ABS/PVC glue-up. Rules of thumb?

Hi all,

I've designed and fitted one leg of my new DWV for the toilet and shower. Thanks to advice from the forum I'm confident of the sizing and layout. I'm now preparing to cement things together and wonder if there's an order to gluing-up that you more exeprienced people have arrived at that. A "typical" approach?

I know that every situation is different, and so, strictly speaking, "there are no rules of thumb." But -- when you approach the gluing-up stage of a new DWV installation is there a certain order that you tend to do things in unless/until something unusual arises?

For instance, do you tend to build from the lowest level, say the main waste line, and build upward as much as possible? Or build the trickier sections first and then finish by cementing in the longer runs of pipe?

I know I'll get the thing cemented and it will be fine, but I bet I'll do some chunks of it the hard way, or a harder way, than if I had already fit and cemented miles of the stuff in my career.

So? Help, Mr. Wizard!

Thanks,
Charles

cementing

You start at the beginning of the run, wherever it makes its initial connection and then proceed upstream from there. If you do a section and then work to it, you may wind up with no easy way to get it connected.

I always hang the fitting at the furthest fixture first. It's center line establishes grade for the rest of the run.

And just to be ornery, I will say that sometimes, if I know that I will be going through a joist, I determine where the hole will be first, and then plan from there.

When a joist is drilled, you need 2" or more at the top, and the bottom.

When you are installing a shower p-trap, you need to know how deep it will be, or it will be bump the drywall.

If you are connecting to a closet flange, you will need to know the method.
Hub, spigot, tight or with some distance to work with.
That can also be a determining factor.

I will say, depending on circumstance, it can change.

I do like to put the trap arms and traps last if they are in the open,
But if drilled through studs, then I will put the horizontal first and then the fittings.

So for me, I cut and weave depending on the defenders, trying to make it as fast to the goal line as possible.

Awesome. Thanks. All of it makes sense and the picture is coming into focus.

One friend also advised, "have lots of 22-1/2 bends on hand for jiggling things." So far I've managed to get it done without them.

Charles

you mean you just dry fitted the plastic? your not gonna bottom out your fittings

Actually, I've seen that advice here before and had my antenna up. I measured the pipe lengths from the bottom of the sockets and can tolerate a little error in most of layout anyway.

For fun, I'll measure a dry-fitted join before and after cementing and see if there's an appreciable discrepancy.

Charles

Hi all,

Quick follow up on he dry fitting thing. It works. A super-PITA with the 3" an 4" stuff, but it measures the same before and after cementing.

I'm cutting with a chop saw so the ends are square, and wetting to help insertion (no comments please) and of course drying and cleaning before cementing.

It's not generally recommended, or rather, it's universally not recommended, but I needed the visual.

Thanks for the help,

Charles

charles, the only other thing i can offer, as a DIY'er that's not fond of plumbing at all LOL, is that if you dry fit stuff, and get it all built, and bottomed out the fittings, mark them all with a sharpie or something so you can easily duplicate the orientation. (this has worked for me in the past)

YMMV.. hope this helps
mike

Thanks Mike,

Yep, I have been burned by neglecting that. BTW a silver sharpie *rocks* when using black ABS.

Charles