are caused by heat rising into the attic and melting the snow, which drains to the eave. Once the water is past the wall, it will refreeze at the overhang. As the ice accumulates, it will back up and force its way under the shingles where it can leak into the house.

You need to keep heat out of the attic by air sealing - VERY IMPORTANT! Then adding more insulation. I am partial to putting sprayfoam insulation in the rafters. Loose fill cellulose is another option.

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