Ice Dams

[krux]

Good afternoon everyone!

I'll cut to the chase as I need your expertise and it's stressing me out.

I have a 24x24 garage that has R13 on the walls and an open hip roof ceiling (shallow ceiling, roof has two vents). I want to heat the garage this winter just enough to take the cold off (Minnesota) when working in it (5-10 times over the winter). I'm looking at 30,000 btu wall propane unit for the garage.

Ice dams, they are real and it can happen. Is there anything I can do with the current setup that won't cause damage to my roof? Do you shovel like 3' off around and then fire up the heater? Do you just hope for the best? Do you pray to the snow gods?

Lets hear from you.

 

[Copymutt]

Same design, same size, same BTU heater, no problems since 1996. No damn gutters either.

 

[theoldwizard1]

I have one area at the bottom of a valley that used to get very bad ice dams (not the best insulation at the top of the valley). I installed heated wiring. Not the best looking, but it works and in the past 4 or 5 years that I have had it installed, I'll bet I have not used it more than about 100 hours.

I looped it down into the gutters, so it melts anything there. I don't turn it on until I can see a dam rising out of the gutters.

 

[Showkey]

Insulate the ceiling .......if there is no ceiling build one. R 38 in the ceiling would be best. 5-10 times per season use ? Shovel the snow off if your on budget.8
R13 in the rafter space ? That’s not much.....

The attic and the roof deck need to as cold as possible.
If the roof deck is too warm from poor insulation or poor design ice dams are very likely.....ice dams form when snow/ice melts and refreezes blocking the water flow down.

Ice dams can be seasonal, vary due to conditions and random based on snow temperatures inside and outside, direct sun.

Heat cable can help......but........often just moves the ice dam further up the roof.

A lot of the time garages do not have ice and water shield ......depends on how the project was speced.

Getting the snow off the roof will work......but it’s a lot of work.

Similar recent thread:

https://www.garagejournal.com/forum/showthread.php?t=459758

 

[krux]

This is good advice. Keep it coming.

Sent from my LG-H872 using Tapatalk

 

[Kaizen]

Without a ceiling I doubt 30k will do much but raise the temp ten degrees. I run a 80k BTU trash can propane burner and I get ten degrees rise in 1000 sq ft.
Ice dams need constant heat for a day or so. You won’t have a problem


Sent from my iPhone using Tapatalk

 

[Ray916MN]

Insulate the ceiling/roof.

Exposure and pitch are also factors. Low pitch, north facing is more prone. If you get ice dams, they are easy to address. Ice melt in a stocking laid at regular intervals across the dams will melt channels which will prevent water from building up behind the dams and leaking throught the roof. Snow rake if you get deep build up.

 

[yeldogt]

It's always best to minimize heat loss to a roof .... the best defense against ice dams is proper design and construction .. and to limit the snow that gets trapped at a gutter.

An unheated building can get ice dams and leak ....

 

[Showkey]

It's always best to minimize heat loss to a roof .... the best defense against ice dams is proper design and construction .. and to limit the snow that gets trapped at a gutter.

An unheated building can get ice dams and leak ....

^^^^^^^^^^^^^^^^^