Anyone Get Ice Dam's?.

[Greg123]

Last winter was the first year I heated my home with wood, it was also the first year that I got ice dams built up over my gutters. I had my attic re-insulated 2 years ago and also had several new vents installed so I don’t think that is causing it . I think it has something to do with the wood stove since the stove chimney goes straight through the attic and then through the roof to the outside.

The Chimney must put off some heat into the attic causing the temp to rise slightly above freezing causing the melting and re-freezing over the gutters.

Any one else experience this?

 

[MountainStoveGuy]

Your theroy makes sense, my install is not like yours, but i get ice dams to the point that i have baseball bat size stalagmites down to the ground.

 

[Greg123]

Thanks for the replies,

I think my only solution to the ice dams is to install electric heating cables along the roof above the over hang and in the gutters. This should at least help with the ice build up.

The ice dams seem to be the thickest on the same side of the house where the chimney is. The farther away from the chimney the less build up.

 

[KP Matt]

The problem is that the roof is cooler just above the eaves/above the soffits, so there's differential melting/freezing. There are solutions short of installing the heating cables. Check out this link: http://www.cmhc.ca/en/co/maho/gemare/gemare_001.cfm

What sort of chimney ceiling support box do you have? Have an attic insulation shield?

A related question I've been meaning to ask is if there's any way to make sure those ceiling support boxes are sealed/insulated, besides the attic insulation shield?

 

[saichele]

It would seem like it would be cheaper to install and cheaper to operate (well, free) to just insulate the chimnet going through the attic. Probably wouldn't take too much - some of the foil bubble wrap stuff or some unfaced fiberglass. Just something to reduce the heat output of the chimney.

Steve

 

[elkimmeg]

Steve exactly the suggestion I was going to offer. Anyone who redoes your roof , use ICE and water barrier the first 3'

 

[Greg123]

The problem is that the roof is cooler just above the eaves/above the soffits, so there's differential melting/freezing. There are solutions short of installing the heating cables. Check out this link: http://www.cmhc.ca/en/co/maho/gemare/gemare_001.cfm

What sort of chimney ceiling support box do you have? Have an attic insulation shield?

A related question I've been meaning to ask is if there's any way to make sure those ceiling support boxes are sealed/insulated, besides the attic insulation shield?

KP -Thanks for the Link good advice.

What sort of Chimney Ceiling support Box - Not sure, it was installed by Fire place Dealer, I will have to look it up.

Have an attic insulation shield - Yes

 

[Greg123]

It would seem like it would be cheaper to install and cheaper to operate (well, free) to just insulate the chimnet going through the attic. Probably wouldn't take too much - some of the foil bubble wrap stuff or some unfaced fiberglass. Just something to reduce the heat output of the chimney.

Steve

Steve - Can you please explain, do you mean wrap the chimney (In the attic space) with Insulation?. Any chance of to much heat transferring into the insulation from chimney?.

 

[wtyamamoto]

I have also heard (anecdotal references) that those heating cables aren't much good also. What supposedly happens is it melts the snow at the edge of the roof where it runs. Since the radiant heat only extends beyond the cable a few inches, a new dam forms above the cable where the radiant heat off the cable doesn't reach and creates it's own problems. The new dam further up the roof keeps run-off pooled at the dam which can then infiltrate below the shingles.

Wayne

 

[elkimmeg]

Ice dam cables are sold by the thousands every year. They can be effective but once you turn them on you just can't just un plug them they have to run constant to be effective and they also burnout/ wear out.

Ice dams are a combination of micro climates possibly mini climate conditions lasting a certaint period of time. Snow fall amounts play a part cloudy and sunny days and temps all combine. That explains why some years they never occure while others they are a problem and also the roof orientation as to sun exposure. Gutters can act to promote buildup as they act as a resiviour to start them. Plugged gutters even more so. Some have found gutter removal eliminated the problem. Gutters do not retreave all rain either. Many times heavy rain wil flow past gutters. What they do best is control light and moderate fain falls. My house has no gutters. My house also has ice abd watter barrier installed on the first 3'. This ruberized product also seals around the penatrating nails.
There is a manual way to insure no ice dams. Snow removal off the roof. If you have had cronic ice dams then you know where it is criticle to remove the snow. Yes heat from the chimney could promote ice dams. but it also takes a snow cover. as far as wrapping a masonry chimney with insulation it could help. however do not wrap a metal pre fab it is designed to opperate around free flowing air.

What are the dangers of insulating pre fabs? Well I sloved the ice problem but the pipe could not breath and dissipate the required heat. I got it warm enough inside I touched off a chimny cresote fire. I got it too hot it warped. One would be better using solid packed insulated chimney pipe engineered to opperate that way or switch to tripple wall pipe I think that route is safer, then self imposed re engineering your existing setup with an insulation wrap

 

[MountainStoveGuy]

Not to mention, class A pipe has a 2" clearance to combustables, and fiberglass insulation is considered a combustable,

 

[MountainStoveGuy]

All chemistry aside, i know glass and sand doesnt burn, but, bat insulation is considered a combustable by code inforcers and the insulation manufactures, i think its because of the paper facing. I have not seen a firerated bat insulation before, doesnt mean that they dont exist. Ceramic wool is used to insulate pipe, and insulate stoves. Maybe Elk can shed some light here.

