Slope for garage floor

[Kevin54]

Before they ever pour the floor, if you are going to have slope to it, what the concrete guys do around here is snap a line on the foundation and drive a few pins in to hold grade.

What you may want to do, and I forgot to tell the guy that did mine, is to make the corners a little higher and slope the floor from the corners to the door. By that I mean that you will have slope back to from, but you also need a slight slope from the side to go towards the door. If they don't, I can almost guarantee water will run to the corners instead of out the door. Also, if you are going to have control joints cut in, have them cut in a way that water will stay between the door opening and not run to the front foundation.

 

[TOOL_MONGER]

ahhh.. I guess you're a building inspector? I'm sure it's the same no matter where you live, the code book lacks a lot of common sense.

Not a building inspector but i did stay in a holiday inn express the other day...

 

[concerned vern]

completly off topic, but related question: why does the garage floor need a slope? i understand for water to flow out, but what water?!? i have a 1 car attached that is 20 ft deep and has about 4-6" of slope from front to back. i would imagine washing the car in the garage would soak the drywall and lead to mold. i dont have a washer/dryer or hotwater heater in the garage. am i missing something? thanks for humoring my tangent.

Funny, you must live without SNOW!!! Snow clings to the vehicle and voila! I have a shallow swimming pool in my garage in the morning. My issue is that the garage pad is not sloped therefore I am pushing water with a broom every morning to get the water to the drain, pain the *** and the garage floor never gets dry in the winter.

 

[Doozer75]

My garage slopes 6" in 20 feet.
I am ready to hammer the sum ***** out
I hate it so much.
Pour it level, or very close to level.

-Doozer

 

[wssix99]

The codes require the slope because of gasoline. It has nothing to do with water or snow melt.

(Cars, lawn mowers, gas cans, etc.) In the even of a spill or a leak, the slope takes the fumes, which are heavier than air, to the doors and out of the buildings. Without this, the fumes will linger, in an explosive state and in an enclosed space. (This is a bad thing.)

You'll also see folks here who have municipalities that specify codes for garage floor drains, requiring them to drain out to air/above grade. This is for the same reason. The fumes need to fall down, out, and away. (And not get trapped in the pipe/trap.)

 

[gdh33]

FWIW both my garages are sloped. Newest one is 2" over 40' and it was done well and have no standing water, except one low spot 2' by 2' maybe 1/8 deep. Very happy and that is why they slope the floors. As others have said, having a drain can be a real pain in the **** when you pull permits. Easier to just slope the floor. I have yet to have my garage door freeze to the pad in the winter and it is 16' wide. I do get a bit of ice damming at the door as it is unheated (attached) but i chip that out once a year or if it gets sunny and warm it melts on its own.

Slope on new garage was created with the crushed stone and pad is equal thickness.

 

[PhantomEB]

4" over 24', not so bad yet but I haven't gotten tools or the project in there yet.