Concrete pour/slab issue... help!

[rbkool]

So we have a recently completed single garage that we love (I have not yet posted in the Gallery but hope to do so soon!). We subbed out all the work, including hiring a GC. All work was done well (best I can tell), but an issue has arisen that I would love some advice and input on...

When the slab was first poured, I noticed immediately (when the slab was still drying and I was watering it for the first couple days after being poured) that water was pooling in a corner opposite the garage door (i.e. toward the house, not the back lane). In fact, looking back at a picture from just a couple days after the pour, you can clearly see where the water is settling on the slab and not draining:

I pointed this out to my GC, who said it was not an issue, that all water would drain out correctly, and in fact "I would be able to wash a car in the garage and have it drain into the lane, no problem". I trusted his judgement and experience...

Fast forward to the garage being completed and the first large snowfall of the year (Toronto, Ontario). Sure enough, as the car melts off in the garage, water (and salt and road gunk) is pooling toward the front of the garage, and in fact reaching up to the drywall (where obviously damage can happen):

I have raised this issue with my GC, and he proposed to grind down the affected area which he claimed would solve it. He rented an industrial-sized (it seemed to me!) grinder and went at it for two full days. However, besides having a new "terrazzo" finish (with rock pits and scratches in the concrete), the water still pools in the same direction:

GC is now saying he thinks he can fix this issue by making a trench with a hand grinder , but I am starting to doubt his word (and work!).

We spoke to another concrete contractor, and he said the only option at this point is to rip out the concrete and re-pour . I would really prefer not to do that as it was a major chore getting the pour done in the first place as the cement truck could not fit in our back lane, so they had to hand-bomb it in with wheelbarrows. I am not overly concerned with the look or finish of the slab as I planned to finish the concrete with expoxy or some type of covering, but obviously that plan takes a back seat until we can get this issue resolved... help?

 

[acer66]

Not solving your issue but it might give you some leverage.
I am not sure what the laws are up north but in the US the floor has to slope towards the garage door
something like a 1/4" per foot in case of gasoline etc gets on the floor.

 

[CombatNinja]

Would it not be a thousand times easier and cheaper for all involved to just put in a floor drain in that area? Or was that what the GC was getting at with his "trench"? That looks like a pretty urbanized area so a floor drain in a garage may be a no-no. I am not talking hooking it up to sewer or anything, just a french drain more than capable of taking care of the volumes of water this situation causes.

I would be looking for someone else to do the work as you pointed the issue out to him when it was initially poured and he dismissed it and he thought he could fix a low spot by grinding it.

I would look at doing a self-leveling compound to get it filled in, install a french drain as an insurance policy, and then do the epoxy. On his dime. Oh, and I would'nt let him touch my floor again.

 

[lakeroadster]

Did your contract have anything in it about how to slope the floor? Sounds like your contractor is trying to help work through this, which is good, but if it ain't in the contract don't push him to hard. The devil is in the details.

If you don't do something the drywall won't last long if it is getting wet on a regular basis.

Other Options:

• Have a composite deck board placed around the perimeter and then seal it where the deck board meets the concrete. Buy a squeege and push the water out the door.

• Purchase a floor mat(s) with edging that will capture the snow / rain that drips off the car: http://www.autofloorguard.com/

 

[Falcon67]

Not solving your issue but it might give you some leverage.
I am not sure what the laws are up north but in the US the floor has to slope towards the garage door
something like a 1/4" per foot in case of gasoline etc gets on the floor.

I want all my shop floors flat as a coffee table, nobody ever quoted any such rule to me. I never get the truly flat floor LOL, but I work for it.

 

[acer66]

I want all my shop floors flat as a coffee table, nobody ever quoted any such rule to me. I never get the truly flat floor LOL, but I work for it.

Looks like I was quoting one of those urban myths or some nonsense out of my balding head.

