View Full Version : Help with floor grade/slope

05-02-2014, 04:52 PM
Please make recommendations: What is a minimum floor grade for a 40' x 36' space with cement floors and a grated trench drain down the middle/center (running the long way)? (I.e. what should my slope be over 18' to a Polydrain?)

I want to make sure the space will be sanitary and stay dry, but also don't want too much of a slope as to have tanks at a dangerous angle or things rolling around.

Ted Briggs
05-05-2014, 06:43 AM
.25 inches per foot. IMHO

05-05-2014, 07:03 AM
3/16" per foot is adequate, 1/4" is great.

dick murton
05-05-2014, 11:16 AM
The best drained / easiest cleaned floors I have come across were considerably more than 0.25" per foot - possibly even double that, with low slip tiles and epoxy grouting. It wouldn't have been much use for rolling kegs around, I agree (FVs and MVs only, and separately a plate and frame KG filter room), but drained well, so was easy to clean. Personally I would try and get more than one drain installed - to suit the layout of your plant so the drains are more or less below areas where spillages are likely, such as manual connections on FVs. You will save a lot of time and water washing down.

Ted Briggs
05-06-2014, 06:32 AM
Thanks Dick, I should have said .25"/foot minimum. Also remember That you cant pour from zero up, the thinnest part of the pour needs to be 3-4" and incorporate wire and re-bar support. So over 18 feet the end thickness will be 8"+ thick
"to have tanks at a dangerous angle" all tanks should have leveling feet so thats not a problem.

06-04-2014, 09:17 AM
We just poured our new slab last week. We used a 60' drain and 25' drain for +/- 2300 SF. The plans called for 1/4" slope, but the contractor asked if 3/8" would be ok since the framework would create that without having to rip any boards. We're very pleased with how it turned out.