Water pooling issue and drain advice.....

[GARover]

Hi gang,

I have a typical 2-car garage which the garage floor pad is on concrete slab. It appears that when the garage concrete was originally poured, something wasn't done right or it somehow bowed towards the middle. The garage floor is also slanted slightly towards the garage door and away from the house (which is correct), but most of the water never makes it there and instead just piles up in the center of the floor and has no where to go so I have a small pong in the center of my garage for a few months of the year.

This isn't usually much of an issue in the warmer months as the small amount of water that would collect there evaporates off quickly.

Where this becomes a major problem is in the winter months when melting snow from the cars just falls off and collects in the center of the floor.

So, I'm looking for a creative (i.e. low cost) solution to my problem and want to hear from others who may have had the same issue, or contractors with real world experience who can provide some options.

My thoughts:
I've sort thought about using the natural slope of the garage floor to my advantage and just removing a small amount around the center of the floor (where the water naturally collects), digging down to adding a gravel base for drainage, and then adding a drain and re-pouring the removed concrete.

Some have told me that a small amount of water like this from melting snow will just go down into the gravel layer (like a small drain field under the garage slab) and be fine. Others have told me I'll need to drain it out to somewhere else, which would be way more complicated, albeit not impossible.

It does get below freezing around here and the ground can freeze, so I don't want to create additional problems, but I will say I fully insulated my garage with R13 and 5/8" drywall this year and it stays much warmer in there now. FWIW, I'm also looking into a gas heater of some sort this winter, so hopefully the inside of the garage will stay above freezing even in the most extreme cold days.

Any advice or BTDT GREATLY appreciated!!

Any links to build threads where others added floor drains retroactively (and less evasively) greatly appreciated.

Thanks so much. Looking forward to hopefully getting some useful feedback or ideas.

 

[Kaizen]

try making a single straight saw cut as deep as the dip in the floor. so if its 1/4 inch deep set it at that and saw from edge of pond area to the garage door and out. if it is pitched correctly it should flow out. a larger cut could be used if its not enough. will have to hose it out a few times a year.

 

[rayra]

Seconding a light scoring to lead the puddle out. In an already existing expansion / crack-control groove.
I would not cut thru the slab or do anything to facilitate the water going thru or under the middle of your slab.

If the floor is really dipped or not sloped well, consider some 'self leveling' concrete mix to displace the puddle. In fact I'd even consider making a puddle and pouring the fill-in material right to the point that the puddle is displaced and runs out like it should. But that probably wont work in conjunction with the bonding adhesive you OUGHT to be putting down before the leveling mix.

 

[egdede]

If there is just a high spot between the 'pond' and the door, perhaps you could grind it down. I had a patio with a similar issue. Used a 4.5" grinder with concrete surface disc to grind off a little of the berm. Water flows nicely.

Wherever you would grind a groove: Look to see if the side of the puddle area is a grindable berm.

 

[GARover]

The garage floor is significantly bowed towards the center. It is not something where the "high spots" can be sanded down to fix. I'll take some pics tomorrow or the next day to help illustrate the issue more clearly.

I also do not like the idea of etching a channel into the garage floor for a number of reasons.

I have thought about using self-leveling concrete mix to fill in the void of the area where the water pools, but I had some concerns about how long it would realistically last. I guess i could apply an epoxy coating over it or cover with something like Trax tiles, but again, I was really thinking about using the natural bowing towards the center to my advantage by installing a drain.

I'd just be interested to hear some BTDT from people who have done it before, and how they went about doing it.

This is the type of drain I'd install, rather than a trench drain.

Hoping to get some feedback or some concrete information as to why this might not be a preferred solution to my problem. Thanks.

 

[matt_i]

My opinion is you don't actively want to wet the subgrade under the slab. Only bad things can happen, most notably the possibility is there that it will compact the subgrade "more" and then you have a void...which doesn't have to be a softball sized cavern to be an issue...if it were a 1/8" thick flat separation of enough size it can leave the slab cantilevered and unsupported then its very easy to crack,

What I would rather do is put in a drain which has a sump, either concrete or plastic, (could be cast iron or stainless steel if money is no object) that leads to nowhere. Essentially a catch basin with a grate. Let the natural air currents evaporate the water, it would probably concentrate in certain seasons. Allow removal of the grate so the sump can be bailed out if necessary.

 

[SGKent]

make sure it isn't a pre-tensioned garage floor before you grind or start cutting anything.

 

[GARover]

make sure it isn't a pre-tensioned garage floor before you grind or start cutting anything.

What does that mean exactly? I'm not sure how to tell this.

Its a typical 2-car garage bay slab. Not sure what I need to look for.

