Since it's so hot thought I'd ask about ice dams!

[sublauxation]

Since it's to hot to boat and I'm in the middle of summer projects, why not talk ice dams?

The south exposure of my 1 1/2 story house gets pounded by the sun. It's a steep roof and it's also a big surface that seems to match the suns angle perfectly. There's a 6 foot section of my gutter that is shadowed by the neighbors house at times and I get an ice dam there every year. The attic is well insulated and well vented. There are no plumbing or other through-roof vents nearby and the chimney is at almost the opposite corner. I'm pretty sure the problem is the sun.

Anybody have any experience with those electric cables. I've heard some say only put them in the gutter and downspout. The directions say it's okay to put them on asphalt shingles in a zigzag going up a foot or two. Any thoughts or other cures? Not a fan of my neighbor but moving his house isn't an option.

 

[jeeperman]

Re: Since it's so hot thought I'd ask about ice dams!

Make sure the attic insulation is not up against the roof deck ANYWHERE.

 

[Tim Frank]

Re: Since it's so hot thought I'd ask about ice dams!

Since it's to hot to boat and I'm in the middle of summer projects, why not talk ice dams?

The south exposure of my 1 1/2 story house gets pounded by the sun. It's a steep roof and it's also a big surface that seems to match the suns angle perfectly. There's a 6 foot section of my gutter that is shadowed by the neighbors house at times and I get an ice dam there every year. The attic is well insulated and well vented. There are no plumbing or other through-roof vents nearby and the chimney is at almost the opposite corner. I'm pretty sure the problem is the sun.

Anybody have any experience with those electric cables. I've heard some say only put them in the gutter and downspout. The directions say it's okay to put them on asphalt shingles in a zigzag going up a foot or two. Any thoughts or other cures? Not a fan of my neighbor but moving his house isn't an option.

If it is the 1-1/2 storey design that we have around here there are 3 distinct areas that require venting.
The Apex, and the 2 matching areas on each side of house behind the top floor knee-wall.
These not only need to be vented to the outside, soffit vents are good for the knee-wall cavities as well as gable vents, but also those lower spaces should be connected to the apex area by intra-rafter vents....sometimes called stryo-vents.
A ridge vent is also good for that peak space as well as gable vents.

The heating cables are usable both in gutters and on the roof shingles...but if you are getting consistent ice damming, ice and water shield for the first 36" covered with roll roofing or flashing is a good option.

 

[sublauxation]

Re: Since it's so hot thought I'd ask about ice dams!

A ridge vent is also good for that peak space as well as gable vents.

Have you used the cables?

I've got the styrofoam vents and ice/water barrier. I've actually not had damage yet but I don't want any either.

Being in Ontario I'm guessing you deal with this. I've read a couple places that say I shouldn't have gable and ridge vent but that didn't make a lot of sense to me. I installed ridge vent a couple years ago and am going to change some siding this weekend so I was debating about covering up two small gable vents for one of the side attics. I woulld think any breathing is better than none.

 

[Tim Frank]

Re: Since it's so hot thought I'd ask about ice dams!

Have you used the cables?

I've got the styrofoam vents and ice/water barrier. I've actually not had damage yet but I don't want any either.

Being in Ontario I'm guessing you deal with this. I've read a couple places that say I shouldn't have gable and ridge vent but that didn't make a lot of sense to me. I installed ridge vent a couple years ago and am going to change some siding this weekend so I was debating about covering up two small gable vents for one of the side attics. I woulld think any breathing is better than none.

In practice there is no such thing as too much ventilation, and I am not sure whether even in theory there is such a thing...

I haven't had to use cables...we did a major reno and added ridge vents, six gable vents...one in each of the three "compartments....at both ends.....styro vents and opened up the soffits and used vented aluminum soffit panels.

No problem since.
Many of my neighbours have cables on the roof and in the gutter, and seem happy with the results.

 

[sublauxation]

Re: Since it's so hot thought I'd ask about ice dams!

Do you have the typical 6 inch soffits, and if so did you use just the 2 or three inch wide strips or did you do fun the full vented panels purpendicular to the house? Hope that makes sense.

 

[Tim Frank]

Re: Since it's so hot thought I'd ask about ice dams!

Do you have the typical 6 inch soffits, and if so did you use just the 2 or three inch wide strips or did you do fun the full vented panels purpendicular to the house? Hope that makes sense.

The panels are ~ 15 3/4 " long, house face to fascia.

 

[rbh]

Re: Since it's so hot thought I'd ask about ice dams!

If you have a chimeny going through your attic /roof I bet thats half the problem.
In the winter time as snow builds up it acts as insulation, and if you burn lots of wood in your stove/fireplace the chimeny warms up considerably. melting the snow to the insulation level
I would suggest you place 2 wirlly gig style vents in the 1/4 way positions on each ends of the roof.

 

[BuzzStPoint]

Re: Since it's so hot thought I'd ask about ice dams!

My house has a small addition for the laundry, almost flat roof.
I replaced the sheathing and shingles , insulated well. Still Ice dammed up.

I bought a set of the ice cables for that area. Works perfectly. I plug then in when snow starts to stick to the roof then leave them on all season. In 2 years there haven't been any ice dams in my laundry.

 

[Tig]

Re: Since it's so hot thought I'd ask about ice dams!

Vented soffit as mentioned abouve and then check out Solar powered roof vents, they run when the sun shines and suck air out of the attic. That should help reduce the amount of melt.
I see those heat cables zig zaged on shingle roofs, but I've never used one myself.

 

[BuzzStPoint]

Re: Since it's so hot thought I'd ask about ice dams!

Vented soffit as mentioned abouve and then check out Solar powered roof vents, they run when the sun shines and suck air out of the attic. That should help reduce the amount of melt.
I see those heat cables zig zaged on shingle roofs, but I've never used one myself.

I did the zig/zag. Hanging the lower loops into the gutter, then the extra down and up the downspout.