I am getting the waste stacks ready for inspection on a new build 4 story apt complex with about 100 units. I am only testing one side with about 28 apts at this time and I have the stacks separated with Y's and weenies in the basement, but unfortunately there is no way to separate the floors. There is so much pressure by the time I get the water near the roof I end up blowing apart pipes at the cupplers on the 4 inch lines in the basement. Any tips would be greatly appreciated.

"Any tips would be greatly appreciated."
You only have a mid-raise to test for inspection. Here we put up high raises out on the Gulf beaches. We install inspection tees in the stackvents on each floor and put a inflatable test ball in the upper most tee, fill the stacks and call for a single floor inspection. When the top floor passes we deflate the test ball and let the water drain down to the next floor where we have another test ball installed and so on. You can do this with a couple of floors if you wish and call a inspection on two floors. But this method gets you out from under all that head pressure at the base of the stacks. Good luck, Tom

Good advice speedball. Did you use the test plugs that screwed in with the inflatable on the actual plug?

"Any tips would be greatly appreciated."
You only have a mid-raise to test for inspection. Here we put up high raises out on the Gulf beaches. We install inspection tees in the stackvents on each floor and put a inflatable test ball in the upper most tee, fill the stacks and call for a single floor inspection. When the top floor passes we deflate the test ball and let the water drain down to the next floor where we have another test ball installed and so on. You can do this with a couple of floors if you wish and call a inspection on two floors. But this method gets you out from under all that head pressure at the base of the stacks. Good luck, Tom

Good advice.

Back in the day when I still did multi-story buildings, rather than testing the entire system at once, we always isolated one unit from the other with drain cocks at the lowest points.

Aside from eliminating the blow-outs from too much head pressure as described by the OP, this also eliminated the need to drain the entire building down when leaks were discovered in the drain, waste and vent systems.

good advice speedball. did you use the test plugs that screwed in with the inflatable on the actual plug?

Those test plugs (http://www.cherneind.com/products-display.asp?pind=pp_3) are a great innovation.

We always end up installing a few sacrificial C/O Tee's on remodels to isolate the new from the old for testing and inspection purposes.

good advice speedball. did you use the test plugs that screwed in with the inflatable on the actual plug?

We didn't have those, Just inflatable test balls and mechanical test plugs.

Growler, What neat test plugs. We didn't have them when I worked out in the field.
The old test plugs used to get us soaked when we pulled them out to drain the stack.
Regards, Tom

The old test plugs used to get us soaked when we pulled them out to drain the stack.
Regards, Tom

Yeah, what a great initiation ritual for the newly hired apprentices.:D

My first dousing was after the water had stagnated in the system for a few weeks.

I got my Journeyman Plumber back, though -- I was standing on the roof of his van with the drivers side door open when I let the air out.:eek:

That's a stink you can never get out of the upholstery.:D