I recently had my house re-sided from stucco to a much thinner Hardie Board. There is now a 3" gap between the foundation and patio. Both for considerations of water proofing and my spotty knowledge of concrete, filling this with simply concrete seems wrong.

enter image description here

Step 1 will of course be to clean out the gap. Beyond that, any suggestions on how or with what that gap should be filled properly would be appreciated.

  • Is that an electrical wire visible on the left side or is that steel wire used in concrete patio reinforcement. Where does it go? If that is electrical, thake care of that first. (Disconnect at both ends and run metal conduit where it lays beneath the surface of the patio.)
    – user113627
    Jun 14, 2021 at 2:59
  • @GWarner A good catch, but alas it is only a bit of phone wire that hasn't been hooked to anything for over 15 years. Were it live or needed, that would most definitely have been prudent! Yes, it is part of the clean out. Jun 14, 2021 at 5:16
  • Thanks. I was going to say concrete would be the simplest remedy. But I wonder is that bare earth at the bottom or does the foundation continue out towards the patio? And does the patio extend to the ends of this wall it sits up against? I'm formulating a possible fix but there are still questions.
    – user113627
    Jun 14, 2021 at 5:39
  • And what is the weather exposure? Rain? Water drainage? You don't want to do this wrong now, and make something worse later.
    – user113627
    Jun 14, 2021 at 5:50
  • @GWarner Thanks. It is bare earth. There is a fair amount of weather exposure but not as bad as it could be. It's partially shielded by decking and SLIGHTLY higher than nearby so as long as I don't fill it too low, the water shouldn't pool terribly. It's Denver so lower total rainfall but we still get some. The patio does surround the wall the whole way. Jun 15, 2021 at 0:47

2 Answers 2


If this gap has drainage at either end for water and/or ice melt filling it with coarse gravel (something water can seep through) should be enough. 3" from side of house, chances are the footer under the wall behind this gap extends outwards. To be safe it might be wise to check by taking a long screw driver or rod and pushing down to probe what is under the dirt.

But don't discount filling it with concrete in any case. It wont adhere to the patio or the foundation (you want this actually due to the weather and temperature changes, Just fold and press a 6 to 9 inch wide piece of concrete reinforcement mesh into the gap so none of it is above the patio deck (but also not completely flat at the bottom before tamping in Quikrete. Or hydraulic cement. A length of rebar tied to the inside of this 'tube' of mesh would even deter cracking along the width.


I would put ground fabric or plastic ground cloth down (to help prevent weeds). Then fill the gap with decorative landscape rocks.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.