Expert: Dan Griffin - 12/13/2010

Question
Hello, we just started building the addition to our house. Excavation is done now and covered with tarp, but i am not sure that our contractors are prepared to work in cold weather - it's snowing now ( Ontario, Canada) and there will be no plus temperature anymore. Everything is frozen now in the hole, the tarp doesn't help. what are the solutions for sealing the excavated area and heating it?
thank you in advance, Elena

Answer
Elena, winter adds many complications to building.  I don't know how deep they did dig, but usually an excavation is much warmer than the surface ground.  The air may be cold, but there is a lot of warmth in the ground.  Snow is an excellent insulator.

I'm fairly sure that a contractor in Canada is mentally and physically prepared to work in the winter season.  Concrete should never be poured on ice and needs to be kept above freezing for the first 3 days.  It generates its own heat and this can usually be accomplished by covering with insulating blankets. Lumber, drywall, roofing, and most materials are basically unaffected by freezing temperatures.  To make the men more comfortable, it is possible and usual to use "torpedo" type heaters when they can contain the heat.  A simple tarp with a heater can be quite comfortable.  There will be days where conditions do not warrant men working, so the process will probably go slower than normal.

With this small bit of information, have a conversation with your builder.  Ask him what he is planning to do to protect materials, workmen, and what his projected time frames are.  I would expect that he will tell you many of the same things I've mentioned and he will be able to give you specific remedies that he uses to keep his men working in the winter.