The reality is that you can use exactly the density foam that you need to lift the lid off the box and did not start out with too dense of a material for the job.
Using expanding foam to raise concrete.
Although fiberglass has been commonly used for insulation spray foam can actually outperform it plus with so many ways you can use spray foam this material certainly is handy now only if it could help us out with all of those concrete problems.
Specifically heavy concrete slabs that have settled over time and are in need of raising.
This process is much the same as mud jacking an older method that uses a concrete slurry mixture to obtain the same results.
Foam jacking is a concrete slab repair method that uses a high density polyurethane foam to raise the slab.
The average 4 inch thick concrete slab only weighs 1 3 of a pound per square inch.
Sand also has air in it but it may be a better option for the do it yourselfer trying to raise concrete.
Concrete lifters and levelers know that you raise a slab of concrete one side at a time.
Bags of post mix.
I m about to do a 60ft run of fencing and had thought about using the foam.
It seems though that the hole for a 10x10cm post should only be 15cm any bigger and you would need more than one bag.
Patch up the holes with concrete and your new driveway or sidewalk or walkway will look good as new.
After the geolift has done its magical work the last thing left to do is patching up the holes.
Smaller sections of sunken concrete can be cut out using a wet saw and then lifted out with a crowbar.
The stuff is designed to intentionally move whatever s adjacent to the gap it s being sprayed into.
Sika postfix is a two component pre proportioned polyurethane resin.
The foam will fill up the parts of the concrete that are uneven and will raise it to the proper height.
The following video shows how dramatically effective this is.
So how do you raise a concrete slab with foam.
Shore up concrete problems.
The foam will expand and harden filling the void in the ground and leveling the driveway.
Use 5 8 inch masonry bit to drill a hole through the concrete and spray the foam into it.
A good solution for diyers.
If it is done correctly.
Also if using concrete never put concrete on the bottom of the hole it will form a pocket round the post from which the water can t drain.
Locate the dips get the right equipment and foam.
It is mixed in the bag to produce expanding foam for supporting and backfilling fence mail box gate and signage posts.
They also know that when you raise one side you may lower another side.
Suitable for all types of posts including wood steel and pvc.