Fix for cracks in concrete?

[Tailgate]

Thought I'd ask a quick question since so many folks on the forum are handy and knowledgeable.

Patio porch is concrete/flagstone and in pretty good shape for this 10 year old house. I believe the patio was added on by the previous owner. There are several thin cracks that have developed.

Question: is there a simple way to seal these cracks to keep water from seeping into them. Last year, I sealed the entire patio The sealant I used was a waterproof sealant for natural stone. I believe the sealant did it's job on the surface of the patio but I don't know if the sealant penetrated the cracks or should I have used a different product on the cracks. I'm not looking so much to repair these thin cracks...more so to seal them up. I'm really hoping that someone knows of a DIY fix with another type of sealant.

Maybe some here could at least point me in the right direction.

Thanks in advance!

[calmloki]

I've used a concrete patch goop - you will see it used in big box stores to seal/fill cracks or holes in the concrete floors. Kind of a caulking compound. I think it looks like hell and it has pulled away from the concrete over several years - I'm using it in 1/4"+ cracks on an exposed aggregate driveway apron and didn't have a prayer of having a fresh clean bond.

Think with your pictures I'd go with "first, do no harm" and leave it alone.

[UnrealizedPotential]

I am not an expert by any means, but I had cracks in my driveway. So I went to home depot and bought some ready mix concrete patch and it seems to work pretty good so far. Some sealant was used previously and it did not work very well at all so I tried this.

[Aerides]

As a not particularly overly handy but creative type, I would probably look for some matching/gray tile grout, mix up enough to smush in the cracks, and then apply grout sealer.

[Car-Guy]

I've used the stuff shown in this video a few times. Both Home Depot and Lowes carry it. Works okay.

https://quikrete.com/athome/video-re...ing-cracks.asp

[COcheesehead]

Polymeric sand. Sweep it into the joints, hose it down, let it dry and you are good to go. It hardens like grout, but a thousand times easier to work with. They sell it at Lowe’s. https://www.lowes.com/pd/Sakrete-40-...c-Sand/3502168

[97guns]

I’ve used epoxy sealant on cement before and it doesn’t let any water through, i used gray on my garage floor but I believe they make it in clear as well so you can see your stone

[samclem]

You've got a tough situation there. Something is causing those cracks (settling of the base underneath? frost heave? expansion/contraction of the stones/mortar itself?) and nothing you put on top or squish into them is going to stop the cracks from progressing.

Unless you want to go through the trouble of widening the cracks, only something very "thin" (i.e watery) will even get into the tiny cracks, and I don't know of anything that is like that and which also has the stretch/resiliency to keep the gap sealed thrugh expansions/contractions.
If you are willing to chisel/saw the gaps wider (including the ones across the stones), then some good elastomeric sealants might work for awhile. The polymeric sand suggestion is a good one, but you'd need wider gaps (it won't go into hairline cracks) and it won't seal as watertight as an elastomeric caulk.

[splitwdw]

Quote:

Originally Posted by samclem You've got a tough situation there. Something is causing those cracks (settling of the base underneath? frost heave? expansion/contraction of the stones/mortar itself?) and nothing you put on top or squish into them is going to stop the cracks from progressing. Unless you want to go through the trouble of widening the cracks, only something very "thin" (i.e watery) will even get into the tiny cracks, and I don't know of anything that is like that and which also has the stretch/resiliency to keep the gap sealed thrugh expansions/contractions. If you are willing to chisel/saw the gaps wider (including the ones across the stones), then some good elastomeric sealants might work for awhile. The polymeric sand suggestion is a good one, but you'd need wider gaps (it won't go into hairline cracks) and it won't seal as watertight as an elastomeric caulk.

+1
There are so many variables when it comes to concrete and stone. How thick the slab is, if you are in a freeze/thaw zone, type of concrete. It makes a big difference too if the stones were set in the concrete base or were applied to the top of a concrete base. Have a friend that decided to put a slate stone top on his concrete patio. Didn't do proper prep and after the first winter, the pieces of slate started cracking and separating from the concrete base.

[calmloki]

Quote:

Originally Posted by Car-Guy I've used the stuff shown in this video a few times. Both Home Depot and Lowes carry it. Works okay. https://quikrete.com/athome/video-re...ing-cracks.asp

The concrete crack seal shown in the latter part of the video is what I used, thinking the apron cracks would allow gravity to help seal deeper into the cracks. Probably matches clean new plain concrete better than it did the exposed pea gravel aggregate of our apron.