Concrete crack repair and bonding agents

[newbury]

I've got a fair amount of old concrete that needs "spot" patching in Virginia and Mississippi. I'm pretty sure we all know it's BEST to just tear it out and replace, then it will be good for 100 years.

I'm not really planning on being around that long, 40 years will probably do me fine. So I'm taking out the bad stuff, cleaning the cracks back to solid concrete.

I plan on using something like Henry 615 Patchpro but was wondering if I should also use some sort of "bonding agent".

Any recommendations?

 

[Tractor Seabee]

How about some pictures that show the extent and scope. There are different solutions for the various problems such as overlay, crack sealing, full depth area patch. How much is fair amount; I cannot find a definition for that term that is quantifiable. By the time you get all the patching done you may be just as well off functionally and probably economically replacing. The cracking is probably due to sub-grade problems; you will be putting a patch over what caused the initial problem, bound to repeat quicker than original. If the patch is bonded to the old a new failure will probably make the damaged area larger. It is real common, especially on DIY projects, to ignore providing a solid sub-grade under the concrete. The concrete does not bridge weak sub-grade well unless you do a structural slab. If it has wire mesh, it is probably in the wrong place to provide any value.

Ron

 

[Streetcar]

Many of the patching materials have bonding agent already added.
Sika is a good brand for various patching materials.
Check specifications as some material is good for thin patches but not thick ones. Some good for only thick patches.
Preparation is the key to long lasting patch

 

[newbury]

I've got a fair amount of old concrete that needs "spot" patching in Virginia and Mississippi. I'm pretty sure we all know it's BEST to just tear it out and replace, then it will be good for 100 years.

I'm not really planning on being around that long, 40 years will probably do me fine. So I'm taking out the bad stuff, cleaning the cracks back to solid concrete.

I plan on using something like Henry 615 Patchpro but was wondering if I should also use some sort of "bonding agent".

Any recommendations?

How about some pictures that show the extent and scope. There are different solutions for the various problems such as overlay, crack sealing, full depth area patch. How much is fair amount; I cannot find a definition for that term that is quantifiable. By the time you get all the patching done you may be just as well off functionally and probably economically replacing. The cracking is probably due to sub-grade problems; you will be putting a patch over what caused the initial problem, bound to repeat quicker than original. If the patch is bonded to the old a new failure will probably make the damaged area larger. It is real common, especially on DIY projects, to ignore providing a solid sub-grade under the concrete. The concrete does not bridge weak sub-grade well unless you do a structural slab. If it has wire mesh, it is probably in the wrong place to provide any value.

Ron

"fair amount" maybe 1,000 sq ft with cracks running 1/8" to 1/2" wide and 2' to 8' long. Usually 1 to 2 cracks per "slab". Slabs about 20x20. Most look like when they originally poured the concrete they didn't put in enough Contraction/Control Joints, long before I bought the place.

Many of the patching materials have bonding agent already added.
Sika is a good brand for various patching materials.
Check specifications as some material is good for thin patches but not thick ones. Some good for only thick patches.
Preparation is the key to long lasting patch

VERY HELPFUL, thanks!
I had only read the blurbs on the Home Depot Product Overview web page and they did not mention bonding included. Sort of like ads for 2 stroke oil may not include that they have fuel stabilizer included.

For prep I've a comfortable stool, a Bosch 1-9/16 In. SDS-maxｮ Combination Hammer drill (that thing is heavy, hence the stool) with a variety of bits to get the old stuff out, pressure air and water to clean the cracks.

I had been planning on using the Henry because I've used their products in the past.

 

[EddieWalker]

Most cracking is from too much water in the pour and when the concrete cures, the amount of area taken up by the water goes away and the cracks are formed. Cracks that happen from the soil will lift or lower the concrete where the cracks are happening and there is no repair for that until the soil is fixed first. In almost every house that I've worked on with cracks in the concrete, the soil is great. In the few that had legitimate soil issues, it was so obvious that there was nothing to do except remove the concrete and start over again. I've also learned that when people say that they have foundation problems, it's almost always framing issues up in their roof.

But to your question, Henry is a great product. So is Sika. For basic cracks, I would focus on cleaning out the crack as good as possible. Blowing air into the opening and running a shop vac over it to get everything loose out of there. Bonding agents are more for masonry type patches, which would be for bigger holes. For just cracks, use the caulking gun.

 

[Oldoak]

Many of the patching materials have bonding agent already added.
Sika is a good brand for various patching materials.
Check specifications as some material is good for thin patches but not thick ones. Some good for only thick patches.
Preparation is the key to long lasting patch

:thumbsup:

Along with what EddieWalker stated:

Bonding agents are more for masonry type patches, which would be for bigger holes. For just cracks, use the caulking gun.

 

[newbury]

<snip>
But to your question, Henry is a great product. So is Sika. For basic cracks, I would focus on cleaning out the crack as good as possible. Blowing air into the opening and running a shop vac over it to get everything loose out of there. Bonding agents are more for masonry type patches, which would be for bigger holes. For just cracks, use the caulking gun.

Thanks Eddie.
The area I'm working on first has 4 cracks about 1/2" wide on the top. My Grandfather had taught me (back in the '60's) to chisel out the old 'crete back to solid 'crete, then fill w/ mortar or mortar and sand (this may have been before bonding agents). So I started "chiseling" in between downpours (5" in one day:raindrop::raindrop::raindrop: ) and found it would usually widen about another inch till I got to good 'crete. I did that using the Bosch Hammer drill.

Other places I've got narrower cracks which look conducive to using a caulking gun.

But this thread was mainly about which bonding agents were best, because there are a lot of them. And I didn't realize the Henry product had bonding agents mixed in.

 

[EddieWalker]

Home Depoy sells Custom products in their tile department and its a very good masonary bonding agent. Henry has some stuff in the florring department that is good too, but for just a paint on type bonding agent, use Custom brand stuff in tile.