Sand any particularly bad areas of concrete with rough grit sandpaper.
Sanding concrete close to a wall.
How to sand concrete walls step 1.
Attach a diamond sanding pad to a hand held grinder.
4 thoroughly sand the concrete.
A diamond pad is the only type strong enough to cut through.
Once your mortar is made begin spreading it over a small area.
Wash the walls with dishwashing soap and water.
Sanding concrete using an orbital sander if you have concrete that is going to be exposed architecturally you can sand it by hand using wet and dry sandpaper or an orbital sander.
Trowel a 3 8 inch.
The process of mixing mortar is relatively easy and straightforward as long as you have the right recipe.
Once you have everything prepared you will need to mix the mortar.
Usually the patched areas are visibly noticeable even if the area gets painted.
Remove the soap residue by rinsing the walls with a sponge and.
Remove uneven patched areas of concrete by sanding it with an angle grinder.
The sandpaper you choose depends on the quality and intensity of sanding you want to do.
Patches of cement are often uneven and stand out from the rest of foundational walls especially if cracks in the original walls necessitated the repair.
After you have prepared the area it s time to choose your sandpaper.
Also like sanding a concrete floor it is best to start with an area in a corner or near a wall.
After sanding you should apply 2 3 coats of acid wash on the entire surface to hide sandpaper scratch marks from the concrete.
Normally you d start by using a coarse grit sandpaper that is in the range of 40 60 grit.
Do not try to make the wall level.