icicles on the house.....

[mga]

normally they form when warm air seeps into the attic space due to poor insulation or small openings. my attic is well insulated and i've never had a problem with them.

however, this year was different. they formed along the edges of the roof. my problem is that the heavy snows we had have covered my ridge vents, and, since i'm burning wood 24/7, my fireplace chimney blocks are radiating heat, which normally would have escaped out the ridge vents. i climbed the roof and shoveled them off so that the air can escape.

to resolve this in the future, i was thinking of wrapping the chimney blocks in the attic with insulation.

any adverse effects to doing this?

 

[bore_pig]

I don't know if I'd jump to anything based on this happening once. How long have you NOT had a problem with icicles?
To answer your ?, I don't see a problem with adding a little fiberglass. Might help keep your flue temp up for a cleaner chimney too.

 

[logbutcher]

Not to worry, icicles are like zits : we all get them at some time. We built to be super insulated, ridge vents, all seams and leaks caulked or foamed to hell....and still we get the icicles hanging off the edges. ALL the roof was covered in Grace Storm and Water Seal under the shingles to protect any seeping from under the roof ice.
No matter how cold or cloudy it is, there is always some warming of the roof snow, and some warming underneath, then re-freezing. I only clean off the roof snow when it gets over a foot or so. I'm lazy and hate the cleanup. Besides, it's fun to knock the big icicles down scaring the birds, kids, and deer.
We also heat 24/7, 100% with 2 wood stoves. This has been a cold year so far, and we like it comfortable inside , so some heat will get out no matter how well insulated.

 

[November Wolf]

It seems this year that the ice cycles are on everyones homes more than previous years. I know I have some recessed tin can lights that I wished I never did install. That is my greatest ice cycle forming machine.

 

[reaperman]

very common problem, Ice dams are their proper name around here. What happens is the sun and warm weather melt the snow from the top and the melted snow runs down deeper into the snow on the roof. Once it hits the roof it tends to follow the shingles down the slope of the roof. Normally the snow above the roof, insulates the roof, keeping it colder, which in turn re-freezes the melted water and a layer of ice is formed under the snow. When that ice slowly melts, icicles form, especially on the very edges of the roof.

 

[mtfallsmikey]

Got any power vents/turbine-type vents on the roof?..need to get that attic temp. down, can cause major damage...

Ask me how I know!.....:jawdrop:

 

[maplemeister]

Like everyone else here I had that problem for years in spite of the proper insulation and ventilated attic space. Most of my problem was occuring on a south facing roof where the ice would melt on a sunny day and then run to the outside edge of the roof and refreeze at night creating huge icicles. Finally had a roofer come in and install metal flashing along the edge of the roofline. I believe it runs about 30" up from the outside edge of the roof. I still get the melting and icicles but the metal flashing prevents the water from getting into the building and it is no longer a problem.

Maplemeister:

 

[mtfallsmikey]

Also...there is a special type of rubberized tar paper made to prevent ice dams, used on the lower edge of the roof...big in N. England.

 

[November Wolf]

Also...there is a special type of rubberized tar paper made to prevent ice dams, used on the lower edge of the roof...big in N. England.

I believe that stuff is called #####athane. It is used here alot also.

The cross out word is supposed to be a female dog.

 

[logbutcher]

Also...there is a special type of rubberized tar paper made to prevent ice dams, used on the lower edge of the roof...big in N. England.

Grace Ice and Water 'Paper' ---see above post. Nothing like the old "tar paper" used over sheathing. There are a few other manufacturers that make this VERY sticky water and ice -proof barrier commonly used in Canada and northern states on roof edges, shallow roofs, and surrounding windows and sky lights under flashing and siding. Great stuff but like Brer Rabbit will stick to anything on a hot day building.
Contractors have assorted names for the stuff:censored: .....they hate it.

 

[barkeatr]

i HAVE Had the same problem this year, my ridge vents are plugged.

I have never had ice dams before. Even though i have ice and water shield up the valleys and up three feet on the overhangs, the water still back up above the ice and water shield this year.

Luckily, i have a door in the gable end that i can open, and i cut a small gable vent in the other gable end.., so in the summer i have ridge vents and in snowy winter i have gable end vents. doing this stopped the ice build up.

I have R50 in my clgs...but inevitably there is heat loss..and you have to vent it to keep the roof cold.

tim

 

[A. Stanton]

Would it be possible to install a low-key vertical wall vent on each of the gable walls? My house has both, along with the ice dam membrane on the eave slopes of the roof and I never had any problems.

 

[mga]

i HAVE Had the same problem this year, my ridge vents are plugged.

I have never had ice dams before. Even though i have ice and water shield up the valleys and up three feet on the overhangs, the water still back up above the ice and water shield this year.

Luckily, i have a door in the gable end that i can open, and i cut a small gable vent in the other gable end.., so in the summer i have ridge vents and in snowy winter i have gable end vents. doing this stopped the ice build up.

