I'm getting closer to having about a 30x30 shop built on some land I just bought. I want to be able to wash my vehicles inside in the wintertime. First I was going to put in a piece of grating and run a pipe to the outside. But talking with another builder he thinks that might just get clogged up over and over. He is suggesting a pit directly under the grating filled with gravel.


I have a 55 gallon drum that I can cut the top and bottom out of, then dig a hole, insert the drum sleeve, fill with gravel and cover it with a removable grate. I can weld up a frame to hold the grate, it's about 1" thick, should the frame have some tabs running off of it to help it stick to the concrete? And, is this a better way to handle the wash water?

 

that is a better way until the pit fills up. i would put in a drain and run it outside to a drywell like you planned on.
have the drain pit large enough to be able to clean it out if it gets full of crud. and leave access to the drain pipe so you can flush that out if it gets plugged up.

put the drywell outside the building where you can clean it out if you have to.
by putting the drywell under the slab once it is clogged you will have to bust the slab to maintain it.

 

Well, according to your signature you're located in Wyoming so you might not have much of a problem but here's something to think about:
The "gunk" that accumulates in the bottom of that dry well is considered hazardous waste (oil, grease, etc.) and you should have an oil-water separator ahead of your dry well. That separator needs to be sucked out by a licensed hazardous waste disposer.
As I said, in Wyoming you'll probably have no trouble with your idea - until you or your heirs try to sell the property.

 

I don't know why you're thinking that oil and grease will build up in the drain. It won't be any different than washing a truck in a driveway. I'm not going to be putting hazardous waste in the drain. I think he's worried about mud eventually filing it up, I live on a dirt road and drive down a lot of dirt roads. Maybe I should skip the gravel and just be able to shovel out the mud after some time.

 

exactly. once the catch pit fills up with dirt/sediment the only way to clean it is to get in there. if it is outside it is much easier to access to clean out.

 

Appears suggestion of drain w/ trap, has already been mentioned?? Thought perhaps system similar to a waste, or storm water drain with trap that required removing drain cover and occasionally clean any debris or sediment that accumulates in the trap?? Unless of course, intend using garage for working on heavy farm type equipment then perhaps more sophisticated system may be required??

 

Typical mud build up after a couple of rainy days

This is an example of the worst that happens from time to time. This amount of mud would be sprayed off outside of the garage first. Then the vehicle would be washed inside in the winter time but outside during the few warm months. The floor will only have a slope of about 3/8" over 15ft, so I don't think the remaining dirt will readily flow into the pit. I can shovel out any large amounts that are on the floor. If it builds up in the pit I can remove the grate and dig it out just like digging a fence post hole.

I don't have any large heavy farm/ranch machinery. I get everything done with homemade implements and an old 4X4. I only have 63 acres of natural prairie right now that I will be trying some over seeding projects on in the future. I was able to till, plant, and grow 5 acres of irrigated pasture before with my homemade devices. This will be a larger scale effort but there isn't any irrigation so the planting will be done differently. Currently we are building a fenced corral with a wind break to plant some apple trees, next year I will be attempting some over seeding.

 

I have 2 floor drains, each 14x14x14. 2" pvc enters thru a knock out in the side 3" from the bottom. So, I can have 3" of crap in the bottom before it gets into my pvc. The pvc runs to a dry well outside the garage. Hole was 48 inches deep, approx. 2-3' of gravel. I only wash the car or truck inside in the winter and knock off as much as I can before I bring it in.

 

I'm adding a 12x40 addition to my shop to live in. I plan to have a small kitchen that I will run the drain down the hill about 100 ft & not hook it to my septic system. It will only have dishwater in it so it's not toxic. I don't have to have the shop inspected only a home so I don't see any harm in doing it

 

So you'll only be washing clean dishes with plain water?

 

I'll be watering my blueberry bushes with the soap & water from my kitchen. I don't use any harsh chemicals on my dishes. I use the mildest detergent I can due to the fact the strong ones cause me to break out with a skin rash. I use free & clear laundry soap also for the same reason. I believe in using water in the best way. why not use it to water my blueberry bushes.It will never reach past my property line

 

Have you pored the floor yet? if not why bother with all this drain stuff at all, just slope it towards the bay door. Then when washing all you have to do is crack the door an inch and let it drain out into the driveway.

With the barrel idea why bother putting gravel in it, all the gravel is going to do is reduce capacity and make it harder to clean. Keep the barrel empty and make the grate easily removable. You then got up to 50 gallons or so of drain storage capacity. Easy to clean out, open grate and scoop, though I'd imagine you'd have to make the ideal tool. And finally easier to get into and search when you inevitably drop something like your keys in it.

PupnDuck has a point about chemicals, here and many other places it's actually illegal to wash your car in you driveway, they just don't enforce it. You'll eventually have some rather toxic dirt under your shop. If that ground water matters to you(a well) then you need to consider that.

Gives me an idea though, let's see if I can explain this. They make and they are rather cheap those oil/chemical absorbent pads often referred to as oil diapers. Make a removable grate/screen for the base of the barrel and put it on a chain. Place a pad or two on top of the grate and lower it into the barrel pit. This way the pad helps catch contaminants and to clean it out all you have to do is pull up the chain and swap out the pad.

If anything you'll want a layer of gravel under the barrel to help with draining.

 

Waiting on the daily rain to slow down or stop to start the dirt work for the concrete forms. The gravel will only be about 2" or 3" deep at the bottom of the barrel, that's to help stop erosion. I was over at a friend's place and he uses an old shirt under the grate to catch the debris. My grate is easily removable and I will take your and his advice to put a debris trap under it. I just finished welding the frame for the grate and it is a bit taller than the grate. That should allow enough room for a screen and a diaper like you are talking about.

To clean it out I can just use the same tools I use for digging fence post holes...I've dug plenty of them. I find that the dirt has a higher clay content about 2 ft. below the surface. So I think I might still run a 3" pipe out the side of the barrel in case I need to set up a leech field or tie it into the existing leech field.

I don't understand how I'm going to pollute the ground any more from the inside drain than I would from washing outside. Both times all the water will run off onto the ground. I don't live in a city so there isn't any sewer system or restrictions on washing a car.

Someone recommended a slope of 3/8" over 15ft. He said that was enough to help squeegee the water into the drain and still be able to level tables and things.

 

What i plan to do is use a plastic 55 gallon drum as my sump, have a sump pump with a level float. Before pouring concrete, install a 2" pvc pipe from the sump on a slight incline to just before the footing then an elbow and riser so it sticks out from the floor. When washing vehicles, hook up a hose to the pvc riser and send the water to my septic tank or the ground. When the sump pump stops after the sump is empty, the remaining contents drain back to the sump.

 

I imagine it gets a bit chilly in the winter where you live. Watch out for the water in the sump freezing and taking the pump with it.