Best repair/improve of salt-damaged concrete?

Hi Fellas,

My garage floor has become BADLY PITTED/FLAKING due to the attack of melting road salt that is brought in by the wife's car every winter. My garage is not heated so it doesn't get hosed out until late Spring, which allows the salt to lay there for weeks/months to eat on the concrete surface.

What do you think of this idea:
I was thinking of renting a floor grinder and grinding the surface down ~1/2" (in May or June), then laying a cap of concrete 2" at the outer walls and sloping toward the center. I may install a simple crock drain grate (gravel dry well type) at the floor center. Then seal the entire floor with an epoxy, maybe like, U-Coat-It. I would hope then that the tracked in road salt next winter would melt/drain/run toward the center of the floor under the car (rather than toward the outside walls, corroding everything that's metal along the way!) and NOT destroy the floor's surface in the process.

Is that a feasible plan?
Do you think it would last for 5+yrs?
Does anyone have a better idea/suggestion?

Thanks in advance for any & all advice, opinions or suggestions!
Ryan W

There is a product that is painted on over cracked concrete, Lowes, Home Depot stocks it. It is an epoxy paint that allows concrete to adhere to it. You can put concrete over it and it will stick. Concrete will not stick to old concrete with out this epoxy. Use of this product will allow you to forgo all that grinding. You may want to seal the concrete to protect it, which should have been done in the 1st place.

UCoatIt and I'm sure others make a product that was designed to fill pitted cracked and broken concrete. I've never used it but I've seen the video that they send out with their product. It was a self leveling product and looked fairly easy to use. I'm sure this isn't than answer if you're correcting 1000 sq. ft. but it might be worth a look

Ryan Wilke said:

Hi Fellas,

My garage floor has become BADLY PITTED/FLAKING due to the attack of melting road salt that is brought in by the wife's car every winter. My garage is not heated so it doesn't get hosed out until late Spring, which allows the salt to lay there for weeks/months to eat on the concrete surface.

What do you think of this idea:
I was thinking of renting a floor grinder and grinding the surface down ~1/2" (in May or June), then laying a cap of concrete 2" at the outer walls and sloping toward the center. I may install a simple crock drain grate (gravel dry well type) at the floor center. Then seal the entire floor with an epoxy, maybe like, U-Coat-It. I would hope then that the tracked in road salt next winter would melt/drain/run toward the center of the floor under the car (rather than toward the outside walls, corroding everything that's metal along the way!) and NOT destroy the floor's surface in the process.

Is that a feasible plan?
Do you think it would last for 5+yrs?
Does anyone have a better idea/suggestion?

Thanks in advance for any & all advice, opinions or suggestions!
Ryan W

Click to expand...

Have you ever ground 1/2" off of an entire concrete slab? After watching the process and seeing how slow it goes, I'd avoid this route. My other question would how does grinding 1/2" of concrete accomodate 2" of new concrete at overhead and walk doors?

I'm thinking that a new 5" slab would be more effective long term if the answers to the following questions come out favorable:

How old is the existing slab?

Is there other damage like large cracks?

Does the floor pitch to the overhead doors without ponding water?

How long do you plan to live in the house?

Can the almighty budget handle replacement of the floor?


If the surface is already pitted and spalling, road salt off the cars is doing more damage below the surface as we speak. Eventually the old concrete degrades to a point where it starts to attack the new concrete from below. The other thing is that nothing guarantees that a new concrete topping will stick tot he existing slab.

On the plus side of your plan, if you have neighbors that you really want to irritate, grinding 1/2" of concrete off the garage floor will accomplish it quite easily. The amount of dust even when spraying water and vacuuming can be unreal. The project we had to do it on (between 1/8" and 1 1/8" for an entire high school gym) lead to more than one call to the fire department from concerned neighbors thinking the building was on fire from all of the dust pouring out of the open doors.

while anything is possible, I would be suprised if the salt were the root of your problems. it takes a LOT of salt to really deteriorate concrete. as a rule of thumb, about 7lbs of salt per cubic yard of concrete is considered the "Tipping Point" for concrete deterioration. more likely, your slab was made with bad aggregate and is deteriorating of it's own accord, using the water dripping off the car as the cataylst. the best thing to do in any event is to clean and coat the concrete to cut-off the infiltration of oxygen and water.

If his floor is wet and freezing/thawing. A little road salt is more than enough to get it going.

Fellas,

1st off, THANKS for everyone's replies!