 

[MountainStoveGuy]

further research says that non faced fiberglass insulation is not considered a combustable. Thanks for pointing that out Gideon.

 

[velvetfoot]

Around here I see quite a few of the metal addons on the last few feet. They are usually shiny. I think the idea is that the ice slides off. The ones I see usually don't also have gutters.

 

[MountainStoveGuy]

gotta love the snow, i cant wait!

 

[wg_bent]

further research says that non faced fiberglass insulation is not considered a combustable. Thanks for pointing that out Gideon.

So If that's true, then why isn't it used for chimney pipe insulation? (Suspected answer: It won't handle 2100 degree chimney fire)

A trickey problem to solve, but How about this:

Build a box surrounding the chimney out of steel studs. Use fiberglass non-faced insulation or rockwool to insulate and cover with durock (check for fire rating of durock). Don't forget to insulate top of box somehow so the heat doesn't just go to top and create a small ice dam around the chimney.

Is the pipe double wall pipe in the attic? (seems like it should be) Seem's the best solution would be to wrap the pipe with rock wool though. Anyone know where you can get blanket rock wool to do that? How to attach?

 

[elkimmeg]

Warren Read my previous post. Class A pipe should not be wrapped with any insulation,
It needs that 2" air space to function properly. It is engineered as such. It has to dissipate some heat. However I do like the chase box idea providing 2" air space is preserved

 

[saichele]

Moving to a more 'active' approach, you could place a small, low wattage fan at the gable peak - presumably that's where the warm air starts to congregate. you could even switch it so it's only on when the stove is burning.

Steve

 

[KP Matt]

All this is forgetting that the reason ice dams develop is that there are differences in the temperatures of the roof - snow melts off the top and freezes before it reaches the edge.

But I am glad to hear that it is possible to build an interior enclosure for a Class A chimney, provided that 2" clearances are maintained; that's something I've been wondering about. One minor annoyance that I have is that I get a lot of condensation on the inside of the roof flashing.

 

[wg_bent]

Warren Read my previous post. Class A pipe should not be wrapped with any insulation,
It needs that 2" air space to function properly. It is engineered as such. It has to dissipate some heat. However I do like the chase box idea providing 2" air space is preserved

Ahh, makes sense.

Yes, my intention was to have some air space in an insulated chase, but the more I thought about it, that also seemed to me that one would just be concentrating the heat. Eventually it has to leave, so it would go up, creating a smaller place on the roof where the heat would melt the snow. Back to the ice dam problem. In rethinking, I'm not sure it's the right solution. I'm thinking better ventilation to remove the heat may be the ticket.

 

[Roospike]

I'll throw out some information . #1 I have a two story house. Going through the first floor i boxed the floor hole for the pipe with cement board the thickness of the floor. #2 I did the same thing for the ceiling of the second floor BUT i went all the way to the roof with my box of cement board. The second floor pipe was boxed in to the from floor to ceiling . So now the ceiling/floor of the first floor has the pipe boot , from the boot to the roof of the house is open but all boxed in . What heat that is made inside that box goes all the way to the roof and then the heat goes out the top per the pipe boot on the roof . No ice dams , the heat from the chimney inside the box in space goes out the roof boot and not into the atic . Pictured below shows the pipe in the second floor before it was boxed in . You can see the floor where the ceiling/floor is boxed in with cement board . Same as the second floor celing except it goes to all the way to the roof . The bottom box has 3" clearance to the pipe and the top box has 5" clearance.

 

[PAJerry]

We have had problems with ice dams here, especially since we average over 100 inches of snow. I always had a bigger problem when we used the open fireplace a lot since the brickwork of the chimney, which runs up through the center of the house, would get really warm and the snow around the chimney would melt. With the insert now installed, the brick does not get warm and I'm hoping not to have so much of a problem next winter. I've been meaning to get the roof rake. Oh yeah - I can't wait for the first snowfall and a nice fire in the stove!

 

[wg_bent]

Roo, is your box insulated? your solution is kind of what I was thinking originally, but I expected it to go through non-living space.


WOW is that room PINK Your S.O. wouldn't be a Mary Kay consultant would she?

 

[Roospike]

Roo, is your box insulated? your solution is kind of what I was thinking originally, but I expected it to go through non-living space.


WOW is that room PINK Your S.O. wouldn't be a Mary Kay consultant would she?

About the box being insulated , we have attic insulation up to it but nothing on the inside of the box . Normally tou would have to have an attic boot , we bought the boot but wanted the boxed in area to go higher so we ended up making the box with cement board and took back the attic boot . No Mary Kay here , the room is way more PINK that it looks in the picture .