Home & Garden

Gap underneath concrete slab (walkway)

  • Last Updated:
  • Jun 5th, 2018 3:39 pm
Tags:
[OP]
Jr. Member
Dec 27, 2011
125 posts
113 upvotes

Gap underneath concrete slab (walkway)

Hi there,

I've noticed that there was gap underneath concrete slab and am not too sure if I need to fill the gap with dirt or something? I assumed it was washed out when it rained hard last week. My concern is the walk way concrete slab will sink or be collapsed due to lack of proper support. Landscaping company is supposed to be out to start working this week and I am just wondering if I need to fix it before landscaping work gets started. Any advice will be much appreciated.

Thank you!
Images
  • IMG_9592.jpg
5 replies
Deal Addict
Aug 18, 2009
1870 posts
1311 upvotes
Toronto
I'm not an expert but i don't think concrete is supposed to be poured directly on dirt/soil. There should be 3/4" gravel underneath as that stuff doesn't wash out. I would re-fill the void with gravel. Definitely don't leave it as is.
Deal Expert
User avatar
Oct 23, 2008
17299 posts
15111 upvotes
GTA, ON
Question though, can that piece of cement even be lifted?
Tis banana is IRIE 😎

10% off is cold, 50% off is warm, 75% off is hot, but FREE IS RFD!
Deal Guru
May 29, 2006
10706 posts
3367 upvotes
chimaican wrote: Question though, can that piece of cement even be lifted?
its called mudjacking, they drill holes in the concrete and shoot some liquid concrete in to raise it, I don't know the limitations or the exact science behind it, but its pretty common to have mudjacking done.
Deal Addict
Nov 17, 2012
4726 posts
4225 upvotes
Toronto
chimaican wrote: Question though, can that piece of cement even be lifted?
Lifted for what? OP wasn't asking about lifting it, and certainly you aren't talking about lifting it to fill in underneath?

Is the landscaping company coming out to add top soil etc. to the yard along side the walkway? Pack some gravel in there etc. and then make sure it's backfilled with earth up against the walkway. It's clearly not poured to sit exposed like that.
Deal Addict
Aug 29, 2005
1507 posts
161 upvotes
Ontario
What about some spray foam big gap filler? Assuming you would get a nozzle in deep enough.

Top