How much slope to clear melting snow

[aventino68]

So assuming the building dept is happy with me putting a floor drain in, and I'm in the snow belt. How much slope do i need to get the water draining away off the floor? What's worked for others?

 

[Chris705]

I recommend 1/8” per foot as a minimum for a pitch inside your garage. Less than that seems hard for masons to maintain a constant pitch towards your drain and that may lead to puddles.

 

[ConCretin]

An 1/8” per foot is the minimum but you will still be left with bird baths due to the difficulty in getting a sloped surface perfectly flat. A 1/4” per foot would be better. You can get rid of most of the water but it’s pretty difficult to eliminate all of it. It’s still a lot better than the alternative of water running everywhere.

My preferred method of installing a floor drains is to place one in the center of each parking area. Set the drain an inch and a half low ( be sure to slope you sub grade accordingly to avoid thin spots in your slab). In a 10 x 20 area, this provides a little more than a 1/8” per foot the long way and 1/4” per foot across. The water drains back under the vehicle and the walking/working areas around it remain flat.

 

[Jim greengo]

Lots of places dont like floor drains in garages any more without some kind of grease intercepter.

 

[CJDave]

My floor slopes about 3-4 inches in 25 feet. No drains just a nice slope to the overhead door. All of the slop, slush, ice, snow, rain, salt, grit and whatever else she drags in on her DD just goes through the Free Flow tiles and drains to and under the overhead door. No problems in 5 years. Dave R.

 

[aventino68]

An 1/8” per foot is the minimum but you will still be left with bird baths due to the difficulty in getting a sloped surface perfectly flat. A 1/4” per foot would be better. You can get rid of most of the water but it’s pretty difficult to eliminate all of it. It’s still a lot better than the alternative of water running everywhere.

My preferred method of installing a floor drains is to place one in the center of each parking area. Set the drain an inch and a half low ( be sure to slope you sub grade accordingly to avoid thin spots in your slab). In a 10 x 20 area, this provides a little more than a 1/8” per foot the long way and 1/4” per foot across. The water drains back under the vehicle and the walking/working areas around it remain flat.

How does that compare with running full length drains along the front of the garage just inside the door and sloping it so the water runs out of the garage to the drain. I’ve seen a few with center drains and a few with drains along where the garage door is. Can’t see a downside to a center drain.

 

[aventino68]

I’ve found an oil/water separator that isn’t too expensive so I’m hoping to do it all in code

 

[Cougar]

My floor slopes about 3-4 inches in 25 feet. No drains just a nice slope to the overhead door. All of the slop, slush, ice, snow, rain, salt, grit and whatever else she drags in on her DD just goes through the Free Flow tiles and drains to and under the overhead door. No problems in 5 years. Dave R.

Was wondering how Race Deck works in snow country.
Was thinking you might have to take it out in the spring to clean the floor.

 

[burleyfarm]

If you plan to have tool cabinets and work benches make sure the floor is level around the perimeter 3 feet or so so that drawers stay shut and everything stays level. Generally your vehicles won’t be parked that close to walls anyway to be concerned with water or snowmelt.

My entire floor slopes from the back wall to the garage doors. Makes it a pita for my workbench leveling and I happen to have my tool chest against the same wall so I can’t open more than two drawers at once for fear of tipping. I need to figure out a new location for the tool chest once my insulation and drywall is done.


Sent from my iPhone using Tapatalk

 

[CJDave]

Are drains necessary? Let the liquid drain to the overhead door and out under the door. Unless a drain is mandatory it seems to me that a drain is just another maintenance issue. Dave R.

 

[Kevin54]

Get yourself a nice large squeegee. Only takes a couple minutes after the **** melts off. I'm lucky as I only live 2 miles from a car wash, so if I have **** built up under the fenders from the snow, I'll hand powerwash it at the carwash, then drive slow back home. Let the water and what little snow came back on there on the drive, then squeegee it out.

 

[48windsor]

Thank you all for input . I want a slope to drain water or if I want to hose floor .
Some real good points were brought up that I didnt think about .

 

[aventino68]

Are drains necessary? Let the liquid drain to the overhead door and out under the door. Unless a drain is mandatory it seems to me that a drain is just another maintenance issue. Dave R.

