Concrete patch, thin

[Paddy]

Hello all,

I have a concrete patio that unfortunately was poured such I have a big puddle at my slider after it rains.This is not a slab on grade that can be jacked up. It's on bar joists. I'd like to add a skim layer to bring it up the needed 1/4 inch to get the proper slope. The size of the area is 3ft by 7 ft from 1/4 in to feather edge. I plan to use a 1/4 inch stick to insure I have a clear line to screte to. Not worried what it looks like with regards to the color or texture as it will get covered in the near future

The material I have purchased is Akonakote Pourable concrete patch. I'd likely not mix it with as much water as it can take to make it truly pourable. I'd be concerned it migh "self level" and I want a tad of slope.

anyone have experience with filling a dip in a concrete exterior concrete slab this size? other material suggestions?

 

[Streetcar]

I have used the self leveling products from Sika.
If the area will be covered soon , why are you worried about a slope

 

[EddieWalker]

I've never used that product, so I can't comment on how well it works. What I will suggest is to be sure to use a bonding agent before doing this. It's hard for new concrete to stick to old concrete. The bonding agent is like primer, it soaks into the old concrete and provides a surface for the new concrete to stick to. I buy it from both Home Depot and Lowes in their tile section, and haven't noticed a difference from one another.

If I was doing what you are planning on doing, I would also look at the products in the tile section of the box stores. There are several designed for this that work well. I prefer Home Depot for this.

What are you planning on putting on top of it when done?

 

[Industrial Toys]

I have an area I would like to patch similarly. My worry is that at the perimeter the patch ultimately ends and would be paper then. Would this not just break and flake away with traffic?

 

[Paddy]

Eddie,

I plan to coat the deck with an elastomeric coating. I was going to post that as a different topic later. But since you asked; we built an all concrete home and it has concrete decks on bar joists. I figured with all that covered deck, I'd have an in door section for my tractor. So I have a garage under part of the concrete deck. The bar joists from Hambro have a "S" shapes spine to be embedded in the concrete deck. But this is also where hair line cracks form. So the garage for the tractor drips a bit in heavy rain. Ames Reasearch makes a concrete roofing system that claims to make it water tight. They also offer a speckle granite top coat for non skids, decent appearance. The cement patch was to address a low spot first so no more puddles outside the sliding doors.

 

[RDrancher]

I've applied quite a few of these products in the past. A squeegee trowel is the easiest way to lay it down. You'll find lots of other uses for them too. They were a specialty product when I purchased mine, but I'm pretty sure the big box stores carry them now.

 

[Paddy]

RDrancher,

The elasomeric or cement patch?

 

[RDrancher]

I've never used one for elastomeric, but I imagine you could. I purchased a couple different sizes for applying polymer/cement micro toppings after concrete epoxy injection for repairing cracks. It's amazing how fast one guy can cover a bunch of square footage. On a nice cool morning I mixed (with a drill motor) and applied over 1400 sq ft of micro topping by myself, including a broom finish. I had planned on doing that particular job in sections, but the 36" squeegee made it pretty easy...hustling of course. Since I've had the squeegees I've also used them for faux plaster, knockdown texture, and mudding and taping drywall.

 

[Egon]

Suggest the low spot be roughed up a bit with a needle scalar before application of the level coat.

Maybe an acid wash after the scaling??

 

[LD1]

I have NEVER seen a contrete patch job as you describe turn out with satisfactory results.

The 1/4" isnt the issue....thats doable. The issue is the the edges. Feathering to basically nothing. Whatever they use for the aggregate, there comes a point in the "feather" that the aggregate is thicker than what you need, and the edges end up like crap. Even as small as sand....there comes that point.

Aside from cutting out the section and re-pouring the bad area......the next best solution is:

1. Outline the perimeter. Everything outside is perfect.....everything inside needs patch, weather it be 1/4" or 0.010"\\
2. Rent a concrete grinder. Grind down around that line, and everything inside that line so that when you do patch.....its a nice 1/4" EVERYWHERE and no feathering out at the edges.
3. Use an epoxy based patch. Usually 3 part system. Resin, hardener, and sand. Epoxies have excellent adhesion to concrete.....and dont shrink when cured. My concern with anything that gets mixed with water.....is shrinking when cured. Which will cause it to not adhere well.