Attic Insulation in South facing home

[LADYHAWKE]

Looking for some advice on adding insulation to my South facing colonial in NH. the house is new construction (3yrs old) with a walk up attic that has two dormered windows facing south. The attic floor already has R30. We will eventually convert this to a living space. In the winter, the roof tends to keep snow on the back side, and we get long icicles from the eaves on the backside. I believe this is due to the attic heating up due to the warmth of the sun on the front (south)- we never have any snow on the front. What I want to do is add insulation to the rafters (along with the styrofoam venting) thinking that this approach will keep the front roof from heating up too much. The roof already has ridge and soffit vents. Is this a valid idea? If so, how much more insulation should I add to the rafters? R19? R30? Thanks for the info.

[Joseph Meehan]

Is there any ventilation being provided to the attic? It sounds like it is too little. You should have vents low at the eves and high at the top of the roof. If you don't or you have blocked them, that is the reason for the problem. Don't try and heat this area until all the proper work is done, you may be creating damage from the ice dams.

[LADYHAWKE]

Joseph- Yes, the roof is ventilated to standard code. Soffits in the eaves and roof vents, even in the dormers. My convern is that I getuneven heating, even though I have the proper insulation.

-WSC

[Tom Baker]

The attic is gaining a lot of heat from the south roof surface and the dormers. Your attic has two dormered windows facing South. I'd suggest aluminum foil on the inside of the glass. Insulation can be added behind that.

Visit the Building Science Corporation web site for climate specific suggestions.

TB