I just bought my first house and I want to prove to my wife that I'm a handy guy. The house was built in 1947. The foundation is made of cement blocks. The outside of the cement blocks have lots of moss growing on it. The basement has a sump pump system and stays reasonably dry, although it does get moisture.

Question #1: How do I prep my foundation to paint the exterior? What should I use to fill any cracks if I discover them? Any additional advice or tips?

I'll be digging down into the dirt a little bit to paint the foundation.

Question #2: While I have the perimeter dug up a little bit, is there any basement "sealing" or moisture prevention that I should do? If so, what do you recommend?

Thank you!

 

What type of construction is your foundation? rock, cement blocks, brick, poured concrete?

 

The construction of the foundation is cement blocks.

 

Pressure washing is probably the best and easiest way to prepare the wall for painting. There are paints specifically for foundations some are quite thick and have something like sand in them to give the wall some texture and would conceal the cement block a bit.

Basement sealing and water treatment is a whole other can of worms. How much effort do you want to put into waterproofing? A little bit around the perimeter at ground level is probably not worth the effort. To do anything effective you'll have to dig down to the footer and apply a coating to the entire foundation. And, as long as the trench is dug you should also install a perimeter drain.

 

Thank you. So I'll power wash, dry, seal any cracks, dry, then finally paint.

What should I use to repair any cracks that I see (if any)? A caulking material? Is there a specific brand of paint that you recommend?

Regarding basement sealing: That is consistent with what I thought. That is probably something that I would leave to experts because of the utility lines running into the basement.

 

Unpainted block needs to be primed with either drylok or blockfill - that will fill the pores so the finish paint doesn't suck deep into the block. It's usually best to use mortar or hydraulic cement on wide cracks but latex caulking is fine for minor cracks. Give the block time to dry out from the PWing process before caulking or painting.

btw - welcome to the forums!

 

If you have future plans to finish the basement, build an addition instead. There are few basements that can be finished for living space without issues. Doesn't mean it can't be done, but it can often have poor results.

While you are digging down a bit around the foundation, check the grade to be sure you have a good slope for rain to drain well away. Remember, in our climate the frost will lift the soil about six inches about 4' to 6' from the foundation. Less slope than that and all of the winter run off has to drain down along the foundation that remains unfrozen.

You may find a tar coating just below grade, but they are never 100% at keeping moisture out of the blocks. That moisture needs a place to go. It will either dry to the inside or wick up the blocks and dry to the outside. Once you paint the outside, all drying will need to be to the inside. Extensive reading on moisture issues in basements is available.

bud