I’ve been told that the water freezes as it gets to the door and past it so pretty quickly it isn’t able to drain away. And the better sealed around door for heat the less the water can drain away. First time building in the snowbelt so this is all new to me.

 

[smitty9999]

Buy a squeegee.

 

[Farmall450]

I’ve been told that the water freezes as it gets to the door and past it so pretty quickly it isn’t able to drain away. And the better sealed around door for heat the less the water can drain away. First time building in the snowbelt so this is all new to me.

Plus the seal will freeze to the floor on those real cold days and cause a world of hurt.

 

[mcbane]

Are drains necessary? Let the liquid drain to the overhead door and out under the door. Unless a drain is mandatory it seems to me that a drain is just another maintenance issue. Dave R.

My current garage slopes toward the door. When I park the bobcat with snowblower inside, the snow melts off the hot machinery and freezes as it reaches the door. The next time I need that machine I need to allow time to use a wonderbar to pry the door open because the gasket is solidly frozen to the floor.

 

[aventino68]

I'm torn between sloping towards door with a drain inside that runs all the way across, versus sloping 4 ways to a drain in the centre. Either way I'll have keep it flat in the areas not under the car so I don't have issues with any tool chests or benches.

 

[59 wagon man]

water will run downhill no matter what the pitch. a 1/16" will get water flowing. after all your not moving any waste products just water. plus to much slope will be a pain in the **** when jacking the car up and setting anything level.

 

[aventino68]

water will run downhill no matter what the pitch. a 1/16" will get water flowing. after all your not moving any waste products just water. plus to much slope will be a pain in the **** when jacking the car up and setting anything level.

That's got me thinking maybe split the floor into work areas that are flat and wont have any drains and other bays that have winter cars parked on them that have the drains for melting ice or snow.

 

[Cougar]

Plus the seal will freeze to the floor on those real cold days and cause a world of hurt.

Had that happen.
Pushed the button, door didn't open. Pushed it again, opener tore all the brackets off top of the door.

 

[59 wagon man]

maybe then a trench drain or two will minimize the pitch. you can have a 20' trench drain on either side

 

[Chris705]

I installed a trench drain across my center bay. It is 12’ in from the OH door. I pitched 8’ out (screed length) at 1/8” per foot by setting my trench drain frame 1” lower than rest of floor. If I could do over I would extend out another 2’ to 10’ on each side of trench to direct more snow melt into the trench. Today some trickles away from trench and puddles in front of car when I pull it in. Talk thru your thoughts with your masons, water will puddle if you try to place concrete at less than 1/8” per foot. It may even puddle when placed at 1/8”.... but I would create the pitch directly underneath the vehicle footprint or wider if your planning on having two DD’s parking side by side. I ran my trench to a Schier oil/sand trap..
I have plenty of flat areas away from the car for tool boxes. I also jack my DD and use a floor creeper w/o any problems when parked over the trench.

 

[DFB]

Had that happen.
Pushed the button, door didn't open. Pushed it again, opener tore all the brackets off top of the door.

 

[88carrera]

An 1/8” per foot is the minimum but you will still be left with bird baths due to the difficulty in getting a sloped surface perfectly flat. A 1/4” per foot would be better. You can get rid of most of the water but it’s pretty difficult to eliminate all of it. It’s still a lot better than the alternative of water running everywhere.

My preferred method of installing a floor drains is to place one in the center of each parking area. Set the drain an inch and a half low ( be sure to slope you sub grade accordingly to avoid thin spots in your slab). In a 10 x 20 area, this provides a little more than a 1/8” per foot the long way and 1/4” per foot across. The water drains back under the vehicle and the walking/working areas around it remain flat.

+1. I was limited to roughly 1/8" per foot slope in my repour and get puddling and generally little movement of snowmelt. This is undoubtedly exacerbated by a heavily textured/flake epoxy floor coating in my case, but if I could dictate slope I'd go virtually flat at the back where the shop stuff is and 1/4" slope where the cars are. A trench drain would be ideal as my melt either freezes at the door seal or just outside on the driveway.

The "Moerman Commercial Professional Heavy Duty Floor Squeegee with Threaded Handle Connection, 30 inch" I picked up from a popular online retailer does a fantastic job of pushing the water around when needed. Recommended.

 

[maxpat82]

in y "4 car" garage.. I only sloped one bay to a center drain 1/8 per foot...everything else is level.