Slope and drain/catch basin options?

[VietGnome]

Hey, previous thread got some traction when I was looking for help deciding on a grade plan for my shop. Decided on the rear "shop area" to be level, and have the front sloped towards the two front 10' wide doors to deal mostly with snow melt in winter, etc.

Some helpful people pitched the idea of a trench drain/catch basin to help with melt.

The main thing, is tying whatever I go with into a drain system is just not an option. Whatever I go with will need to be a simple catch basin style drain and I'll have to manually deal with it.

The three options I'm between are:

1. 17x17x24 catch basin centered under each bay, with concrete sloping in towards it. Most labor as grading will be more of a PITA for the concrete guy. Possibly the cheapest material wise (2x Catch basins with galvanized grate are around $375.)

2. Linear trench drain oriented perpendicular under each vehicle bay, same grading concept as above.

3. Linear trench drain parallel with door. Slope would be simple slope towards door, and drain would catch. runoff.

Second biggest concern with option 2 and 3 is the price of grade covers. I might have a bead on two 6" wide x 6' long stainless grates on marketplace for only $100. Outside of that, any new galvanized/stainless grate cover is insanely expensive. Looking at 600-700 minimum for 20ft of grate to cover off 2x 10' wide trenches.

I've looked at some catch basin style channel drains. The issue with those is they seem to be designed to tie into a drain system, so the often have a "U" shaped bottom are narrow, and somewhat shallow. So they'll fill quickly and be a PITA to clean. Such as https://www.homedepot.ca/product/re...t-with-portland-grey-grate-3-pack-/1001580791

I could possible tie a few kits above to a shared catch basin between doors for probably a $600-700 range all in, not including whatever that would cost in labor.

Looking for thoughts/input. Not sure if it not tying into a drain system will also cause issues with stink, or if a bare concrete trench will require some sort of liner/sealant?

The last option is just just keep the rear level, slope the front towards the doors. Doors are 10' wide so water shouldn't really pool against walls at all, and I also have an 8" stem wall all around, so there wouldn't be an issues with rot. Not necessarily opposed to this either.

 

[Bunsen Honeydew]

How about a concrete swale inside of the doors, draining into a sump pit? Somehow, I don't think you will be dealing with a significant volume of water at any single moment.
I picture a good amount evaporating before it ever reaches the drain.

 

[VietGnome]

How about a concrete swale inside of the doors, draining into a sump pit? Somehow, I don't think you will be dealing with a significant volume of water at any single moment.
I picture a good amount evaporating before it ever reaches the drain.

That could be a good option.

I also wonder if the majority of it would just evaporate, and be more of a pain in the *** to both have made, and lose things into.

I feel like just grading the front half to the door and a squeegee will be easiest solution.

 

[shade]

@VietGnome - I am actually doing this on a barn we are building.
We put in a trench drain. Roughed in before concrete. Concrete poured to slope as desired

 

[VietGnome]

@VietGnome - I am actually doing this on a barn we are building.
We put in a trench drain. Roughed in before concrete. Concrete poured to slope as desired

Looks good! How much were the metal drain covers? That seems to be the biggest expense here.

And do they drain somewhere or just hold water to be pumped out as required?

 

[shade]

The entire drain and grates was like 3k. Heavy guage steel and has a sediment trap that can be emptied.
It drains outside the barn no pump needed.

 

[Fav Onefour]

Is the space going to be heated continuously? Up north, those trap assemblies can be an issue if the building isn't conditioned.

Trench drains tend to need cleanout. If you go that route, it's worth planning on that fact. Make it a simple process.
The basin idea is pretty good. I've dealt with quite a few variations. Whatever version you use, it will also need to be cleared once and awhile.

Buddy has a sump basin in a four bay truck shop. He built a mini double pit. It's built to catch debris in the first pit and then overflow into the pump hole. The first pit has a flat bottom the width of a grain scoop and about three feet long. The bottom is about sixteen inches below the slab surface. He's able to pop the cover and clean it out in minutes. The sump hole stays clean if he remembers to clean the debris pit.

With a smaller shop, the initial sediment hole can be fairly small, but make it easy to clean. I'd plan that out before doing any concrete.

As far as drains go, I like to keep the drain under the vehicle parking spots. In my garage shop, I sloped each bay to the vehicle center and use a simple straight pipe into the drain system. It keeps the floor dry outside of where the vehicle sits. That's fine for my world, but everyone has their own idea of the perfect setup.
I'm simply biased against trench or channel drains unless they're needed. I have quite a few channel drains and I'm honestly tired of the work and hassle. It's surprising that no one mentions how many parts clang across the floor and drop in. It's a real riot pulling grates and digging in slop if you need the part.