 

[SGKent]

tensioned concrete in garage slabs is common around here in housing the last 15 years or so. There are cables inside the concrete that hold it tensioned so it lessens the chance of cracking. I have seen some newer homes that have a warning label on the floor not to drill or cut into the concrete. Maybe someone here can explain it better who works with it. Cutting a cable releases the energy from that cable and that energy can cause bad things to happen.

Warning can be stamped somewhere on the slab or on a sticker in the garage or on the slab.

 

[Kaizen]

The garage floor is significantly bowed towards the center. It is not something where the "high spots" can be sanded down to fix. I'll take some pics tomorrow or the next day to help illustrate the issue more clearly.

I also do not like the idea of etching a channel into the garage floor for a number of reasons.

I have thought about using self-leveling concrete mix to fill in the void of the area where the water pools, but I had some concerns about how long it would realistically last. I guess i could apply an epoxy coating over it or cover with something like Trax tiles, but again, I was really thinking about using the natural bowing towards the center to my advantage by installing a drain.

I'd just be interested to hear some BTDT from people who have done it before, and how they went about doing it.

This is the type of drain I'd install, rather than a trench drain.

Hoping to get some feedback or some concrete information as to why this might not be a preferred solution to my problem. Thanks.

If that was a good solution we would have told you to do it. Besides the code issues you would create it would destabilize the soil, cause it to heave in winter, crack like san andreas, etc. You want to keep under that slab undisturbed and dry.
i've had good luck in my house with a self leveling floor mix. No idea how it will behave outdoors though.

 

[GARover]

It's not a tensioned garage floor. I could cut into it.

I read an older thread where someone had recommended exactly what I was thinking. A few others said code required a catch tray of sorts and then it can collect there and percolate down into the rock or whatever underneath without washing away.

I watched a few videos on the self-leveling concrete thing and I'm not sure it will work for a garage application with the weight of cars, large temperature fluctuations and occasional spills / chemicals. I'm interested to hear any BTDT though.

The other issue is I don't want the garage to actually be "level" as it slopes slightly away from the house wall and to the exterior garage door, which is correct.

I'd be interested to hear from others who may have used self-leveling in a typical garage where exposed to elements, salt, water and heavy cars, etc.

 

[johnnyradiant]

Don't get too hung up on the title 'self-leveling you could still get some slope out of it, or a bump. It needs a bit of help, otherwise it might even just run away when you placed it. There are products that are used in commercial parkades that stand up. It's part preparation and part right product for the application.

 

[Mick56]

One problem with have the floor slope towards the door, is in the winter, you have water drip off your car, and if it gets to the door, it can freeze there and stick the door down.

 

[rayra]

I'd just be interested to hear some BTDT from people who have done it before, and how they went about doing it.

You're already getting those answers, but I guess they aren't blunt enougH - DON'T PENETRATE OR SEVER YOUR SLAB TO LET WATER MOVE / DRAIN UNDER IT.

Your slab was fashioned improperly. The 'proper' way to fix it is to replace it, preferably by someone that knows what they are doing.
Short of that, you are being offered minimally invasive methods of draining it THAT DONT PUT WATER UNDER THE SLAB.

 

[In2toys]

What he said. no good will come out of draining water under a slab. I tear out concrete for a living. Either tear it out and re pour it, orrrr have a floor guy come out and grind down the area between the pond and door, then have them do a floor coating to make it aesthetically pleasing

 

[LS6 Tommy]

The garage floor is significantly bowed towards the center. It is not something where the "high spots" can be sanded down to fix. I'll take some pics tomorrow or the next day to help illustrate the issue more clearly.

I also do not like the idea of etching a channel into the garage floor for a number of reasons.

I have thought about using self-leveling concrete mix to fill in the void of the area where the water pools, but I had some concerns about how long it would realistically last. I guess i could apply an epoxy coating over it or cover with something like Trax tiles, but again, I was really thinking about using the natural bowing towards the center to my advantage by installing a drain.

I'd just be interested to hear some BTDT from people who have done it before, and how they went about doing it.

This is the type of drain I'd install, rather than a trench drain.

Hoping to get some feedback or some concrete information as to why this might not be a preferred solution to my problem. Thanks.

Check your local codes. Many areas do not allow garage floor drains.

Tommy

 

[zak77]

Here's my question about garages in areas that see snow and freezing conditions, typically i see slabs pitched towards the garage door but what happens is the snow melts off the car drains towards the door then freezes the garage door shut, not the best option. My garage is a little different where it has a crown in it so any water that comes off a vehicle will flow off to the sides. Not ideal since i have stuff up against the walls that i dont want getting wet. Center floor drains are now illegal to have. I usually dont park my truck in the garage in the winter but what is the best solution?? I really dont see a good solution to water drainage in garages that can experience freezing conditions.

 

[LS6 Tommy]

Here's my question about garages in areas that see snow and freezing conditions, typically i see slabs pitched towards the garage door but what happens is the snow melts off the car drains towards the door then freezes the garage door shut, not the best option.

