Rising driveway

[Mat and Suzy]

I noticed that either my driveway is rising or the garage floor is sinking. At the join between them (they are separated by a 1/4" gap filled with a felt type material) the driveway sits about 1" proud of the driveway, whereas previously they were level (or close to level). There is no evidence of cracking on either surface. The house is around 20 years old, and concrete drive was resurfaced several years ago (nice job too from what I can make out).

I think the cold is responsible - it's -30F up here in Minnesota today, and has been in the 0 to -20 range for few days. Does this sound plausible?! Someone told me that the expansion of ice underground can cause roads and driveways to rise. I don't see any evidence of the garage floor having dropped. If I am lucky, the levels will revert to their original positions once it warms up a little....any views on that? If anyone can help me understand this any better, I would be very grateful!

TIA

Mat

[Jim & Lil]

Hi Mat and Suzy,

Yes you have a 'Frost heave" under your driveway. It is a collection of moisture that has formed underneath your driveway and heaves up during cold weather. I am writing from Canada and have driven in Canada's arctic highways. I have seen frost heaves on the highway (Especially around Muskeggy or swampy areas) where a vehicle would do damage if hit at highway speeds. A Good way to prevent this from happening is wait till the dead heat of summer and seal your driveway completely around the edges.

The heave will dissapear when the warmer temperature arrives, but beware as a sizable frost heave WILL crack up your driveway. Hope that was of some help...Jim

[Mat and Suzy]

Thanks Jim.

How do you seal the driveway? Do you mean some kind of waterproofing agent?

Thanks

Mat

[RB]

Sealing is a good idea, but I'd put more emphasis on improving drainage so that surface water runs away from your driveway rather than towards it (and under it.) Make sure the joint between the driveway and garage are sealed against water. Most hardware stores will have products that are used for this. What has happened is that water as gotten underneath the driveway and frozen. Some years when there is a lot of rain just prior to the first hard freeze these frost heaves will be worse. If the soil is relatively dry when the ground freezes the frost heaves will not be as severe. The driveway will go down when the soil thaws but may not totally return to its prior position. It would be a good idea to take care of this next spring and summer.

RD

Mat and Suzy wrote:

[Jim & Lil]

Hi Mat and Suzy,

I managed to seal my driveway with and ashpalt sealer...because my driveway is ashpalt. You mentioned in your 1st posting that your driveway is concrete. I don't know what product to use for the concrete, the only advice I have (the usual advice, unfortunately) is to go to the home Depot and ask if there is a product. Hope that was of some help (probably wasn't)...regards...Jim