Bathroom Install in Existing Garage

[bad_idea]

I am kicking around the idea of installing a bathroom in my garage. Building is complete with 6" slab, cinder block stem wall, and 2x6 studded walls. Thinking of building a false floor about 1' above the concrete slab and routing the drain piping in that void space. Punch the drain line through the cinder block of the wall. Would then install a tee on the outside with a clean out on the top and then a 90 below grade running to the septic tank 25' away.

I understand freezing could be an issue, but can deal with the line freezing as long as it doesn't damage anything or impact the septic tank. It doesn't freeze often here and if it is below freezing then I probably won't be out in the garage.

Thoughts?

 

[Slowgsr]

Could get a composting toilet for #2 and drain anything else to a French drain, be sure to use all biodegradable cleaners.

 

[wirt]

I put an addition on my garage two years ago for a bathroom, best money I've ever spent. Lol

 

[rsanter]

If you come out of the building and drop down, plus insulate the elbow and clean out part then you won’t have as much an issue with freezing

Perhaps a little heat tape for the winter

 

[larry4406]

Rather than build raised false floor and worry about freeze, just cut the slab and put your groundworks in like normal. It’s done quite often either due to mistake or during remodeling.

Going up stairs to enter the bathroom due to raised floor means the door needs to inswing into the bathroom. If no stairs, door swing your choice.

 

[jetnow1]

A properly pitched drain should not contain anything to freeze, though I concur with larry4406.

 

[bad_idea]

Upon further research, I am thinking a urinal would be easier to install. Should be able to route a 1 1/2" drain line through the bottom plate into the cinder block and punch a hole out the block to the tank. The garage is only 10' from the house if I need a toilet. The problem is I have a bladder the size of a walnut. A sink would be great too.

 

[CraigStu]

Build the room, install one of these
https://www.westmarine.com/buy/thetford--porta-potti-135-portable-marine-head--17959826?recordNum=1
and no plumbing needed.

 

[larry4406]

Go big and put in a sink, a toilet, and a shower.

I had that at my last garage (plus a urinal) and it was awesome to clean up out there and bring only dirty clothes to the house. Wife liked that concept as well. Hardest part was to remember to bring clean clothes out prior to starting work.

 

[sberry]

I could do without the shower but the sink, stool and the pisser are good and can use it for guest types on occasion too. I would cut the floor up. I have seen the build ups too, all look,,, well,,, like an afterthought at best.