Dry Fitting 2" PVC Drain Line Problems

[RustyKnuckles]

So I'm plumbing the drain line from my new shower. I'm trying to dry fit the 2" PVC first, but I can't push the 2" PVC pipe all the way into the various fittings. I can only get them about 1/2 way in before they seize up. I'm not a plumber, but have done lots of building over the years. This is for my retirement home that I've built myself. The fittings are white PVC, from Charlotte Pipe & Foundry, made in the U.S. Any tips?

 

[wwhitney]

By design they are impossible to fully seat dry. It's an interference fit, and only with the primer and solvent cement softening the mating surfaces can you fully seat the pipe in the hub.

So if you want to dry fit, the easiest thing is to use twice as much pipe. Your dry fit pipe segments are intentionally short because they don't seat all the way. Then once you get all the fittings where you want them, you measure the distance between fitting hubs, add twice the hub depth, and that's your final pipe segment length. [Plus maybe do a couple test glue ups on scrap fittings of the same diameter, to see if you need to systematically add/substract 1/8" or 1/4" to the above computation, which could happen depending on small details of how you read the tape measure, how you make up the joint, how square you are able to make your pipe cuts, etc.]

Cheers, Wayne

 

[Sponsor]

 

[RustyKnuckles]

Thanks Wayne, I'm only dry fitting because the plumbing book I'm using, from Taunton Press, says to do it. I trust Taunton Press--they publish Fine Homebuilding, which I subscribed to in the 1980's and '90's. But I don't really HAVE to dry fit I guess. I have plenty of room down in my crawl space to move around, and to make the pipes go where I want them to. I'll try not dry fitting a few and see what happens. Thanks.

 

[Reach4]

One thing to consider is to make some prototype/measuring pieces. Put some cuts (kerfs) in the end, and push that into the tapered hole for size. After you get things the way you like, take out those pieces, and put in new pieces cut to size.

 

[Terry]

I don't really care what "FineBuilding" says, it's an interference fit that only goes together with solvent. Every plumber knows that. It's not something new.
But sure, if their book has a new idea about what we have been doing for decades, why not. Good luck with that.

I have also seen things in their magazine that are downright wrong, illegal and really, really bad ideas.
It's your house though. Do pull a permit and see what your inspector says though.

Page 85 has instructions
https://www.charlottepipe.com/Documents/PL_Tech_Man/Charlotte_Plastics_Tech_Manual.pdf

 

[RustyKnuckles]

Thanks Terry. I'm out in the boonies, where no building permits are required, except for the septic, which I passed on the first inspection, but my brother is a retired code enforcement officer, and has only objected to one thing about my build so far--he didn't like where my electrician put the breaker box. But we worked around that.

I have to agree on FineHomeBuilding--I've also seen things in it that I thought were wrong, but overall I still trust 'em. This was back in the late 1980's and '90's. But I haven't read them in 20 years.

I just read the labels on both the Oatey primer and Oatey glue. The label says to dry fit, but the pipe will only go into the fittings 1/3 of the way when dry, and to take that into account. That's exactly how far mine go in dry--1/3 of the way. So tomorrow I'll glue a few up and see how it goes.

 

[RustyKnuckles]

I just primed and glued two pieces, and it worked great.