Cold weather raises driveway

[clare]

Depends what base you are on. Clay or sand. He said he is on heavy soil.. I',m on sand and about 2 feet of gravel under my driveway..

[Rebel1]

Actually, there is a 44" strip of concrete, the full width of the 2-car garage, right at the entrance, that had been replaced roughly 16 years ago. May that's the reason.

[Rebel1]

Thanks for the suggestion. I'm going on vacation in a few minutes. I'll followup when I return.

R1

[Rebel1]

to the street; the other discharges about where the blacktop meets the garage, but as I said 12 feet to one side. The driveway is 10 years old. The old one, which was completely ripped out down to bare soil, also showed the same cold-weather behavior. Even though it's only a cosmetic problem, and the blacktop will be level with the concrete once the weather warms, any ideas how to prevent this seasonal rise and fall? Thanks, R1

I distinctively remember telling the driveway company about the rise and fall problem, but I might have been talking to a wall. I'll know better next time.

Thanks,

R1

[Stormin Mormon]

Don't know. I have the same problem with my trailer and wooden deck. Winter, the deck comes up and then I can't close my storm door. Of course, winter is when I most need the storm door.

Did you have a clogged drain?

[trader4]

night, my driveway raises well above the level of the garage's concrete. h ttp://

The baking soda box i s 2" high. The edge of the blacktop closest to the box is raised about 1.5" ; about a foot further from the garage, the blacktop is maybe 2" high. The house is on a slab. Soil in central NJ is somewhat heavy, but not clay-like . The whole property slopes gently down toward the street, which is 100 fee t away. (According to Google Earth, the street end of the driveway is 3 fee t lower than the garage end.) Behind the garage is a utility room. A little far-fetched that the water under the blacktop gets there by seeping from t he back yard under the 28' slab to the start of the blacktop. I have two go od gutters taking roof water away from the blacktop. Each discharges its wa ter at least 12 feet from the sides of the blacktop. One discharges its wat er about 25 feet closer to the street; the other discharges about where the blacktop meets the garage, but as I said 12 feet to one side. The driveway is 10 years old. The old one, which was completely ripped out down to bare soil, also showed the same cold-weather behavior. Even though it's only a cosmetic problem, and the blacktop will be level with the concrete once the weather warms, any ideas how to prevent this seasonal rise and fall? Thank s, R1

ng happens until there is freezing weather.

eway, so moisture will get into the ground all along the area between the t wo sides of the driveway whenever it rains. Next year, after the driveway sinks back down, seal the seam so no water can get into the soil right alon g the edge of the driveay and the garage.

That's worth a try and certainly can't hurt. If it's not the major cause of the problem though, it will still lift anyway pulling the seal out with it, so it may not last. But even if it doesn't stay really sealed, even reducing the gap may help. They have a rope type product that you can put in the crack, if it's wide enough, then heat with a torch to melt.

Dig something so that any water along the edge of the driveway drains rapi dly away, to reduce the moisture in the ground along the side of the filled up seam. You will still have some heaving along the edge of the driveway, but nothing like what you have now. It is fairly obvious that the origina l installation was deficient in having good drainaige for rainwater under a nd along the edges of the driveway, so you will have to live with that unle ss you are willing to redo the entire apron area of the driveway with a pro per sand and gravel base.

Agree. The most likely root cause here is an improper base. The best he can do short of ripping it out is to get out there in a heavy rain and see how and where the water is flowing. Anything that can be done to get the water away from the sides where it can get under the asphalt should help. And you really need to look when it's raining. What you think might be happening based on grade, etc, and what actually happens may be different.

The idea of having a board to place on the concrete at the lifted edge that someone else suggested is a good idea too. That could help keep the asphalt from starting to crumble.

[Lab Lover]

So, you cannot point to any building codes or engineering guidelines? I understand.

[Lab Lover]

If you do not have a gravel bed of any kind under the asphalt, that is your problem. Building codes and engineering guidelines / practices call for 6 - 10" of well compacted gravel under the asphalt. In fact, the gravel is far more important, structurally, than the asphalt itself.

[Susan Bugher]

On 2/2/2014 11:32 AM, Rebel1 wrote:> After maybe a week of temperatures continuously below freezing, day and night, my driveway raises well above the level of the garage's concrete.

As others have noted, you have a frost heave problem. There's a pretty good overview of causes and cures here:

Any method that reduces moisture under the pavement should alleviate or cure the rise and fall problem.

Susan

[clare]

Put more air in the trailer tires.

[krw]

Don't even need to cut it diagonally. A 2x4 in front of it will do just fine. The car will "jump" that instead of putting pressure on the concrete edge.

[Stormin Mormon]

Tires not on the ground. Frame on blocks and shim.

[Rebel1]

r to the street; the other discharges about where the blacktop meets the garage, but as I said 12 feet to one side. The driveway is 10 years old. The old one, which was completely ripped out down to bare soil, also showed the same cold-weather behavior. Even though it's only a cosmetic problem, and the blacktop will be level with the concrete once the weather warms, any ideas how to prevent this seasonal rise and fall? Thanks, R1

Thanks for the excellent suggestion

[Rebel1]

Actually, it happens every year. I alerted the guy who did the new installation 10 years ago; the new blacktop was firmly against the concrete, but that wasn't good enough.

R1

[Rebel1]

Let's see if I understand the way gravel helps. If new water seeps below the blacktop faster than it can seep into the sand/soil layer below (and at the sides of) the gravel, the water will eventually fill the voids in the gravel layer. Then if a prolonged freeze comes along, the blacktop will still lift.

Thus a deeper layer will take a greater amount of water to saturate the voids. As long as at least some of the voids in the gravel remain filled with air, then the blacktop should not lift.

Is this the theory?

[clare]

Not quite. The gravel is to allow full drainage to below the frost line while providing a stable base to support the load of and on the driveway.

[hrhofmann]

That's the explanation that most folks don't understand, about the need for gravel and sand to go down to below the frost line,

[trader4]

If you had to use gravel down below the frost line, that would be 3 ft of gravel here. And a variety of materials are used, not just gravel. The main purpose is you want the asphalt on top of something stable, not soft soil, loam, mud, etc. The soft stuff is taken out until you get down to something harder and subtantial. So to do asphalt you take out the soil and replace it with stabilized base material, compact it, then proceed. If you want to see more, google "stabilized base".

[hrhofmann]

The frost line is proably not that deep right next to a building or large s lab of concrete. All I know for sure is that my driveway heaves no more th an 1/2 inch at most, and when it was put in I was a fanatic about having a proper base of sand and gravel, and it has apparently worked as the drivewa y has been in place for 20 years without any problems.

[trader4]

On Wednesday, February 5, 2014 11:03:34 AM UTC-5, [e-mail] wro te:

slab of concrete. All I know for sure is that my driveway heaves no more than 1/2 inch at most, and when it was put in I was a fanatic about having a proper base of sand and gravel, and it has apparently worked as the drive way has been in place for 20 years without any problems.

I agree that you need a proper stabilized base. But in northern climates it's not typical to excavate down to below the frost line and replace it with gravel or other material. The main thing is any soft soil has to go. Around here that's 6" to maybe 12". Below that if you have rock, clay, gravel, whatever, as long as it's firm and stable, you leave it alone. You put stabilized base material in to replace some of the soft material removed, bringing it back up to the right height.