 

[lakeroadster]

Looks like I was quoting one of those urban myths or some nonsense out of my balding head.

That is indeed a requirement if deemed a requirement by the applicable jurisdiction, for an attached garage.

IRC R309.4: "The area of floor used for parking of automobiles or other vehicles shall be sloped to facilitate the movement of liquids to a drain or toward the main vehicle entry doorway."

 

[penright]

The second picture with water on the floor coming from the wall are, is that the same slab that is in the first picture?
What is on the other side? Can you take a picture? I guessing the siding, then my next question is did it start lower then the slab?
If I am picturing right and that corner is an outside wall, then the issue is not the slope of the slab, even if you had inches of slope if water is getting inside then things are still going to get wet.
Needs to see pictures from the outside around that corner.

 

[acer66]

That is indeed a requirement if deemed a requirement by the applicable jurisdiction, for an attached garage.

IRC R309.4: "The area of floor used for parking of automobiles or other vehicles shall be sloped to facilitate the movement of liquids to a drain or toward the main vehicle entry doorway."

Thanks and so it looks like there is hope for me after all.

 

[rbkool]

Thanks for all the replies! Some good ideas in here (as I knew there would be!):

Would it not be a thousand times easier and cheaper for all involved to just put in a floor drain in that area? Or was that what the GC was getting at with his "trench"? That looks like a pretty urbanized area so a floor drain in a garage may be a no-no. I am not talking hooking it up to sewer or anything, just a french drain more than capable of taking care of the volumes of water this situation causes.

I would be looking for someone else to do the work as you pointed the issue out to him when it was initially poured and he dismissed it and he thought he could fix a low spot by grinding it.

I would look at doing a self-leveling compound to get it filled in, install a french drain as an insurance policy, and then do the epoxy. On his dime. Oh, and I would'nt let him touch my floor again.

You are correct about the floor drain not being allowed to hook up to the sewer in this area, and the issue is that even if a drain was possible, the concrete would still need to be re-sloped (is that a term?) so the water would actually run into it...a french drain to the back lane could work, but would be a ton of work!

Self-leveling compound was one option he offered, I am concerned about how a patch would look and how durable it would be, and if epoxy would cover it up?

Did your contract have anything in it about how to slope the floor? Sounds like your contractor is trying to help work through this, which is good, but if it ain't in the contract don't push him to hard. The devil is in the details.

If you don't do something the drywall won't last long if it is getting wet on a regular basis.

Other Options:

• Have a composite deck board placed around the perimeter and then seal it where the deck board meets the concrete. Buy a squeege and push the water out the door.

• Purchase a floor mat(s) with edging that will capture the snow / rain that drips off the car: http://www.autofloorguard.com/

Yah, our contract did not get to this level of detail, so I am working off his goodwill, which, to his credit, has been in good supply. This project was one of the first for this company, and they have gotten several referrals from me, so ensuring my happiness (and his quality of work) is in both of our best interest...

I like both of your ideas:

• I was planning on finishing the garage with some type of baseboard - the composite deck board would work well, and I believe is quite inexpensive...
• the floor mat with edging is likely the easiest and most practical solution to the most important issue - melt/runoff from the car ruining the floor/walls

The second picture with water on the floor coming from the wall are, is that the same slab that is in the first picture?
What is on the other side? Can you take a picture? I guessing the siding, then my next question is did it start lower then the slab?
If I am picturing right and that corner is an outside wall, then the issue is not the slope of the slab, even if you had inches of slope if water is getting inside then things are still going to get wet.
Needs to see pictures from the outside around that corner.

Thanks for the reply, but I think you have mis-read the problem - the water is coming from my car and running TOWARD the wall, not coming from the other side of the wall. That would be a whole other set of issues!

