Top coating a concrete patio

[xman23]

I have a 24' X 12' concrete patio that has a lot of open cracks. Other than the cracks the slabs are in good shape. Water has gotten in, freezes and pushes the slabs apart. They are all the same level. I would like to do is the following.

Drill holes thru the slabs and hammer in rebar into the ground, to stabilize the movement.

Pressure wash the cracks out and the top surface

Use a bonding agent fill the cracks.

Use a bonding agent and add a 2 inch top coat.

Question what material would you use to add a 1.5 - 2" top coat?

Thanks for any advice

Tom
.

 

[johneh]

concrete Fiber reinforced

 

[gzecc]

I am just learning about this now myself. My research has suggested to pour a minumum 4" on top and don't worry about it sticking to the existing. Might be better that it doesn't.

 

[Ashful]

I am just learning about this now myself. My research has suggested to pour a minumum 4" on top and don't worry about it sticking to the existing. Might be better that it doesn't.

I suspect that if you want to go this route, you're going to want some reinforcement in that 4" top slab, such that it doesn't develop cracks from independent movement of the lower slab. This might be as simple as wire mesh. There can be quite a temperature difference between the air on top of the upper slab and the earth supporting the lower slab, leading to some independent thermal expansion / contraction.

 

[Highbeam]

Drill holes thru the slabs and hammer in rebar into the ground, to stabilize the movement.

This won't do anything.

Cracks in the lower slab will make cracks in the upper slab so yes, reinforce to prevent the cracks from opening up too large.

Why not just fill the cracks in the current slab?

 

[xman23]

This won't do anything.

Cracks in the lower slab will make cracks in the upper slab so yes, reinforce to prevent the cracks from opening up too large.

Why not just fill the cracks in the current slab?

That's an Idea, just filling the cracks. I was trying to get a new surface look. I will give it a try and see what it looks like. It will be painted so maybe that will hide some of the patching

On the other hand I was hoping to add some stability to the base, and stop the water freeze from pushing the slabs. In the past the minimum slab was 4", but there is now polymers and other concrete mixes that allow thin coats. I don't know the structural strength.

I work in new construction. Today they make very little effort pouring level floors. Every room gets leveler poured in after the walls are up.

Due to the elevation, I can only add a max. of 2" to the top. The levelers is you mix it to a consistency of pancake batter, and apply multiple thin layers.

 

[seige101]

Quickcrete makes a concrete resurfacer.(http://www.quikrete.com/productlines/concreteresurfacer.asp) I recently used it in a local dog pound as years of urine and wash down had worn the surface. It's basically like a mortar mix with bonding agents and polymers and no aggregate. You mix it pretty watery and drag it across the surface with a squeegee or trowel. The end result looks like brand new concrete. It fills in minor imperfections, for larger cracks you pre-fill it and then top coat it.

It has a slight learning curve to it, you must keep it well mixed right until your pour it and you need to adequately dampen the surface you are going over. I pressure washed the surface with a heavy duty gas pressure washer and etched the surface and had great results.

 

[Highbeam]

I have removed several slabs now. My last one was a 12x20 under a shed. That one was 8-10 inches thick because the owner had family in the concrete business and mud was cheaper than gravel. It's really easy to break up a slab and if you can get a vehicle close to the slab it is no sweat to load the chunks. Kinda like working firewood but with smaller chunks.

That way you can build a proper new slab using modern materials and methods.

 

[mass_burner]

Quickcrete makes a concrete resurfacer.(http://www.quikrete.com/productlines/concreteresurfacer.asp) I recently used it in a local dog pound as years of urine and wash down had worn the surface. It's basically like a mortar mix with bonding agents and polymers and no aggregate. You mix it pretty watery and drag it across the surface with a squeegee or trowel. The end result looks like brand new concrete. It fills in minor imperfections, for larger cracks you pre-fill it and then top coat it.

It has a slight learning curve to it, you must keep it well mixed right until your pour it and you need to adequately dampen the surface you are going over. I pressure washed the surface with a heavy duty gas pressure washer and etched the surface and had great results.

Not to be a thread hog, but I am planning to do this with a 10' walkway that's seen better days. What did you use " for larger cracks you pre-fill it"? Also, can you paint this resurfacer?

 

[seige101]

I mixed up a small cup and poured it in the crack until it was fairly level with the existing surface, then 24 hours later covered the crack along with the rest with a top coat. I don't know about painting i did use a masonry sealer about 1 month after it cured. Don't see why you couldn't paint it or tint the concrete

 

[xman23]

I mixed up a small cup and poured it in the crack until it was fairly level with the existing surface, then 24 hours later covered the crack along with the rest with a top coat. I don't know about painting i did use a masonry sealer about 1 month after it cured. Don't see why you couldn't paint it or tint the concrete

How thick was the top coat? One layer or multiple?

 

[seige101]

I did 1 to 2 coats depending on how out of level the floor was. There is 8 runs for the dogs each with a concrete curb separating them. Each coat is about 1/16-1/8" thick