2 there is currently a few inches of gravel under the porch.
Fill void under concrete steps.
Once the holes have been set the geolift is injected in between the concrete and the dirt.
Connect a hose to a slabjacking pump then run the hose to the holes leading to the void.
Holes should be no less than six inches away from the edge of the concrete.
You might need two bags.
The foam will fill up the parts of the concrete that are uneven and will raise it to the proper height.
The first step is to drill holes in the problem concrete.
While this method of slab jacking is cost effective there are major drawbacks to opting for this type of repair.
Should it be removed or do i add the void filling material directly on top of the gravel.
It seems to me that i need to remove the gravel and fill the void with dirt and pack it in as tight as i can get it.
A sono tube is a cardboard tube available at home depot.
Once it hardens use some soil around the low spots and slope it away from the steps packing it down firmly.
I would use an 8 diameter sono tube cut to 30 which is your frost line fill it with quickcrete concrete mix.
Drill at least four holes through the slab at a point that s centered on the void beneath.
Use a hoe or fabricate a pushing stick and stuff the concrete into the crevice.
Geo polymer void filling is the best method we currently have for void filling but it cannot affect deeper layers of un compacted fill so you are left with supporting and densifying through polymer injection.
I would fill the area with concrete stone mix.
Mix the concrete to a thicker consistency.
Quickcrete concrete mix is also available at home depot.
This mix of sand cement and water is pumped through holes drilled to fill up the voids.
1 what material should i use to fill the void under the porch.
The grass will eventually fill in.
Immediate replacement of settled concrete or concrete with voids is not a good choice as settling is not yet complete.
A slabjacking pump is.
Smooth it out on the outside.
Use a drill equipped.