Filling hole under concrete stoop
#1
Member
Thread Starter
Join Date: Jul 2014
Posts: 22
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Filling hole under concrete stoop
Hi folks,
I saw a couple threads on this, but I'm still unclear on the details. I'm very new to any kind of DIY stuff.
We have a concrete front stoop. Three steps, small porch, all one piece. the porch is not tied into the foundation of the house. see picture below.... The house was built in 1997, we bought it last summer. The home inspector pointed out that there are visible gaps under the concrete.
I'm pretty sure we need to fill those gaps, but I'm unclear on how. I read about "slab jacking" but that sounds like overkill for this. I also read about filling the holes with gravel or cement, but to do that right you need something to hold the gravel or cement in place, right? Do you dig down and build a form or something?


Thanks for the help!
I saw a couple threads on this, but I'm still unclear on the details. I'm very new to any kind of DIY stuff.
We have a concrete front stoop. Three steps, small porch, all one piece. the porch is not tied into the foundation of the house. see picture below.... The house was built in 1997, we bought it last summer. The home inspector pointed out that there are visible gaps under the concrete.
I'm pretty sure we need to fill those gaps, but I'm unclear on how. I read about "slab jacking" but that sounds like overkill for this. I also read about filling the holes with gravel or cement, but to do that right you need something to hold the gravel or cement in place, right? Do you dig down and build a form or something?


Thanks for the help!
Last edited by Angela Knobel; 04-24-15 at 12:32 PM.
#4
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Has the stoop sunk or shifted at all? Put a level on it, if you can't tell by eye. The stoop should have footings 30" deep there although that wouldn't explain why the land would wash away.
#6
Member
Thread Starter
Join Date: Jul 2014
Posts: 22
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Thanks!
It is *pretty* level... according to the level on my iPhone it is 1 degree lower on the side that has the hole.
And, stupid question, but what do you mean by "dig down to solid ground"? What's the difference between solid and unsolid?
It is *pretty* level... according to the level on my iPhone it is 1 degree lower on the side that has the hole.
And, stupid question, but what do you mean by "dig down to solid ground"? What's the difference between solid and unsolid?
#8
Member
according to your pic, try a 2x4x18", compactible granular base, & a 3# hammer - you can probably figure out the rest
#9
Member
Thread Starter
Join Date: Jul 2014
Posts: 22
Upvotes: 0
Received 0 Upvotes
on
0 Posts
according to your pic, try a 2x4x18", compactible granular base, & a 3# hammer - you can probably figure out the rest
Sorry to sound stupid, but this is all greek to me.

#10
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes
on
0 Posts
That's how it translates from Greek. I would use an 8" diameter sono tube cut to 30" which is your frost line & fill it with Quickcrete concrete mix. A sono tube is a cardboard tube available at Home Depot. Quickcrete concrete mix is also available at Home Depot. You might need two bags. Just add water while mixing it until its the consistency of sherbert.
#11
Member
Thread Starter
Join Date: Jul 2014
Posts: 22
Upvotes: 0
Received 0 Upvotes
on
0 Posts
you guys are so helpful!
So, Pulpo..
...do you mean that vertically? dig an 8" by 30" vertical hole, put the tube in it and fill it with quickrete? Or horizontally? I figure you must mean vertically since you mention the frost line. So that would give me a footing of sorts, but not all the way up to where the stoop ends, right? I fill in the rest with gravel?
So, Pulpo..
an 8" diameter sono tube cut to 30" which is your frost line & fill it with Quickcrete concrete mix.
#12
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes
on
0 Posts
You were right the first time. The 30" is vertically. That's the frost line in your area. Cut a dip on one side of the tube so you have room to pour the mix but at the same time. When you get to the top, let the mix set a little. That way it will stay there as you bring the cement up to the bottom of the stoop. Gravel can go on the outside of the tube but it's not needed. Don't put it inside.
#13
How do we know what her frost line is? She hasn't told us where she lives or completed her profile. If she lives in a southern state, the 30" deep value is way overkill. If that's the case, I vote with stadry, and would just ram crushed gravel into the voids using a long 2 x 4, smacking the end being held with a 3-lb. maul. Easily accomplished in a few hours at most. And far less chance for complications from improperly installing concrete in sonotubes.
#14
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes
on
0 Posts
She didn't have to say where she lives. That's my expertise. The frost line is 30". If you think that the gravel is a better idea, give her step by step instructions.
#16
Forum Topic Moderator
If I remember correctly the frost line in central fla is 8" not that ever gets cold enough to freeze that deep but I've heard of northern climates being 4' .... maybe Pulpo has a crystal ball 
I still think digging down to solid ground and either using concrete or packed gravel [latter is probably better] is all that would be needed.

I still think digging down to solid ground and either using concrete or packed gravel [latter is probably better] is all that would be needed.
#17
Member
i'm not seeing any holes so perhaps this monitor's not worth a ****,,, looks to me like backing up shoulders or a sidewalk,,, are we making more of this than necessary ?
no, you do NOT dig out the hole - just put a shovel full of gravel next to the open space & start compacting w/2x4 & hammer,,, why dig out something you already have ? just be careful of that green snake,,, it looks like a 50 footer ! ! !
how could anyone even measure a frost line in fl ? even in atl, we don't get frost depth
missy, do us all a favor & tell where is your ' where ' - thanks !
no, you do NOT dig out the hole - just put a shovel full of gravel next to the open space & start compacting w/2x4 & hammer,,, why dig out something you already have ? just be careful of that green snake,,, it looks like a 50 footer ! ! !
how could anyone even measure a frost line in fl ? even in atl, we don't get frost depth
missy, do us all a favor & tell where is your ' where ' - thanks !
#19
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes
on
0 Posts
So it looks like Angela, the OP got spooked when she was asked to reveal her location & hasn't returned. For those who want to stay anonymous, using your maiden name & omitting your location isn't enough, especially when you post a pic of your stoop. She lives in MD, hence the 30" frost line.
#20
Once again, I'm simply amazed by your vast wisdom, Pulpo. Being able to determine a state of residence just by looking at a few close-up pix of a front stoop, is indeed a gift--something that us mere mortals can't begin to comprehend.
Any chance you'd be willing to share with us this week's winning Powerball numbers?
Any chance you'd be willing to share with us this week's winning Powerball numbers?
#21
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes
on
0 Posts
You just don't realize how important stoops are in tracking people. There used to be a guy in Cottage Grove who had powerball #s but he just can't do it anymore.