[rshackleford]

i want to know your experience. do they work? how much frost and how fast? 20 amp circuit realistic?

any comments at all please.

 

[concretemasonry]

Where are you located and how big is the area?

Since this is early in the winter season, the use of insulated blankets could be preferable to take advantage of the heat within the soil below. It just takes some planning to make it simple and cheap.

If you are a real contractor you should have learned the local seasonal tricks and tips.

If it is very localized, some charcoal and a day or two does wonders. Placing heated concrete does also help because of the mass and thermal effects.

More information and information on the location is important since some people may think you are in FL or GA and not in Ontario or similar locations.

 

[rshackleford]

i am not a concrete contractor.

the temperature today was 10 below, we will have this cold snap for a few days and then we will be in the twenties. we have about a foot of frost.

we are trying to protect some scattered areas from frost so we can excavate for water line instalation. some areas are a trench width and 10 feet long others are 50 feet long.

we cannot use fire or anything like that. we are thinking about blankets so we could plug them into the invidual homes that water will serve.

we have about 50 homes to service.

 

[rino1494]

A GC that we do some work for has them. They claim that it will take 12" of frost out of the ground. I have no experience with them but I do have experience with ground heaters. We used one to take frost out of a commercial building so I could finish grade the floor for concrete. That will take 12" of frost out in 24hrs easily.

 

[rshackleford]

A GC that we do some work for has them. They claim that it will take 12" of frost out of the ground.

not to be a smart a** but that is the exact kind of answer i wasn't looking for!!!

when you explained the ground loop heaters and how long it takes, now that's the answer i was looking for. it involved a depth, a time, and a good or bad review.

thanks for giving me some info though.

 

[rshackleford]

i found that they make them in 3' x 25' and three can be hooked together.

powerblanket is the brand.

 

[Noodle]

The electrial company that I used to work for had a small enclosed trailer with a water heater filled with glycol and it used a 60 amp 2 pole breaker. We had about 200'-250' of hose and blankets and it would pull about 8"-12" of frost out in about 24 hours. I think it would heat up to 160 degrees. Our blankets were not electric but standard insulating blankets

 

[rshackleford]

we own a ground loop heater. i think we have 1000 or so feet of hose. this only works for one area, although it does work quite well and we have been able to thaw several feet of ground.

however, we have 50 scattered locations to thaw, so i am looking for something a bit more self contained.

it looks like the only manufacturer might be Powerblanket. has anyone used these?

 

[rshackleford]

we purchased 6 blankets 6' wide x 25' long.