Stone & Mortar Foundation/ Basement Rehab

I just looked at an old stone and mortar foundation with crumbling mortar and concrete. An overlay of concrete was trowelled on decades ago was now coming off in chunks making the preparation a very labor intensive job. Here is what I recommended to do this job:

1. Go around the foundation and hammer off all the old concrete that is ready to come off. You can tell when you hit it and you get a hollow thud. The concrete overlay that is sound leave alone. Also work around the areas where some of the concrete has come off.

2. Wash all wall surfaces with TSP and then rinse with clean water. This will give you a surface to bond to with the Hydro-Seal 75. A pressure washer also works good on these types of surface provided to are vacuuming up the excess water as you power wash.

3. On very rough surfaces like this we like to use the very thick 1" or 1.25" roller covers and roll as much as we can and follow the guy rolling with a thick brush to cover all the areas missed with the roller. The 1st coat of Hydro-Seal 75 will act as a bonding agent for any mortar repair needed, giving it something to stick to.

4. Re-mortar all the areas where unsound concrete has been chipped out. My rule here is to use the Hydro-Seal 75 Mortar made by mixing 4 parts Concrete Sand mix to 1 Part mixed Hydro-Seal 75. Do all the thin patching first while to mortar is loose and the thick patch last as the mortar stiffens. This will keep it from slumping out of the holes and gaps. Use a straight edge trowel or wide putty knife to skim over your walls.
Packing the stiff mortar in with your hands also works very well.  Be sure to wear gloves to keep off your hands and wash hands and arms often with soapy water before Hydro-Seal 75 of Hydro-Seal Mortar dries on your skin or you will wear it for a couple of days.

5. A second coat of Hydro-Seal 75 will finish you job giving you a beautifully patched and finished Hydro-Seal 75 application.