Trench Floor Drain In Concrete

[StefanNH]

Anyone have any recommendations for trench drains in a slab? I'm setting up mine now to be poured and wondering what brand/ system to go with. Obviously since they are poured into the concrete I get one shot at this and want to make sure I'm going with the best option.

Also, It occurred to me that if I'm pouring a 6" slab with a 4" floor drain right down the middle wouldn't that make a 2" weak point right down the center?

 

[willymakeit]

Do a mud slab under your drain[assuming it is a plastic trench drain] leave enough area underneath to get some concrete under it also.
Mud slab allows you to use rods or rebar to set top elevation of drain with floor.
I assume you are using sloped bottom drains.
Do this in commercial work all the time

 

[TurnipTruck]

Might be cheaper to fab your own form for a trench drain.

 

[matt_i]

From researching it some, you have to define your "class of use" to select the grating...in other words there are heavy duty uses like loaded cushion tired forklifts and 747 airplanes which might have to cross a trench drain.

My interest was going to be outside due to part of the drive back-sloping to the shop area and I do wish to generally drive forklifts over it, although for the very heaviest uses I can use overlaid steel plates to distribute the load. I was going to form and pour the bottom surface of the trench with the down-slope built in, cure, then pour the sidewalls (which are likely going to get taller and taller due to the bottom slope, and finally finish with embedded angle iron(s) for supporting the grating and prevent chipping on the outside corner. Then the rest of the flatwork to match slope to the existing edge of the trench. The outlet piping has to also be routed, sloped, installed and set. With level land you might need a catchment sump.

I believe there are trench kits which have pre-molded sections that one snaps together and then pours the flatwork to match. Not sure how they deal with the internal slope or if its not really an issue, just reliant on more major water depth arrives to induce flow. Theoretically the trench could be closed-ended with no outlet.

I have a shop which has a bay with a central square drain and I have considered breaking it all out to get back to a level slab. Tool cabinets have to be shimmed to keep the drawers from auto-opening and I have to avoid the sinking into the weak grating when moving machinery. My use isn't typical but worth considering how you intend to use it.

 

[shade]

Here is what I went with for my build. You can see pictures in my build thread

Garage West to Midwest and a toy barn build

Hello all, Ryan. I have enjoyed so many threads people have shared so I wanted to give back. Here's my journey! Been in AZ my entire life and our last house was a typical suburban place with a 4 car attached. It was a new build which is rare so we jumped on it in 2019. I work in CyberSecurity...

www.garagejournal.com

 

[StefanNH]

From researching it some, you have to define your "class of use" to select the grating...in other words there are heavy duty uses like loaded cushion tired forklifts and 747 airplanes which might have to cross a trench drain.

My interest was going to be outside due to part of the drive back-sloping to the shop area and I do wish to generally drive forklifts over it, although for the very heaviest uses I can use overlaid steel plates to distribute the load. I was going to form and pour the bottom surface of the trench with the down-slope built in, cure, then pour the sidewalls (which are likely going to get taller and taller due to the bottom slope, and finally finish with embedded angle iron(s) for supporting the grating and prevent chipping on the outside corner. Then the rest of the flatwork to match slope to the existing edge of the trench. The outlet piping has to also be routed, sloped, installed and set. With level land you might need a catchment sump.

I believe there are trench kits which have pre-molded sections that one snaps together and then pours the flatwork to match. Not sure how they deal with the internal slope or if its not really an issue, just reliant on more major water depth arrives to induce flow. Theoretically the trench could be closed-ended with no outlet.

I have a shop which has a bay with a central square drain and I have considered breaking it all out to get back to a level slab. Tool cabinets have to be shimmed to keep the drawers from auto-opening and I have to avoid the sinking into the weak grating when moving machinery. My use isn't typical but worth considering how you intend to use it.

I won't be rolling any 747s over it but will have a lot of heavy/ tracked machinery. Was considering going with steel with a slight slope on just the front section of the shop.

 

[finn]

Not sure on what the rules are, but the guy who built my larger shop was required by the Health department to install an oil and grease separator when he built an shop and installed a couple of site built trench drains.

At about the same time, I built a smaller shop a mile away, in the same township, but we used the plastic trench drains commercially available at Menards, etc. We didn’t need an oil separator.

The one we built was 1728 SF, the one that required the separators is 3600 sf, although it was built in stages.

It may be that he was running a business at the time, and I wasn’t.

There’s no zoning in the township, but the state regulates wells and septic systems

 

[Dig Doug]

Lots of options to make a track drain work
weld up a ring and grates
write a check


Set this up for a Buddy

Then he used pavers for the driveway
each segment of drain has fall built into it = Top Grate is level ! The flow line has a slope built in each drain section

 

[StefanNH]

Lots of options to make a track drain work
weld up a ring and grates
write a check


Set this up for a Buddy

Then he used pavers for the driveway
each segment of drain has fall built into it = Top Grate is level ! The flow line has a slope built in each drain section


I like that system, I think that's what I'm going to go with.

 

[StefanNH]

Not sure on what the rules are, but the guy who built my larger shop was required by the Health department to install an oil and grease separator when he built an shop and installed a couple of site built trench drains.

At about the same time, I built a smaller shop a mile away, in the same township, but we used the plastic trench drains commercially available at Menards, etc. We didn’t need an oil separator.

The one we built was 1728 SF, the one that required the separators is 3600 sf, although it was built in stages.

It may be that he was running a business at the time, and I wasn’t.

There’s no zoning in the township, but the state regulates wells and septic systems

Code Inspector told me not to worry about it and just to drain to daylight. We tend not to get the state involved out here haha.

 

[firebirdparts]

I formed up my own. All the systems you can buy looked really pitiful to me. Plus you can't slope them. They have to follow the floor. If you make one, the top and bottom can be doing separate things.

I have a lot of work in my grates, but I think there's some workarounds. They make some ramps that looked like a bargain if you wanted to form your drain up to fit the ramp.

I dug a few postholes and put concrete and rebar in there to tie to down to. Something has to hold it down.

 

[Fav Onefour]

What is the total length on your planned drain? The pre sloped versions do have max length.

Look at load ratings before selecting a drain assembly. I'd also scrutinize the grate assembly and how easy it is to remove. I harp on the subject a lot, but trench drains collect stuff. It's a fact.

Most drain manufacturers have specs listed online for the required trench and concrete surround. They are quite specific.

Sloped slabs are great for drain areas. They are a pain for some basic shop functions. If possible, try to do a flat section for your work and tool storage. I don't know the size of the shop. Is it big enough to park vehicles in the drain section and still leave enough room for a work area?