Opinions on floor drains.

[75slant6]

Hello everyone. I’m looking for opinions on shop floor drains. My initial plan was using 4 12x12 basin drains (marked by the red circles) but I’ve been debating if I’d be better off doing two long trench drains (blue) or maybe a trench drain on the right and the basins on the left. For a little more info on the planned layout of the shop the top right corner will likely be where I park my truck, so I’ll definitely want a drain in that area. I’ll be installing a 2-post lift (yellow) and don’t want any type of drain directly under it for any spilled oil to run into or to interfere with the wheels of a oil drain pan or engine hoist which is why I have the basin and/or trench drain stopping short of the lift. I would still slope the lift area floor toward the drain, that way if I want to wash out the underside of a vehicle on the lift, it’d drain out.
For the left side of the shop, I’ll also eventually be buying a movable 4 post lift which will probably be in the top left section of the picture and a rotisserie in the bottom left corner. Any body/paint work I do will likely be in the bottom left corner as well, so having a drain there will be nice to be able to wet the floor down before painting to keep dust to a minimum.
I did already buy the basin drains but have been having second thoughts and may take those back.
Thoughts?

 

[BillK]

First thing to do is find out if they are even legal in your area. Around here you cannot have them, at least not without an expensive grease trap system.

 

[75slant6]

First thing to do is find out if they are even legal in your area. Around here you cannot have them, at least not without an expensive grease trap system.

No inspections whatsoever here for residential shops.

 

[75slant6]

I edited the original post to add more details/info

 

[tarmy]

I am in snow country with a tractor. No drain…get a push broom style squeegee. The cost, hassle to keep clean and not stinky as well as unclogged or a dry P trap makes it too much for me. Never thought twice about it after I built my shop/garage.

 

[Leaflessshadetree]

I never asked for or wanted any floor drains. I wanted a flat floor, IMO it's just as easy to squegee water out the door as it is to push it to the drains.

 

[BillK]

No inspections whatsoever here for residential shops.

Thats fine but where is the drain going to go to ?

 

[wssix99]

Aside from the legalities and concerns about what goes down the drain and what happens after that:

Drains in the center of a concrete floor cause cracking. Therefore, you will need to place saw cut joints radiating outwards in crosses from the drains to control the cracking.

A 2 post lift will need to be minimally spaced away from these joints. From the looks of the drawing, the posts are too close to the drain and the cuts that will need to go around it.

Due to the size of the garage, you may need another saw cut joint between the drains. This cut may also be too close to the posts.

Lots of headaches here. Putting trench drains at the door and sloping the floor towards to the doors (or skipping the drains entirely and just letting everything drain outside) avoids a ton of headaches. (Having a 2 post lift and several 4 post lifts, I would also skip the 2 post lift entirely. Lots of other threads on that, too.)

Either way, you should be planning your saw cut joins with your concrete contractor first. (Otherwise, you could have unfortunate surprises when you go to place the lift.)

 

[BombShelter]

What are the drains for, rain/hose water or for catching car fluids?

I've been in a ton of garages and we used to pour lots of garage floors, I have never seen a drain in a modern home-owner garage. I have seen trench drains at the doors to keep outside water from moving in.

Personally I wouldn't mind some sort of trench drain, up here a car can hold 5+ gallons of snow that melts on the floor.

 

[75slant6]

What are the drains for, rain/hose water or for catching car fluids?

I've been in a ton of garages and we used to pour lots of garage floors, I have never seen a drain in a modern home-owner garage. I have seen trench drains at the doors to keep outside water from moving in.

Personally I wouldn't mind some sort of trench drain, up here a car can hold 5+ gallons of snow that melts on the floor.

Drains would be for snow melt, rain and the occasional washing of a vehicle. That said, I’ll be putting heat in the floor, so snow melt and rain will evaporate pretty quickly in the winter

 

[LiketoFix]

That's because Modern home-owner Garages are cheaply built and it costs $$ to do it!
Us old school guy's always did it the right way with Floor Drains! JMO!!!

LtF

 

[75slant6]

Thats fine but where is the drain going to go to ?

