I have a asphalt walk way that runs right next to my house and collects water. I have a outside sump pump near by, but there is a low spot on the asphalt next to the house that will always take water first.

I want to raise the gradient of the asphalt next to the house so the water flows down towards the sump pump away from the foundation. I was thinking about just adding a bunch of cold patch to adjust the gradient that I want. Its about a 7 ft area along the house that I would need to raise. Would that work? Would it look terrible?


You can certainly fill with cold patch, though for good adhesion you would need to start with getting the area really dry, which will be considerable work as it's a low spot that holds a puddle. What may happen, and is more likely if you don't get it well-dried out before applying the cold patch, would be water getting or staying between the patch and the old asphalt, causing the patch to pop loose when that water freezes.

Both the appearance and the odds of having it pop loose could be helped by sealing the whole area after patching to fix the grade, thus giving a more uniform color and also reducing water ingress.

There's no argument that ripping up and replacing with new hot asphalt or concrete would be less likely to fail long-term, and probably look better, but there's also no argument that it's going to cost a lot more and / or get out of your DIY comfort zone, depending where your comfort zone is.

A third alternative (since you are getting out the cold patch anyway) would be to cut a channel from the lowest part of the low spot to the sump, place a drain pipe in it, and then cold-patch the channel.

  • To cut a channel, I would need a circular saw with diamond tooth blade? Hose hookup to cool while cutting? Is there an easier way to cut a channel cleanly? I considered this, but thought cold patch might be easier for a DIY. I do own a circular saw already. – Johnny Z Oct 12 '18 at 13:48
  • I suppose you could, but I'd suggest a masonry chisel and a hand sledge (short handle, usually about a 4 lb head) - asphalt should not be all that difficult to cut, and it's considerably less noise and tool expense (diamond blades are not cheap) to get the job done. If using a diamond blade that requires water cooling, your existing saw is probably not a wise choice as it's probably not made to handle water - you can rent one, but you'd still have to buy the blade at most rental places, and the sledge/chisel is going to cost a lot less. Apply some heat to make it cut easier (soften the tar.) – Ecnerwal Oct 13 '18 at 0:44

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