Then remove any existing paint or gunk using a power washer or scraper and wire brush.
How to prepare concrete wall before painting.
Scrub away any dirt grime or gunk that is stuck to the concrete.
Use sandpaper or a sanding block to dull any uneven surfaces wipe away dust with a damp cloth and let dry thoroughly.
Select paint appropriate for your outdoor project.
Any area large enough to let water in which is usually 1 16 inch or larger should be caulked.
Use a concrete primer which will help you get a smooth even surface that the paint can stick to.
Smoothing walls before painting is necessary for surfaces previously painted with a gloss or high gloss paint.
For exterior projects use a power washer to rid the wall of all dirt and dust.
Step 5 painting concrete block.
The best type of caulk to use in this case is elastomeric caulk.
For previously painted water based paint sand with a fine grit sandpaper.
The next step that you can do is to wring the rag and then try to wipe down your walls.
Repair any cracks or blemishes in your wall with concrete patch.
Before you paint and after you seal your concrete you need to prime your wall.
To make the best result in cleaning the concrete wall that is not already painted you also can add another bucket that you should fill with warm water.
Clean the concrete wall.
You will need a paint that is.
You ll probably need to wait about 48 hours after applying primer before you can paint but don t wait more than 30 days to paint.
Choose paint for your project.
Before painting make sure to seal all cracks and gaps.
Clean the concrete surface with soap and warm water removing any old paint.