I want to make one bay of our two car garage into a woodworking shop and leave the other for my wife’s car. Unfortunately, the concrete slab in the garage is pretty much level with no floor drain. I plan to insulate and heat the garage so I need to get rid of the water so I don’t have excess moisture rusting all my tools. I live in northern Connecticut so the water is primarily melted snow, maybe a gallon or two at a time.
I have three questions. 1. What is the best way to get the water to drain to one place? 2. Should this be a central floor drain or towards the door? (How does water sloped towards the door actually get out without letting lots of cold air in?) 3. Assuming a central drain, what is the best way to make it? I do not want to remove and replace the existing slab.
For the draining part I thought I could build up the floor in the one bay with concrete (or something else?), all sloped to the center but I don’t know how thick would this have to be so it doesn’t crack and/or flake off? Or would it be easier to use a concrete saw to cut a whole bunch of sloping channels towards the center?
For the actual drain, I was thinking of cutting about a 1 foot square in the middle of the floor, digging out was much as I can, and then filling it with gravel. Or maybe making a concrete well with a sump pump would be better.
Any thoughts?
Replies
Without a slope running towards the drain how will the water get there? From my limited observations water runs downhill freely, all other directions it needs help. :)
My bet is that you already have a slope running towards the GDs. Once the water gets there it basiclly seeps under the door seal.
Without pouring a new slab, I'd go with a fan and dehumidifier as well as heat to slow/stop the condensation on your tools.
Having parked a car full of snow in the garage a number of times this winter and watching where the water went, I can tell you that, if the floor is sloped at all, it is away from the doors. About 1/4 of the water stays under or around the car and the rest barely pools in about 6 spots covering maybe 30 sq ft. I was trying to think of some clever way of adding a slope easily.I've tried the fan method but first sweeping what I could out, leaving the doors open, and two fans running, it took 1/2 a day to dry the floors at 35°F. If I had some some sort of small dam to contain the water and a heated shop, a dehumidifier might work.
CHECK IF IT'S EVEN LEGAL.. IT'S NOT SAFE!
(says the man with a floor drain <grin> )
I didn't know it was illegal. So I guess that leaves draining the water towards the door. Could I do this by adding concrete or something else on top of the existing slab?
It's not legal to put a drain in any residential
garage unless you had the permits when it was
constructed & put the drain in then. However,
I don't know of anywhere where you could even
get a permit.
Its not legal to put a floor drain in a garage? Seriously?
Its done here all the time
In most parts of the country the fear is that a garage
drain could be connected to the sewer or septic system
which is not legal. If, and this is a big if, you could
get a permit, you'd have to construct a separate catch
basin that could be pumped & cleaned out, with provisions
to haul the "hazardous waste" away. Granted, this was done,
(garage drains) years & years ago. It's not done anymore.
To drain to a basin "in and under the garage is dangerous",
and should not be done.
A floor drain in the garage usually requires a triple basin to separate out the oil and gas. The issue is keeping oil and gas put of the sewer system. In the case of a sanitary sewer it will disrupt the "bugs" used to break down the seweage in the treatment plant. In a storm water sewer it will put the petroleum products back in to the ground water, which is highly undiserable.
hyder - I've done exactly as you describe, except with a new 6" slab in my renovated (c. 1932) 3-bay garage. Negotiated with the building official - dead flat for workshop part + one bay, pitched to center trench drain (about 6" x 6" cast iron grate, PVC box) and taken out the back with PVC pipe to a bronze grate in the stone base of the garage.
A floor drain in a commercial garage to grade would have to involve an oil separator, but I don't see any problem with a drain to daylight which is what I have (not to sanitary or storm systems).
Jeff
Edited 3/15/2009 11:13 pm ET by Jeff_Clarke
Starting with a level floor, the only realistic solution, IMO, is to cut in trench drains with grates on top. Place them right under where those big gobs of ice form behind the wheels of your vehicle.
And buy a 2'-wide floor squeegee.
AitchKay
How about opening a hole in the garage floor, approx centered under wife's car. Place a container in hole (I'm thinking 5 gal bucket, but another size might be better) with a grate over the top. Find a grate that will prevent your tools from falling thru, and strong enough to support your weight, plus some safety margin. Seal up the edge of the hole to the bucket, so water flows to the bucket, and doesn't seep under your garage floor too much.
When the bucket collects water, suck it out with shop vac.
This is a little primitive, but seems practical to me.
I like the idea of a bucket in a hole. I had thought of something like that with a sump pump in it but with a shop vac you get to see what's in there instead of just automatically pumping it into the backyard. Maybe even simpler would be a removable bucket that I can just dump outside when it's 1/2 full.Does anyone think adding a couple of inches of concrete, sloped towards the door, would work?
Sham wow!