I've never seen that in 54 years of living in NJ. Might happen in Minnesota.

Tommy

 

[ericlar80]

I could see you digging a relatively deep hole, putting a perforated pipe down there with that drain attached to it, and some filler gravel. Try to get the water a deep as possible (below frost depth) rather than dumping it right under the slab. This is probably works fine with snow from cars, but I'm not sure it would be great for wash-down in the garage.

 

[Three Widow's Garage]

I would think if you could round up a 5" or so core drill and put a hole down 5 or 6 feet place a perforated drain pipe, place a grate on it and be done. A round hole shouldn't weaken the concrete enough to be a problem. The overall amount of water that ends up in the garage is what a few gallons a day. 20 -30 days a year? don't think it will cause a sink hole. If it does, bust it out and re-pour it the right way. Any of the floor leveling products will never match the existing concrete nor will they last if used in large & thick areas.

 

[Kaizen]

Here's my question about garages in areas that see snow and freezing conditions, typically i see slabs pitched towards the garage door but what happens is the snow melts off the car drains towards the door then freezes the garage door shut, not the best option. My garage is a little different where it has a crown in it so any water that comes off a vehicle will flow off to the sides. Not ideal since i have stuff up against the walls that i dont want getting wet. Center floor drains are now illegal to have. I usually dont park my truck in the garage in the winter but what is the best solution?? I really dont see a good solution to water drainage in garages that can experience freezing conditions.

Spray silicone on the seal, place strip of wood under door, or my favorite is park outside.


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[GARover]

I would think if you could round up a 5" or so core drill and put a hole down 5 or 6 feet place a perforated drain pipe, place a grate on it and be done. A round hole shouldn't weaken the concrete enough to be a problem. The overall amount of water that ends up in the garage is what a few gallons a day. 20 -30 days a year? don't think it will cause a sink hole. If it does, bust it out and re-pour it the right way. Any of the floor leveling products will never match the existing concrete nor will they last if used in large & thick areas.

That's kinda what I'm thinking. I don't need to it to wash cars indoors or anything. It's just runoff from melting snow on the cars I put in the garage. If you see the amount on my garage floor that stays all winter, it's like maybe at most 3-4 gallons worth. I don't think any of this is enough to wash away my fill... And, I would add more rocks or something to ensure it has it's own little "drain field" of sorts. I just don't want a slushee puddle in my floor anymore and sans chiseling out the whole thing and repouring the slab, I'm not sure what my alternatives are.

Looking at self-leveling concrete, it looks best for indoors and on a totally flat surface. My garage is sloped towards the door, which creates inherant issues, I think.

I'm just trying to figure out the best method/solution specifics.

Thanks.

 

[Kaizen]

That's kinda what I'm thinking. I don't need to it to wash cars indoors or anything. It's just runoff from melting snow on the cars I put in the garage. If you see the amount on my garage floor that stays all winter, it's like maybe at most 3-4 gallons worth. I don't think any of this is enough to wash away my fill... And, I would add more rocks or something to ensure it has it's own little "drain field" of sorts. I just don't want a slushee puddle in my floor anymore and sans chiseling out the whole thing and repouring the slab, I'm not sure what my alternatives are.

Looking at self-leveling concrete, it looks best for indoors and on a totally flat surface. My garage is sloped towards the door, which creates inherant issues, I think.

I'm just trying to figure out the best method/solution specifics.

Thanks.

interested how you are going to drill down 6 feet. what if you core your slab and hit a large rock? bet it will freeze on the sides or rock or whatever you are going to fill this with and you'll be in the same place as you are now. why are you against running a groove out to the driveway? heck i would have been done with this 2 weeks ago

 

[Prospecter]

try making a single straight saw cut as deep as the dip in the floor. so if its 1/4 inch deep set it at that and saw from edge of pond area to the garage door and out. if it is pitched correctly it should flow out. a larger cut could be used if its not enough. will have to hose it out a few times a year.

Great solution that is elegant in its simplicity! Love this!

 

[GARover]

Great solution that is elegant in its simplicity! Love this!

How will this not just freeze and freeze the garage door shut in the winter? I'm very skeptical of this solution. Also once it hits outside, it will turn my driveway into a skating rink.

The inside of my garage is fully insulated and shouldn't freeze unless it is the few coldest days of the year.

 

[Kaizen]

How will this not just freeze and freeze the garage door shut in the winter? I'm very skeptical of this solution. Also once it hits outside, it will turn my driveway into a skating rink.



The inside of my garage is fully insulated and shouldn't freeze unless it is the few coldest days of the year.

If it’s melting inside it won’t refreeze inside. Yes it will ice outside but from what you say it’s not that much water. Well good luck


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