snydes
Active member
How much of a grade (not sure if that is the correct term) would you use when digging in garage floor drains? How deep should they be?
Thanks,
Steve
Thanks,
Steve
Question on digging for a floor drain...
- Thread starter snydes
- Start date
larry4406
Well-known member
Make sure that the pipe slopes 1/4 inch for each 1 foot of run. Also make sure that your pipe is fully below the slab so you locally don't thin the slab thereby weakening it.
I have not put one in a garage, but you may want to think about a pee-trap, a screen/grate, and making sure the slab surface is pitched to the drain. When putting in floor drains in house basements, my plumbers used either 2 or 3 inch pvc with a pee trap. My preference was the 3 inch drain. The plumber provided a adapter that slipped over the vertical pipe with a slip fit. When the concrete contractor finished the slab, he would raise/lower the slip fit adapter so that the floor was pitched correctly. Afterwards, the plumber would snap off the excess pipe, trim it neat with the inside of the adapter, and snap on the grate.
Not sure where you plan to connect the drain but I would not connect it to the sanitary if I were on a septic system. Not sure what the Code in your area will let you do with the drain discharge.
I have not put one in a garage, but you may want to think about a pee-trap, a screen/grate, and making sure the slab surface is pitched to the drain. When putting in floor drains in house basements, my plumbers used either 2 or 3 inch pvc with a pee trap. My preference was the 3 inch drain. The plumber provided a adapter that slipped over the vertical pipe with a slip fit. When the concrete contractor finished the slab, he would raise/lower the slip fit adapter so that the floor was pitched correctly. Afterwards, the plumber would snap off the excess pipe, trim it neat with the inside of the adapter, and snap on the grate.
Not sure where you plan to connect the drain but I would not connect it to the sanitary if I were on a septic system. Not sure what the Code in your area will let you do with the drain discharge.
Nowadays I don’t think any jurisdiction will let you hook a private garage drain to their sanitary system. They are too afraid of anti-freeze and oil getting dumped. I wouldn’t do it into a private septic system for the same reason.
That leaves you with what they call a “drain to air” system. That means the end of the pipe just dumps onto the surface somewhere.
It is for sure something you will want to check with your local inspector about.
In PA I wouldn’t put in a “P” trap. Too much danger of freezing.
In addition, if it is a drain to air there should be no sewer gas to come back up the pipe.
That leaves you with what they call a “drain to air” system. That means the end of the pipe just dumps onto the surface somewhere.
It is for sure something you will want to check with your local inspector about.
In PA I wouldn’t put in a “P” trap. Too much danger of freezing.
In addition, if it is a drain to air there should be no sewer gas to come back up the pipe.
I'm not sure which type of drain you are talking about.
most of the time when folks think of a "drain" in a garage, they think about a small round or square drain grate located centrally in the middle of the floor.
like this:
I installed a "trench" drain just inside of each of my garage doors. this way I can wash a car inside if I want and the water will follow the slope of my garage floor (required by my county) but exit via the drains before hitting my doors. this allows me to detail a car in the winter months inside in my warm garage without having to leave my door open for water to escape (and thus cold air to enter).
I used a premade drain system that has the proper amount of "slope" already built in so water runs right out. you install the top of the drain flush with or better yet, slightly below the slab surface and once water enters, it drains toward the exit immediately..
I used a high end product called "ZURN". they offer a wide selection of grates to go over the trench from cast iron to stainless and more. this is a commercial grade product. you might have seen these style of trench drains at your local gas station. at least around here, they put them in surrounding the pump area incase of a spill.
this is not my install, but here is a picture of an installed trench drain, but I have no idea what brand. mine looks slightly different:
Zurn brand is not cheap, but it is high quality. I have seen much lower grade, but also much lower PRICED trench drain kits with plastic grates at my local home depot or lowes.
BTW, mine is intended for soapy water, not oil and antifreeze, so it exits to "air" just outside my garage foundation wall. there are other options though.
more info at www.zurn.com
or just google "trench drains"
not sure if I used "flo-thru" or "perma trench". I think I may have used Z886 or possibly Z806. they have LOTS of products, and even more grate options depending on how much you want to spend.
hope this helps. sorry for the long post.
good luck.
-chris
most of the time when folks think of a "drain" in a garage, they think about a small round or square drain grate located centrally in the middle of the floor.
like this:
I installed a "trench" drain just inside of each of my garage doors. this way I can wash a car inside if I want and the water will follow the slope of my garage floor (required by my county) but exit via the drains before hitting my doors. this allows me to detail a car in the winter months inside in my warm garage without having to leave my door open for water to escape (and thus cold air to enter).
I used a premade drain system that has the proper amount of "slope" already built in so water runs right out. you install the top of the drain flush with or better yet, slightly below the slab surface and once water enters, it drains toward the exit immediately..
I used a high end product called "ZURN". they offer a wide selection of grates to go over the trench from cast iron to stainless and more. this is a commercial grade product. you might have seen these style of trench drains at your local gas station. at least around here, they put them in surrounding the pump area incase of a spill.
this is not my install, but here is a picture of an installed trench drain, but I have no idea what brand. mine looks slightly different:
Zurn brand is not cheap, but it is high quality. I have seen much lower grade, but also much lower PRICED trench drain kits with plastic grates at my local home depot or lowes.
BTW, mine is intended for soapy water, not oil and antifreeze, so it exits to "air" just outside my garage foundation wall. there are other options though.
more info at www.zurn.com
or just google "trench drains"
not sure if I used "flo-thru" or "perma trench". I think I may have used Z886 or possibly Z806. they have LOTS of products, and even more grate options depending on how much you want to spend.
hope this helps. sorry for the long post.
good luck.
-chris