Step 1 stretch a tape measure across the concrete slab and mark the position of the wall s ends.
How to add wall to existing room concrete slab.
Add all of the concrete right away so none of the mixture has a chance to dry out.
Make sure you have enough concrete to fill the entire area to the depth you desire.
The framing currently sits on an untreated 2x4 wooden sill plate.
Apply the new concrete over the primer.
Your local building code may call for the wall to be anchored to the slab with threaded rods.
Next check for joists running above the new wall.
Run a chalk snap line between the marks and snap the line against the slab to lay out the position of one of the wall s sides.
This prevents water from leaking under the bottom of the wall to the inside of the building.
I currently have a garage built upon an existing concrete slab i believe a plain 4 slab no foundation wall at the edges.
In order to add a bathroom to a house on a concrete slab you will need to locate the existing water supply and waste lines.
Remove the curb and clean the slab thoroughly with a wire brush.
Then fill the holes in the slab with hydraulic cement.
Sketch the new design in place if possible fine tune the design and then finalize the plan.
If this is the case drill through the curb and into the slab with a roto hammer every few feet.
Then design a bathroom layout that will function properly with the existing plumbing plan or with limited modification.
Pour concrete onto the existing slab until it is around where you want the final level to be.