New Garage drain

[BoostN]

**NO CODES FOR FLOOR DRAINS HERE**

Hello all,

I broke ground on my new 32' x 50' garage this week.. I need to get my drains ordered so we can set them before we're ready for the concrete slab.

My thought process is to put a channel drain under each vehicle parking area. Thoughts?

I will be using the right side parking area for winter washes when it's cold. So a floor drain is a must have... I feel like I could get away with just that side, however, if I every park a car on the left consistently I would like to have one there as well for snow melt/water.

This is my planned layout:

 

[PopcornSutton]

Is your land such you can pipe it out and daylight it?

 

[BoostN]

Is your land such you can pipe it out and daylight it?

Yes. It will only be water from normal washing, rain run off.

 

[manwithtools]

Where in TN are you located?
If you chose to do under the vehicle, be sure the concrete crew understands the floor needs a slight slope in 4 directions toward the drain. another option is 2 or 3 feet from the overhead doors. The concrete could then have a gentle slope towards the door in only one plane, if that makes sense?

ETA: I meant so say a trench drain parallel to the garage doors.

 

[BoostN]

Where in TN are you located?
If you chose to do under the vehicle, be sure the concrete crew understands the floor needs a slight slope in 4 directions toward the drain. another option is 2 or 3 feet from the overhead doors. The concrete could then have a gentle slope towards the door in only one plane, if that makes sense?

Just south of Franklin.

I'm not a concrete guy but it scares me to depend on them to get it sloping in 4 directions under each vehicle. Seems difficult.

I thought about a linear drain in front of the two doors, but then water has to run all the way back and seems very inefficient.

 

[manwithtools]

Just south of Franklin.

I'm not a concrete guy but it scares me to depend on them to get it sloping in 4 directions under each vehicle. Seems difficult.

I thought about a linear drain in front of the two doors, but then water has to run all the way back and seems very inefficient.

Yep, getting the slopes right can be tricky. I'm building a similar size shop soon and I am facing the same dilemma about where to put the trench drains. Congrats on the garage BTW!

 

[ConCretin]

My preferred method is to set a drain in the center of each parking area 1 1/4" lower than floor elevation and pitch a 10x20 slab area to the drain. This provides 1/8" pitch the long way and 1/4" in the short direction. You could go with a touch less pitch and still be fine. All the water that runs off the vehicle disappears underneath leaving the surrounding area dry.

Any competent finisher shouldn't have any problem with this. They just have to screed from the drain to the main slab elevation in a circular path. You can set markers at the corners to assist in locating where the pitch starts and pull them as you go. Don't forget to profile your base the same way to avoid thinning out your slab.

 

[Jackfre]

I think I’d skip the interior drains in favor of a trench drain at the face of each door. In my last place with the painted floor I could simply use a 3’ squeegie to sweep out the water. Simple and kept the floor cleaner.

 

[manwithtools]

My preferred method is to set a drain in the center of each parking area 1 1/4" lower than floor elevation and pitch a 10x20 slab area to the drain. This provides 1/8" pitch the long way and 1/4" in the short direction. You could go with a touch less pitch and still be fine. All the water that runs off the vehicle disappears underneath leaving the surrounding area dry.

Any competent finisher shouldn't have any problem with this. They just have to screed from the drain to the main slab elevation in a circular path. You can set markers at the corners to assist in locating where the pitch starts and pull them as you go. Don't forget to profile your base the same way to avoid thinning out your slab.

Thanks so much for this post. It should really help give direction to the concrete crew if needed. I'm finding it challenging to put trust in most of the pole builders I've talked too. They have their "own" concrete subs in the local area, but now good way to know what crew you'll get. I'm starting to think I may hire the concrete separate from the rest of the building so I can see their work and know what I'm getting.

 

[manwithtools]

I think I’d skip the interior drains in favor of a trench drain at the face of each door. In my last place with the painted floor I could simply use a 3’ squeegie to sweep out the water. Simple and kept the floor cleaner.

Agreed, I meant to say trench drain near the doors in my earlier post. Regardless of where I end up putting the drain, it'll be trench drains.

 

[Fav Onefour]

My preferred method is to set a drain in the center of each parking area 1 1/4" lower than floor elevation and pitch a 10x20 slab area to the drain. This provides 1/8" pitch the long way and 1/4" in the short direction. You could go with a touch less pitch and still be fine. All the water that runs off the vehicle disappears underneath leaving the surrounding area dry.

Any competent finisher shouldn't have any problem with this. They just have to screed from the drain to the main slab elevation in a circular path. You can set markers at the corners to assist in locating where the pitch starts and pull them as you go. Don't forget to profile your base the same way to avoid thinning out your slab.

I am an absolute fan of that method.

I did my three stall with each having a center drain point. It's been a game changer. I'm in snow country and dealt with wet floors my whole life. Doing single point drains under each stall is a awesome. If I drive in with huge snow on vehicles, they will slop when big chunks drop. I usually just broom those under the vehicle. With floor heat the area between vehicles dries quickly. Takes a little longer if heat isn't running.

I've dealt with quite a few versions of trench/channel drains. I was good at removing covers and cleaning the drains. The bigger the drain, the bigger the shovel. They all needed cleaning.
Trench/channel drains already need slope for them to work properly. Go with a center point under each stall and use a smaller shovel. To go further on the subject of cleaning, I did the three stall without channels. Each stall has straight pipe coming up with a SS snap in grate. Another benefit of that method was my ability to fine tune the slope right at the drain. I did a finish grind right around the openings and ground the pipe at the same time.

I'm not kidding when I say the method has been a game changer. It's so easy to keep the floors dry and clean between vehicles. I ended up running all season water to the garage so I can wash the bays throughout winter. With the floor clean and dry, the garage gets used a lot. The winter project list isn't limited and it's a good entertaining space.

 

[BoostN]

All good info here... For drain selection.. anyone have favorites? I will admit, I looked at this brand:

Galvanized Steel Slot Drain Clean Out System

Maintain peak performance with our Galvanized Steel Slot Drain Clean-Out System. Durable and easy to clean, perfect for heavy-duty use. Shop now!

vodaland-usa.com

But it's a bit pricey since I would have to have two systems.

 

[Pennsylvania 39]

Yep, getting the slopes right can be tricky. I'm building a similar size shop soon and I am facing the same dilemma about where to put the trench drains. Congrats on the garage BTW!

I have a 30 by 50 I have a 2 by 3 drain in my wash bay and they are connected to 2 floor drains one in each bay and connected to my sink drain. My concrete guys slopped to each of the 3 drains I was really happy.. Good Luck on your floor. Slim

 

[TurnipTruck]

I have done concrete before, but not enough to be satisfied so I had a crowd of professionals do my latest 40x60.
I asked for a simple shallow shovel-wide trench but they gave me this foot-deep trench parallel to the doors and sloped the front 20’ to the trench and kept the back 40’ flat. Very happy with their work. I pump out the trench maybe once a winter.
,,

For my prior garage I sloped only her parking bay to a foot deep chunk of 6” pipe that drained into the gravel. Her bay was always dry while my bay (with a lift) was flat and always a mess.
We get several feet of snow each season.

 

[grzellmer]

Just finished my 32x80 with one floor drain. A slight slope around drain but rest is flat. I sealed the concrete with acrylic and squeegee whatever water is not close to the drain. (Prefer the floor to be mostly flat.) Squeegee takes a minute after a wash. Would not get too wrapped up around "slopes".