Frost protection of fill
Frost protection of fill
(OP)
Does anyone have any experience in protecting fill during Canadian winter from freezing using straw or wood chips.
Would a foot or so on top of the fill help?
Thaks
Would a foot or so on top of the fill help?
Thaks





RE: Frost protection of fill
It is well documented that a surface layer of insulating material will reduce frost penetration. For example snow covered ground will have musch less frost penetration than an area kept clear of snow. The depth the frost will penetrate below the insulating layer depends on insulating value (thermal conductivity and thickness), initial ground temperature, and of course the air temperature over the freezing period.
RE: Frost protection of fill
I've never seen wood chips used, but can't see why they wouldn't work. We've used straw to protect continous continous and spot footing trenches and also floor slab areas. It works fine if it stays dry and the wind doesn't blow. Clean up is always a problem, especially if there is blowing wind. Either way, the material has to be removed before backfilling.
We also used insulated blankets. They work fine and are reusable, but if they get wet or frozen they must be dried out before storage. There are also available electric mats and heating pipe systems both of which can be expensive.
Basically, we ended up protecting only the footings, it is easy and cost effective. We let the floor areas freeze. Then, once the building is enclosed, we would rent some 1,000,000 btu LP heaters and thaw the floor subgrade out. It takes about 3-4 days per foot of frost thickness.
NEVER use water to thaw out a subgrade you plan to pour concrete on!
RE: Frost protection of fill
RE: Frost protection of fill
RE: Frost protection of fill
We have already applied 1 foot of woodchips over the fill, hoping that would limit frost penetration to 2-3 feet
One foot of woodchips should equal two feet of soil (as an insulator)
Anyway, I would be interested to hear from anybody with more experience with this.
Thank you all for responding.