Any concrete gurus here?

[Chunkee]

so poured this pad a couple of years ago. the day was too hot and the mix was too dry....

anyway, pour is ugly, but i really do not care about that, however, there is some uneven aspects in the slab. I put a new storm door in and when opened is scrapes the slab in areas.

i am looking at concrete surface grinders however, most of them say really no more than a 16th inch leveling difference.

perhaps this is not the right approach.

Goal is to get it a little more level and even.

any tipsters other than jackhammering the thing up and pouring it again?

jC

 

[Sluggo]

The ghetto fix would be to shim the bottom of the hinge side of the door away from the house forcing it to swing in an upward arc.

Beats the hell out of grinding concrete.

 

[JoLLyRoGer]

If it were me, (and I'm in no way a masonary expert, just an avid DIY'er). I'd take a 6" angle grinder to it and mill your concrete down until you have the desired clearance + about another 1/8-1/4". Then I'd get some self leveling concrete mix from the Depot and use a wide-blate trial to fill in the uneven areas and float it out until you no longer notice any surface imperfections.

My .02
JR..

Good luck with that BTW!

 

[Codewiz]

I have done concrete grinding. It will take some time but isn't hard work. I had to get my slab level before installing my bamboo floors. I grinded down about 1/4 inch

 

[BlueWeasel]

Originally posted by: JoLLyRoGer
If it were me, (and I'm in no way a masonary expert, just an avid DIY'er). I'd take a 6" angle grinder to it and mill your concrete down until you have the desired clearance + about another 1/8-1/4". Then I'd get some self leveling concrete mix from the Depot and use a wide trial to fill in the uneven areas and float it out until you no longer notice any surface imperfections.

My .02
JR..

Good luck with that BTW!

That sounds like a pretty good idea.

 

[MikeyIs4Dcats]

Originally posted by: BlueWeasel

Originally posted by: JoLLyRoGer
If it were me, (and I'm in no way a masonary expert, just an avid DIY'er). I'd take a 6" angle grinder to it and mill your concrete down until you have the desired clearance + about another 1/8-1/4". Then I'd get some self leveling concrete mix from the Depot and use a wide trial to fill in the uneven areas and float it out until you no longer notice any surface imperfections.

My .02
JR..

Good luck with that BTW!

That sounds like a pretty good idea.

it's a horrible idea. any exterior concrete where it will be exposed to freezing is not a place to use a topping. water will seep into the plane between the concrete and topping and when it freezes, it will spall off the topping. If you want it servicable, grind it down and leave it. If looks are important, replace the slab.

 

[rahvin]

Originally posted by: Chunkee
i am looking at concrete surface grinders however, most of them say really no more than a 16th inch leveling difference.

1/16" per pass? You can grind it pretty much with any diamond coated grinder. Thing is if you use a hand grinder you are going to get a surface that shows every pass and basically looks like ass.

After you get done you could do a surface coat of thinset or one of the comerical concrete resurfacing mix. The risk with them is if they don't get a good bond and you are in a freeze/thaw zone you will spall the surface eventually but if you do a good job you can end up with something that looks better than what you have now.

If you do a surface coat though you are going to need to take off a lot more than 1/16" (you will need at least an inch off). One thing you could do if appearance matters, after you get it diamond ground to where you want it you can rent a sandblaster and blast the surface smooth but it's gonna cost $$ to do that.

 

[BlueWeasel]

Originally posted by: MikeyIs4Dcats

Originally posted by: BlueWeasel

Originally posted by: JoLLyRoGer
If it were me, (and I'm in no way a masonary expert, just an avid DIY'er). I'd take a 6" angle grinder to it and mill your concrete down until you have the desired clearance + about another 1/8-1/4". Then I'd get some self leveling concrete mix from the Depot and use a wide trial to fill in the uneven areas and float it out until you no longer notice any surface imperfections.

My .02
JR..

Good luck with that BTW!

