Pour concrete onto the existing slab until it is around where you want the final level to be.
How to add wall to existing room concrete slab.
The framing currently sits on an untreated 2x4 wooden sill plate.
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.
Exterior wall on slab must be out on the edge an exterior wall must be placed on the outside edge of the slab so the exterior siding laps down and over the edge of the slab.
Then design a bathroom layout that will function properly with the existing plumbing plan or with limited modification.
Sketch the new design in place if possible fine tune the design and then finalize the plan.
Step 1 stretch a tape measure across the concrete slab and mark the position of the wall s ends.
First ensure the existing wall to which the new one will attach at a 90 degree angle has a stud immediately behind the new wall location.
I m considering either a replacing the 2x4 sill with a pressure treated 2x4 sill or.
Remove the curb and clean the slab thoroughly with a wire brush.
Add all of the concrete right away so none of the mixture has a chance to dry out.
Your local building code may call for the wall to be anchored to the slab with threaded rods.
I currently have a garage built upon an existing concrete slab i believe a plain 4 slab no foundation wall at the edges.
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.
Make sure you have enough concrete to fill the entire area to the depth you desire.
Apply the new concrete over the primer.