PDA

View Full Version : frost heave



wareagle69
04-25-2009, 03:59 PM
any good ideas on preventing this?
i have clay as soiland have spent considerable time this week learning about soils and heaving but was just wondering if any of you have gone thru this.
my barn experienced allot of heave in the stalls this year

erunkiswldrnssurvival
04-25-2009, 04:14 PM
muddy soil heaves the most, in boston they use a lot of gravel and silt cloth in driveways and other places to control heaving well drained soil like sand heave much less than clay laden soils

wareagle69
04-25-2009, 04:21 PM
yes i read all that, but whats a good solution? other than thousands of dollars to dig up clay lay down drainage and gravel then course sand. gotta be a way some how

erunkiswldrnssurvival
04-25-2009, 04:35 PM
yes i read all that, but whats a good solution? other than thousands of dollars to dig up clay lay down drainage and gravel then course sand. gotta be a way some how
of course there is. mounding the existing soil so that it has a pitch inceasing run off and less soak in,is one method

erunkiswldrnssurvival
04-25-2009, 04:37 PM
aeration of the soil allowing evaporation is another method (just disc it up and let the sun work on it)also planting crab grass or other root mass forming plant will prevent heaves. we used to call that stuff angels hair and some call it hoar frost. the strings of ice that pop up out of the ground, when the sun hits it the mud gets slicker than a snail!

Rick
04-25-2009, 04:50 PM
There a not a lot of good options once it's built. Contour the ground around the barn, as Erun suggested, to prevent water build up. Look for low lying areas that may be natural catch basins for water. It doesn't have to be 100 feet across. Even a small area of 2, 3 or 4 feet can catch a lot of water. If you can channel your roof run off in some way. If you have gutters, great. If not, then you really need to contour to keep water away from the base of the barn.

RBB
04-26-2009, 06:29 AM
Frost heaves - you get far enough north - you are going to have some problems every time you build.

Friends called me once to fix a basement with frost problems. Supposedly they'd done everything right, back filled with gravel, etc. Frost had picked up the concrete block at the ground surface and moved the 12 inch block over six inches - leaving the upper part of the basement tottering. Reason, in the end, appeared to be four to six inches of garden soil the woman had placed against the foundation for her flower beds.

You ask about prevention. There are a number of ways to prevent this. Dealing with it after the building is up - is much harder. As mentioned above in preceding posts - most of the things you can do about frost heave are preparatory. Fixing a building after you've discovered there is a problem - is extremely complex.

I used to make some pretty elaborate preparations of outbuildings and decks. For outbuildings, best to dig down a ways, get rid of any vegetation or top soil, replace with gravel and float it all on a thick re-enforced concrete slab. It is also necessary, after laying down gravel, to tamp extremely well - or else you can let the gravel set for one or two years before building. I have a cracked garage slab which proves substantial tamping does not always do the trick.

Around basements, place four foot out with horizontal styrofoam sheets - that slant downward slightly to carry off rain and moisture. Buried about two inches at wall, they should be an inch or two off level (lower) at far edge. This keeps moisture away from wall and also keeps frost away from footing. Frost does not go straight down, it will go at somewhat of an angle, but not four feet worth.

For buildings set up off the ground (like a cabin with a wood floor) I used to use sonnatube and fill with concrete for posts, but I've had better luck just letting the post float on a small concrete slab and jacking when necessary. Some of the buildings of this type that I've built, a basement screw jack is part of the post system.

If possible, pick the soil where you are going to build. Bed rock is no guarantee you will not have frost heave. Sand is best for building. Clay is worst.

wareagle69
04-26-2009, 08:15 AM
good info rbb
last year barn was empty no heave, this year horses and lots of hay in the wind shelter on the east side which is where most of the heave occured, too much insulation on top of the groung which allowed to freeeze and heave i would suspect, so build new storage building and dig up wind shelter down 4 ft and repalce with gravel and sand for a start
the next barn will have an earth floor, tlaked to a freind it is working out well for him, no heave in the house but i do have 10ft basement so i am pretty deep although lots of heave on the driveway and walk to the house, once again no insualtion, also this year snow right off the bat ground had no time to freeze so that may have played a part in that too.

Rick
04-26-2009, 08:28 AM
Heave occurs because of cycles of freeze and thaw. When water freezes it expands about 9%, which is probably not enough to bust a concrete sidewalk for example. The strength and weight of the walk would force the water to freeze laterally and downward. BUT! during freeze thaw cycles in early winter/late spring then you will get ice formed, add water, more ice, add water, more ice until you have heave will beyond the 9% range because the original ice at that depth rarely melts. Then something as heavy as a building will move.

I didn't think about it earlier but adding a barrier to the perimeter of your barn might also prevent water from seeping into the soil. Although if you are on a hill or down drainage of any sort, hydrostatic pressure may move water into the area. At least black plastic or some other material would keep roof run off and rain from infiltrating around the barn. Just some thoughts.

wareagle69
04-26-2009, 08:35 AM
that is what i am contiplating rick, maybe dig 5ft all around the barn and replace the clay with gravel and course sand than also maybe sheets of styrofoam for added insulation the a foot of topsoil back to grow the grass for feeding my kids

crashdive123
04-26-2009, 09:13 AM
WE - here's a couple of links that might give you some ideas.

http://irc.nrc-cnrc.gc.ca/pubs/cbd/cbd182_e.html

http://www.doityourself.com/stry/frost-heave