That sounds like a pretty good idea.

it's a horrible idea. any exterior concrete where it will be exposed to freezing is not a place to use a topping. water will seep into the plane between the concrete and topping and when it freezes, it will spall off the topping. If you want it servicable, grind it down and leave it. If looks are important, replace the slab.

It's a horrible idea if he doesn't seal it properly. Otherwise, I don't see any reason why that wouldn't work....I've used topping with exterior concrete with no problems.

Resurfacing

 

[Slickone]

Not to threadjack, but if there are concrete gurus here...salt (actually an ice melt mix I bought) ate chunks out of the surface of my concrete. Is it repairable? Then will it stay or easily come off again?

 

[JoLLyRoGer]

Originally posted by: MikeyIs4Dcats

Originally posted by: BlueWeasel

Originally posted by: JoLLyRoGer
If it were me, (and I'm in no way a masonary expert, just an avid DIY'er). I'd take a 6" angle grinder to it and mill your concrete down until you have the desired clearance + about another 1/8-1/4". Then I'd get some self leveling concrete mix from the Depot and use a wide trial to fill in the uneven areas and float it out until you no longer notice any surface imperfections.

My .02
JR..

Good luck with that BTW!

That sounds like a pretty good idea.

it's a horrible idea. any exterior concrete where it will be exposed to freezing is not a place to use a topping. water will seep into the plane between the concrete and topping and when it freezes, it will spall off the topping. If you want it servicable, grind it down and leave it. If looks are important, replace the slab.

I never claimed to be an expert, I just said that's how I'd approach it. I used this technique to level a slab floor in my garage between two expansion joints which were uneven (we converted the garage into additional living space) and it stayed that way for two years without any problems before the carpet was finally installed.

 

[rahvin]

Originally posted by: Slickone
Not to threadjack, but if there are concrete gurus here...salt (actually an ice melt mix I bought) ate chunks out of the surface of my concrete. Is it repairable? Then will it stay or easily come off again?

Don't establish a cause for the spalls. Properly cured concrete is generally immune to the effects of salt use in a typical residential situation.

You have two choices, a thin surface recoat of concrete or you can use a spall patch or epoxy depending on the size of the spalls. If it's just surface spalling where you have only lost the morter coat then you need to do a thin coat or slab replacement.

BTW, I'm not a fan of the thin coats, they aren't very good.

 

[huesmann]

How about you just adjust the hinges of the door and jack it up a 1/8"?

 

[MikeyIs4Dcats]

Originally posted by: JoLLyRoGer

Originally posted by: MikeyIs4Dcats

Originally posted by: BlueWeasel

Originally posted by: JoLLyRoGer
If it were me, (and I'm in no way a masonary expert, just an avid DIY'er). I'd take a 6" angle grinder to it and mill your concrete down until you have the desired clearance + about another 1/8-1/4". Then I'd get some self leveling concrete mix from the Depot and use a wide trial to fill in the uneven areas and float it out until you no longer notice any surface imperfections.

My .02
JR..

Good luck with that BTW!

That sounds like a pretty good idea.

it's a horrible idea. any exterior concrete where it will be exposed to freezing is not a place to use a topping. water will seep into the plane between the concrete and topping and when it freezes, it will spall off the topping. If you want it servicable, grind it down and leave it. If looks are important, replace the slab.

I never claimed to be an expert, I just said that's how I'd approach it. I used this technique to level a slab floor in my garage between two expansion joints which were uneven (we converted the garage into additional living space) and it stayed that way for two years without any problems before the carpet was finally installed.

it would be okay in an area not exposed to the elements, but a patio will spall pretty quickly.

 

[Squisher]

They have planers with serrated blades that'll do more than 1/16".

I had to level off a slab that heaved up in my garage before I sold my house because the city inspector said it was a trip and fall hazard. I took one side down a 1/2" easy.

 

[Ornery]

Originally posted by: huesmann
How about you just adjust the hinges of the door and jack it up a 1/8"?

Almost what I was going to suggest, which is cutting the door off at the bottom, and putting a wider door sweep on it.

Or, call my little brother to jackhammer the thing up and pour it again.