Daylight

 

[65ranchero]

I have added another 2 car garage of my current one and it has a 7k Mohawk 2 post in one bay and the other bay is empty .
When I was planning it I added radiant heat and a 4" cast iron center floor drain where the floor slants always to the center at a rate of 1/4" to 3/8 in 10'
While the grading was being done before the pour had the excavator also ditch from the drain center to a near by drainage ditch (to daylight) so that 4" 3034 green pipe could be run.
It give me the opportunity to wash inside ( but I never do) but it is mostly for the SxS and the snow blower to drip dry

 

[TurnipTruck]

This panoramic of my 40x60 shows the sawcuts defining my shop into thirds. The left and the middle are flat, with the right third sloping one inch in twelve feet down to a 28’ trench near the big doors.
I cover the trench with bar grating, and pump all the snowmelt out a couple times a winter.

 

[jack stand]

I appreciate my floor drain for your same reasoning, although I've never washed a vehicle in it like I envisioned. It's very nice to melt down a snowy vehicle or other winter toys.
I just ran a 2" pipe to the outside where I have a 32' deep lean to the whole length (no rainwater) into a deep hole with a deep layer on 3-6" loose rocks, filter cloth on top and backfill to grade. I figured that it would have at least 9 months to dry out if necessary and no worries about critters eventually giving me trouble with a daylight pipe.
I've never had a hint of overwhelming it in 15 years, but I knew that I have well draining sandy soil.
My other bays I wanted a dead flat and level floor for fabrication and machine tools.

 

[zkdiesel]

Seems like a lot of drains either way. I’d do one in your primary melt off spot/washing area

 

[75slant6]

Seems like a lot of drains either way. I’d do one in your primary melt off spot/washing area

You may have a good point there. Might just have to do a trench drain parallel with the doors and slope the first 20’ toward the door.

 

[75slant6]

This panoramic of my 40x60 shows the sawcuts defining my shop into thirds. The left and the middle are flat, with the right third sloping one inch in twelve feet down to a 28’ trench near the big doors.
I cover the trench with bar grating, and pump all the snowmelt out a couple times a winter.

Do you have the shop built now and how do you like this setup?

 

[Leaflessshadetree]

First thing to do is find out if they are even legal in your area. Around here you cannot have them, at least not without an expensive grease trap system.

It's been about 10 years since I checked but I recall the trap being slightly over $100. Doesn't seem expensive to me if someone wants the drains.

 

[75slant6]

It's been about 10 years since I checked but I recall the trap being slightly over $100. Doesn't seem expensive to me if someone wants the drains.

Unfortunately the cheapest premade grease/oil trap I could find is closer to $1000 now. There are ways of building your own but I spoke with our local plumbing inspector and floor drains can be run to daylight without issue.

 

[TurnipTruck]

Do you have the shop built now and how do you like this setup?

You could click my link below, if you have an hour to squander.

 

[LS6 Tommy]

First thing to do is find out if they are even legal in your area. Around here you cannot have them, at least not without an expensive grease trap system.

X2. Floor drains in a garage are a BIG No-Go in NJ...

 

[Rc_Guy]

I never asked for or wanted any floor drains. I wanted a flat floor, IMO it's just as easy to squegee water out the door as it is to push it to the drains.

Don’t know where you live because you don’t have it on your profile but not every state you can squeegee water out the overhead door when it’s 20 below zero

 

[75slant6]

I met with the concrete contractor this evening to go over options and here’s what we came up with. We’ll be putting a trench drain (blue) in 15’ from the doors and 6’ from either side wall. The first 30’ of the shop will all drain toward the drain, the remainder of the shop will be flat. He also has a 40x60 shop and he later his out very similar, other than he did his drain at 20’ and sloped the first 40’ and left the remaining 20’ flat and he really likes it laid out that way.

 

[wssix99]

Did you talk about the layout for your control joints? With that layout, they are going to fall naturally where your lift posts are and you'll need them far away from the posts. This is not a problem - you can add more joints to space them properly, but you'll want to have them planned and laid out ahead of time on your floor plan.