 

[topcok88]

I am by no means an experienced concrete worker but I did learn an old saying when I worked in the autobody industry. And it was, "you can't sand the low spots out". So with that frame of mine I would most likely attack your situation like this.
#1. Recognize that grinding the center of the slab and creating a sloping run to evacuate water may not be feasible.
#2. Because you know you want some type of floor coating I would look into seeing if tile is right for you.
#3. If tile is acceptable I would use self leveling compound, a grinder, and associated tooling to create a relatively flat/sloped/"whatever you want" garage profile and tile the entire garage.
#4. Because your sheet rock comes to the floor I would use a accent tile or possibly the same tile to tile up a course or so on the exposed walls. Ensure the bottom edge is sealed appropriately (I am going to guess some type of flexible sealant that will allow expansion and contraction).
#5. Enjoy your new beautiful space that will be more durable, with greater visual appeal, and easier to hide than I think using any type of roll on coating.

Just an opinion but with more and more tile garage threads coming around it really makes me wish I was ready to focus back on my garage and less on my basement woodshop! Hope you figure something out.

 

[cdestuck]

I had the same prob as you had. After years of doing the squeegee thing as I washed the car I fixed myself. I located a very nice 3" wide trench drain. I rented a wet cement saw and cut a 6" wide trench at the rear of garage and cemented this drain across the back and part way up the sides. My garage is pretty wide and deep sobin my case I put the trench 4' out from the wall rather than having the water run clear back to the walk. Works very well. Ps. I just drilled 1/2" holes in the bottom of the trench. This drains any water that enters the drain.

 

[lakeroadster]

I had the same prob as you had. After years of doing the squeegee thing as I washed the car I fixed myself. I located a very nice 3" wide trench drain. I rented a wet cement saw and cut a 6" wide trench at the rear of garage and cemented this drain across the back and part way up the sides. My garage is pretty wide and deep so in my case I put the trench 4' out from the wall rather than having the water run clear back to the walk. Works very well. Ps. I just drilled 1/2" holes in the bottom of the trench. This drains any water that enters the drain.

The water draining into the sub grade will eventually degrade it, resulting in the possibility of slab settling issues.

The better option would be to install the drain as cdestuck mentions and then put a sump pump at the end of the drain.

 

[SILVERPLATE]

I want all my shop floors flat as a coffee table, nobody ever quoted any such rule to me. I never get the truly flat floor LOL, but I work for it.

Built my new house two years. If it was in city limits it would have to slope, but I am in an unincorporated area where you do what you want. It's flat at my request.

 

[Falcon67]

The house has a slope, they do that standard on houses anyway. The shop not. Well, there is some slope toward the east side of the big door but only because somebody from the pour team stepped on the forms.

 

[lakeroadster]

The house has a slope, they do that standard on houses anyway. The shop not. Well, there is some slope toward the east side of the big door but only because somebody from the pour team stepped on the forms.

That *****...

 

[James-W]

Since I built my garage to be a workshop, the floor is flat except right by the overhead where there is a very small slope toward the door.

 

[steveo1o9]

I had the same prob as you had. After years of doing the squeegee thing as I washed the car I fixed myself. I located a very nice 3" wide trench drain. I rented a wet cement saw and cut a 6" wide trench at the rear of garage and cemented this drain across the back and part way up the sides. My garage is pretty wide and deep sobin my case I put the trench 4' out from the wall rather than having the water run clear back to the walk. Works very well. Ps. I just drilled 1/2" holes in the bottom of the trench. This drains any water that enters the drain.

That was not a wise idea. Overtime that water will erode the sub-base and you will develop cracking from creating a "sinkhole".

 

[Dirtydan69]

I had the same problem on a detached garage I had built in illinois except it was by the overhead door and water would infiltrate under the door for about 2 feet. I also had other issues like concrete splashed on my siding and attached garage door. They tried to clean it after it was dry but just did more damage. They decided to forgo their last contract payment of approx. $3700 and walked away. I replaced the bottom two panels of my garage door for 350 and resided my house and garage for 4500. Never did anything about the garage floor.