Day 152: There's a hole in our basement!

Don't worry, we asked for it to be dug there.

After the revolving door of plumbers (7 in total!) were in to give us quotes on the job of roughing-in the drain-waste-vent system for the basement bathroom, we gave our chosen plumber (a father and son team) the go ahead. They were in yesterday morning doing all kinds of jackhammering and digging.

What you see in the photo above is a line following the main drain from stack in the far right corner (hidden behind the softener tank and a coat of spray foam, to the left of the window). This may make more sense once I show you the layout of the fixtures that we've evolved to.

As discussed on Day 145, space along that back wall is way too tight to fit three fixtures. Given the size of the room, we're comfortable with a single sink set in the counter on the interior (left) wall. [Whether that sink is utility sized or a regular vanity is another unresolved debate that arose when we got to stand in front of the quite large utility sink instead of staring at it mounted on the wall at 15 feet. And the exact form of the counter and cabinets is also in the air. We're not too concerned about it at this very instance since we're planning on building them to fit the space. Unlike the shower, which we did need to decide on so that the plumber could properly position the drain.] The point of this picture is that we need four drains in the bathroom (sink, toilet, shower, washing machine). We're also putting in a floor drain in the utility room with a line for the cistern overflow, water softener discharge, and furnace condensate pump. This is why there is a big hole in our basement. Luckily, all this plumbing work is happening directly over the main waste drain running through the basement so it seems like it won't be too hard to tie in all the drain lines.

From my small exposure to plumbing, it seems like the most complicated part of it all is the "vent" part of the "drain-waste-vent" (or DWV) system. As a newbie, I didn't know all the details about how drain lines need to vented with 5 feet to allow sewer gasses to escape through the roof and to let air through so that water can drain easily. (I've told myself it's like that gap of air you allow when pouring juice. If you don't leave a little gap at the top of your bottle opening, the liquid sputters and jerks out instead coming out with a nice pour. Whether this is actually the same function that vent pipes perform, you'll need to ask the more technically inclined - aka Garrett.) The problem here is that this bathroom is being built in the basement, two stories below the roof with lots of finished plaster and living space in between. To put in a full vent would require lots of work on the main and upper stories in the house, including opening walls and possibly tearing out closets. Understanding this is not an ideal or, in some cases, an economically feasible situation, the air admittance valve (AAV) comes to our rescue. Also known as a "cheater vent," the AAV allows air to flow into the drain pipe but keeps gasses from exiting with the magic of a spring. You can find a nice a clear diagram here. In the past, these devices were only legally allowed in mobile homes but a higher quality version has been developed and is CSA (Canadian Standards Association) approved for use in houses. While it's not the absolute best solution, it's the most logical approach for us at the moment. So, with the go-ahead from our friendly neighbourhood building inspector, the plan is to put in an AAV in the utility room wall to vent the bathroom drains. When we get around to doing the kitchen and upstairs bath, a full and proper venting system will be built at that point and we can tie the downstairs bathroom into that system.

So our plumber is back tomorrow to do the actual work of putting in the drains and vents. We did a bit of work these past two evenings to prepare space for pipes to get slotted into the exterior wall (instead of on the wall with strapping, as the plumber had suggested, which would have narrowed the room by a precious 2-3 inches).

I should mention quickly that the kitchen drain is our attempt to think/plan ahead. Currently, the kitchen drain cuts through a number of cabinets above the main floor before tying into the main stack. This will be a pain/restriction when we get to rearranging the kitchen. We've asked our plumber to prepare the kitchen drain pipe to allow us to bring the drain below the floor right under the sink. This drain pipe will come up under the sink and, right now, wait patiently until we're ready to hook up the sink with a vent. Doing the bottom part of the drain now will (hopefully) save us a big headache in the future, especially since that wall will be closed off with a shower built directly in front of it.

In an ideal world, all of these pipes would have been threaded through the studs before we did the spray foam. But in a world of ecoENERGY deadlines and not wanting to rush on the bathroom layout, we had to resort to carving out spaces in the spray foam and through the studs for the pipes. If this framed wall were a supporting wall, putting such big notches in studs like this is probably not advised or is at least done with caution. But since this framing is really just a place to hold spray foam and attach drywall, we were pretty comfortable notching out the studs. With over 5 inches of spray foam, that wall isn't going anywhere. We had fun cutting out the spray foam: I carved out little grids with a utility knife and Garrett dug them out with a putty knife. The studs were a much easier and quicker affair:

Thank you drill + hole saw.

From the perspective of a farsighted laundry drain pipe.

Our plumber left us a piece of the drain pipe to test in our notches and it fits very nicely. I'm planning to pick up some metal protector plates to put on the front of the stud over the notch in case we accidentally try to screw some drywall into the drain pipe.

I'll end here with some birthday art Garrett made for me from the notched out wood:

Totem pole + wolf on a boulder howling at the moon.