 

[Mainiac Mat]

I considered a floor drain. I was told that there was a standard oil trap that I could purchase and install, but at the end of the day, I didn't want to delay construction fooling around with it. So I joined the squeegee club.

Snow melt off the vehicles is pretty substantial up here in Mainiac land, and the biggest "problem" has been condensation on the transom windows over the OHDs.

I thought it would be cool to wash the cars indoors in the winter, but at 30'x26', I don't think it's big enough to do that without spattering water all over the place.

 

[mrhemi426]

I put legal, inspected floor drains in my 3 car attached garage (SW Ontario) when we built the house. Connected to the storm sewer, not the sanitary sewer. Purpose was more for snow melt runoff during winter. I ended up plugging them a year later due to bad odour periodically. I now have a car mat under the vehicles that get driven in the winter instead. Squeegy out the door when required. Drag the whole mat outside in spring time and give it a good cleaning outdoors. Wish I never installed the drains in the first place.

 

[75slant6]

Did you talk about the layout for your control joints? With that layout, they are going to fall naturally where your lift posts are and you'll need them far away from the posts. This is not a problem - you can add more joints to space them properly, but you'll want to have them planned and laid out ahead of time on your floor plan.

We didn’t discuss the saw cuts but the lift will be 3-4’ past where the sloped floor will end and past the saw cut

 

[finn]

I have had a variety….

Catch basin with grease trap. Cons: mine are trip hazards, maybe because the grates aren’t completely flush, any dropped fastener immediately falls through the grate, welders, carts, toolboxes etc don’t play well with the grate, and finally, it makes it difficult to locate a two post lift or move a four post lift, or even an engine lift, and, finally, floor sweepings, oil dry, etc. end up in the drain….Summary: would not recommend.

Trench drain. Cons: floor sweepings end up in the drain, and loose fasteners hide down there, but the plastic grate on mine don’t pose much of a trip hazard or rolling toolbox issue. Possibly because they were installed correctly where as the catch basin in my other shop wasn’t. Summary: Easier to live with than the catch basin with separator.

Small circular drain with trap: Cons: mine was in an unheated garage and the trap froze regularly by January and didn’t thaw until late May. Also caused problems rolling things like floor jacks, boat trailer jacks, toolboxes, etc. Summary: wouldn’t recommend.

Slope towards doo: Cons: complicates installing cabinets, etc since everything must be shimmed, complicates lift installation. Summary: probably ok if slope is minimal.

Flat floor: cons: drainage is compromised, but in floor heat addresses that. Summary: best option with a heated floor. Easy to clean, no trip hazard or issues with rolling equipment

 

[LiketoFix]

Thats fine but where is the drain going to go to ?

Where does code tell you to tie them into?
Storm? Sanitary?
If you have neither, French Drain?
LtF

 

[SteveL]

I have a floor drain in the center of the single car bay of an oversized three car garage. If I were to do it all over, I would have the entire floor sloped toward the overhead doors and add a trench drain running parallel with each door feeding in to a catch basin between the two. Drop a sump pump in it every once in a while and it meets code, at least here it would. This way any rain, snow melt or car washing water all goes to one spot.

Heres a link to what I would do:

 

[LiketoFix]

Opinion;
For me as I've stated before with 3 large Bays and all having their own Crock style old school Drains in the middle with proper drainage in each. As We pull our vehicles into either Bay from outdoors weather it's Snow, Rain, etc.............It's never a problem as ALL water Drains accordingly. Heated area dries and Problems Solved. Easy to control washing each Bay Down individually and Keeping Clean. When ever I want to get on a Mechanics Dolly and roll underneath or Lay a Floor Mat down,(cut piece of Carpeting), I throe a piece of Heavy Gauge 2'x2' Tin over the Catch Basin and never drop anything into the Drain or Have a Problem Rolling over the Catch Basin. It's worked for me for over 40 years and I wouldn't have done it any other Way!
As a contractor I always gave the Customer what they Wanted in these situations and gave them different options on different benefits to each scenario including Cost's which usually dictated what they wanted. All depends what your wants and needs are.
Not everyone wants a garage to do work in as some just park their cars in.
Different Strokes!!!
LtF