Now some answers:

No, I've never ground down any concrete - I was just assuming I'd need to do it just to get the salt out/off of the rough surface in order to stop the concrete corrosion process ? by the salt. I was assuming that I couldn't just 'wash & sweep' it off then put an epoxy coating or sealer over on it.

The floor is approximately 20' x 18'. There is no man-door to the outside and a wooden step to the house door inside. So the only door "sill" to contend with would be the 16' wide overhead garage door.

I'm guessing the slab was laid back in '69 or '70.
No large cracks. Mostly large flakes (is that called spalling?) coming off.

The floor does NOT pitch to the overhead door. It does pond water and wander toward the side walls. That's why I thought I should resurface it & cause it to drain to an installed center drain. To drain the car runoff melt water toward the door would likely only freeze the door down, not run out since it isn't a heated garage.

I've been here 3 years, I hope to live here for at least 20+ years.

Well, "the almighty budget" may need to prioritize this project - only because: #1) I KNOW it isn't going to 'heal'
#2) I'm confident it'll only get worse with age
#3) I'm not going to get any younger.

I'd agree with your assumption that my, "...slab was made with bad aggregate and is deteriorating of it's own accord, using the water dripping off the car as the cataylst." I can see many areas where the builder cut corners, so I wouldn't be surprised if he didn't with the concrete garage floor as well.

Yes, the garage floor stays wet throughout most of the Winter due to a snowy and/or wet car getting parked on it every night. Yep, it goes through the freezing/thawing cycles as outside temps dictate.

So -- with all that being said, I'm not REAL worried about it's cosmetic appeal. What my main concern is with it becoming pitted worse to the point of where it could become a trip hazard and that it's simply a pain to sweep out with the surface being so rough.

So, what do ya all think now?
Can I stop the deterioration of the floor surface with a simple wash then apply a coat/sealer to it to, "...coat the concrete to cut-off the infiltration of oxygen and water."?

Thanks again!
RWilke

GearHead_1 said:

If his floor is wet and freezing/thawing. A little road salt is more than enough to get it going.

Click to expand...

If it has salt soaked into it it's not going to be doing much freezing, I wouldn't think. That's the whole idea of salt on the roads to start with.

A concrete grinding contractor can remove 1/2" of concrete without any dust if done with the correct equipment. (wet or dry) If anyone needs one, I can recommend guys in most parts of the country and abroad.

Good luck with the floor

There are products available for your problem that shouldn't require grinding. Ardex CD (Concrete Dressing) and Level Layer III by Dayton come to mind. Even if you decide to cover it with fresh concrete, something like Weldcrete from Larsen will bond new to old, if the old is solid. If the top is loose or flakey, you can rent a machine to get down to solid substrate. Depending on how deep you need to go, look for a grinder, a shot blaster, or my favorite, the scarifier. Be sure to hook a vacuum to these machines. A top coat will bond better to a textured surface, not a smooth surface.

Thanks again for the replies, Fellas!

rt66jt,
Can a novice operate a scarifier successfully?
I've heard of a scarifier, but never seen one run.

I will do some reading up on the products you mentioned: Ardex CD (Concrete Dressing), Level Layer III by Dayton and the Weldcrete from Larsen material.

Based on what I'm hearing, it's sounds like I could rent a scarifier, drill & pound a hole in the center of the floor to install a 10" - 16" diameter dry well crock, then sawcut a line from each tire area leading back toward the center crock for draining melt water and lastly, lay on one of the above mentioned coatings to seal and protect the entire floor.
Does that plan sound sensible and DIY doable?

Thanks!
RWilke

Ryan Wilke said:

Thanks again for the replies, Fellas!

rt66jt,
Can a novice operate a scarifier successfully?
I've heard of a scarifier, but never seen one run.

I will do some reading up on the products you mentioned: Ardex CD (Concrete Dressing), Level Layer III by Dayton and the Weldcrete from Larsen material.

Based on what I'm hearing, it's sounds like I could rent a scarifier, drill & pound a hole in the center of the floor to install a 10" - 16" diameter dry well crock, then sawcut a line from each tire area leading back toward the center crock for draining melt water and lastly, lay on one of the above mentioned coatings to seal and protect the entire floor.
Does that plan sound sensible and DIY doable?

Thanks!
RWilke

Click to expand...

You might do better laying a 1" sloped gradient on the new surface you put down, towards the door? A quick swill with a hose would see your floor cleared. A friend of mine in Norway just did this as he has the same problem, with snow and salt melting off his car.