I have R50 in my clgs...but inevitably there is heat loss..and you have to vent it to keep the roof cold.

tim

r50? looks like i'll have to catch up.

i went on the roof and cleared the ridge vents. i also left the access door open from the garage. the problem has been temporarily solved, but i'm still going to wrap the blocks with foil wrap insulation.

i never had icicles before either...just that we had alot of snow fall in a short time and the temps have been really low....no chance to melt anything.

 

[pickwood]

The icicles are not normal except during a melting cycle, And then should be small and disappear when snow or moisture has melted or evaporated. If you have icicles all year or the real large icicles, you have a insulation or vetilation problem. or both. The temp of the roof should be about the same from the ridge to the soffit and this should allow most of the melting to run off the roof.:greenchainsaw:

 

[logbutcher]

The icicles are not normal except during a melting cycle, And then should be small and disappear when snow or moisture has melted or evaporated. If you have icicles all year or the real large icicles, you have a insulation or vetilation problem. or both. The temp of the roof should be about the same from the ridge to the soffit and this should allow most of the melting to run off the roof.:greenchainsaw:

Mr Pickwood: the theory is fine, the practice in the real world of zero degree temps, sun, and heavy snow is otherwise. Most of us have R 30+ insulation, "cold" roof systems with plenty of ventilation, and air infiltration leaks well sealed with foam and caulking. The fact is ( and you're welcome to get out and see for yourself here ) that ice dams and icicles will build up with heat absorption on top of any roof. For example on a recent 6 F mid-day, the sun was melting top down on roofs. Even "super insulated" homes here are having ice problems; it is endemic to the cycles of long term cold and snowfall.
And yes, we do try to remove roof snow. Ain't as simple as it sounds in theory. This is not The Carolinas.

 

[pickwood]

Hey Mr Logbbutcher,

Your points are well taken- but I was speaking from experience of building homes in the 4000 ft plus elevation which is a different world to the rest of the Carolinas and has different building codes. Also, spent 10 yrs in northern IN and MI as a union carpenter and superintendent, working on residential, commercial and industrial projects. Thru my experience I have found that most building codes are not sufficient regarding the energy codes. I would suspect in Maine the your attic insulation should be at least R48 plus to combat the extreme cold in your area. I found working in the Midwest that many structures were not vented properly and almost all had some sort of heat loss that created ice dams. Not enough insulation and insulation gaps were the biggest culprits followed by improper ventilation. Many older homes that used gable vents were not enough- then many add ridge vent and that a mistake too. You cannot use gable vents and ridge vents at the same time- in many cases it will work against you and in extreme cases brings snow thru the ridge vents. Hope this helps and stay warm in Maine.

 

[mga]

Hey Mr Logbbutcher,

Your points are well taken- but I was speaking from experience of building homes in the 4000 ft plus elevation which is a different world to the rest of the Carolinas and has different building codes. Also, spent 10 yrs in northern IN and MI as a union carpenter and superintendent, working on residential, commercial and industrial projects. Thru my experience I have found that most building codes are not sufficient regarding the energy codes. I would suspect in Maine the your attic insulation should be at least R48 plus to combat the extreme cold in your area. I found working in the Midwest that many structures were not vented properly and almost all had some sort of heat loss that created ice dams. Not enough insulation and insulation gaps were the biggest culprits followed by improper ventilation. Many older homes that used gable vents were not enough- then many add ridge vent and that a mistake too. You cannot use gable vents and ridge vents at the same time- in many cases it will work against you and in extreme cases brings snow thru the ridge vents. Hope this helps and stay warm in Maine.

i agree with you 100%.

however, and i'm just thinking out loud here, would not the color of shingles make a difference? for example, black or dark roof shingles would absorb more heat from the sun versus white shingles. wouldn't that help melt roof snow and, in essence, cause some ice damn or icicles?

as i stated in my OP, i know what caused my problem, but, i do see some new homes with icicles, while others have none to little. i assumed this might be due to the shingle colors being used.

 

[pickwood]

MGA

The dark shingles will help with faster melting usually when the temps are above 0 degrees. The dark shingles could raise the temps in the attic area, but if the attic is insulated well with proper ventilation, the ice dams should be minimal. In the extreme cold, you have some icicles. My point is that you should'nt see large ice dams or icicles.

 

[mga]

MGA

The dark shingles will help with faster melting usually when the temps are above 0 degrees. The dark shingles could raise the temps in the attic area, but if the attic is insulated well with proper ventilation, the ice dams should be minimal. In the extreme cold, you have some icicles. My point is that you should'nt see large ice dams or icicles.

heh....you should see my neighbor's house....they are literally from the roof to the ground!!! he knows why, but i guess he's too lazy to correct it.

 

[johncinco]

I just throw a bunch of salt/chloride up there and they all melt off in a day. The ice damns can cause some bad water back up. They melt off with the salt.