crack sealer for concrete? hairline on exterior slab.

[SPIKER]

Hi all:

I had my pole barn slab done in 2011 and has been thru 3 harsh winters last year being REALLY bad one. Frost in my area was really deep over last winter and must have heaved enough to cause it to crack.

I have now 1 crack on the exterior slab that runs about 10 feet from the roll up door out to the edge. The mix was/is 6000PSI with fiber & mesh setting on stand offs in it. It has not "Moved" or "Separated" but I want to SEAL it up with something that is going to last just to keep freezing and thawing and damaging it more over the long term.

What I'm after is something commercially available that will prevent water penetration and freeze/thaw that pops it apart over time. Prefer something that can be sprayed on or poured on that wont discolor the concrete too bad & maybe only spot treat it. The crack is a hairline only at this point and I want to fill or fix it so it stays that way..

thanks

Mark

 

[EddieWalker]

Since the movement that caused the crack is under the slab, unless you can do something about the moisture under there, you will never stop the movement. The best bet is a silicone based concrete caulking that you force into the crack. Anything that covers the crack by spanning the crack will just crack again when the concrete moves again.

Eddie

 

[Gary Fowler]

I bought some crack sealer from Lowes that must be latex based because it smells like rubber burning when you grind it flat. It is a self leveling grout type that comes in a quart bottle. It does seal well but it may take multiple application because it creeps down in the crack over several minute time span so you have to keep putting more in the crack. This is a good thing though because you know it is going down to the bottom of the slab.
I used it on a crack in my shop where an offset 10x12 slab to the main 30x30 slab cracked. I had to make several passes with the sealant before it quit creeping and ended up with a ridge which I used a 4" grinder to smooth. It looks similar to concrete when dry, grey color.

 

[SPIKER]

Eddie true however the crack area is where a 4" pipe starts under the slab at. it is for future water/elec/propane lines to come into the barn (just in case.) but does not follow the pipe directly and nothing to do NOW regarding getting under the slab at this time. Just trying to find something that is thin enough to run into it and fill it to prevent water seeping in and cracking it worse over time.

the CRACK is very thin hair line now and mostly normal concrete crack type that is about .010 or less at it's widest spots.

mark

 

[jaotguy]

if it is a straight line , just run a diamond blade down it and make it a permanent stress relief line ... then caulk with flexible sealer as above ...

 

[Blade Breaker]

Used this once for the exact thing you describe. Works great.
DAP Products - Caulks and Sealants - DAP

 

[SPIKER]

if it is a straight line , just run a diamond blade down it and make it a permanent stress relief line ... then caulk with flexible sealer as above ...

it varies back and forth zig-zag about 6" so not the best solution but good thought! If only it was straight it would be perfect way to go..

Going to stop at Menards Wed to see what they have.

Mark

 

[SPIKER]

I bought some water sealer that seems to work well enough it is liquid runs down in pretty well. it does not have any "FILL" for voids etc but seems to waterproof pretty well to keep the moisture out of the crack.

some application pics and I took one today after the rain (including the spot where I spilled a pint.)

Pic of the crack close up from about 3" away for visual perspective a corner of a paper will NOT fit into 95% of the crack only a few spots is it wide enough for that so thick sealers was out.





pics of it going in and the video link above you have to click the pic of the sealer soaking into the crack.




Product I used was on sale at Menards for 17 bucks a gallon



And what it looks like after raining all day, yep it is WET but the surface does not appear to be letting any water get into it like the rest. guess it is a pressure wash and overall application time.



Mark

 

[jaotguy]

thats a "stone sealer" ... used to repel water and prevent spalling of porous stones and cement in colder temps too .... nothing you apply later will stick to the treated cement .... also helps prevent staining of stone / cement from acids ....

 

[SPIKER]

yep: seals concrete real well too. yes, it was cold temps this past year in the area, some real bad days near -20 and for nearly 3 weeks we didn't get much above freezing this past year. That is when I found the crack this year mostly do to depth of the freeze in area. that particular corner is the north east corner so worst conditions of the pad/barn area protected from sun by barn/trees most of the winter.


Was thinking of pressure washing pad area and coating entire pad but mud in/out of barn door on tractor wheels is a PAIN.

Anyone have a good way to deal with MUD on tires other than driving thru high weeds>?

mark