Code (IRC 2003 R309.3) calls for garage floors to slope toward the main vehicle entry door. That section doesn’t call out how much slope. Is a minimum specified somewhere else? And what is “typical”?
I plan to use the attached 2 car garage as a shop for my woodworking hobby, so I want to both meet code and be safe but also have as little slope as will satisfy those requirements. I don’t think it makes a difference, but the slab will have radiant heating imbedded in the concrete.
Replies
The last garage I built all sloped toward the middle of the garage in to a trench drain.
Is this an option for you?
We did an 1/8th per foot as I remember.
jeremy
The bad news is you've done exactly the right things to be exactly where you are today.
"IdahoDon 1/31/07"
1/8"/foot.
SamT
Praise the Corporation, for the Corporations' highest concern is the well being of the public.
We go with a 4" slope on garages.
On my 36' deep garage, I went flat on the back half, and sloped 1" on the front. I don't yet have a door on it, and haven't pulled vehicles quite as far in as I probably will when I'm finished, but water does generally go where I want it. There is a very slight puddle near the exit - I might end up grinding a little bit to make sure it doesn't accumulate and possibly freeze under the door.
My concrete finisher recommended going with more slope, but like you I wanted it as flat as reasonably possible. He did a pretty good job keeping a relatively flat plane. Steeper slopes are less likely to leave puddles in the inevitable dips left from finishing - unless you've got a finisher with a fancy laser screed.
Don
Actually you could use metal keyway forms as screed runners, and get it really true to whatever design you want. The only limit is how wide of vibratory screed you have.
Check out: http://forums.taunton.com/tp-breaktime/messages?msg=88813.53&redirCnt=1
for an overview of what I'm talking about. I've seenthem used on a couple of warehouses, and a bus maintenance barn. They seemed to work really well, and when you figure the cost savings of not stripping the forms are cost effective.
1/4" per foot.
are you drunk? 6" slope on a 24 ft garage? everything that would move would have to be chocked to keep it inside
p
Edited 4/25/2007 10:17 pm ET by ponytl
I've seen about 2" over the length of the garage (about 25 feet or so) as typical.
Make sure the corners by the garage door kick up a bit to direct water to the door instead of funneling it to the inside corners.
We average about 4", but our inspectors won't even measure as long as they can see that it is sloped.
dug