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Cementing 1/2 inch CPVC in crawlspace

2466 Views 6 Replies 5 Participants Last post by  steve3847
Cementing 1/2 inch CPVC in crawl space

I went into crawl space yesterday and cut 1/2 CPVC pipe with a ractchet pipe cutter. That worked out much better than a hack saw. I had turned the water off at the road but water still dripped from where I had cut the pipe. I wanted to use primer and cement but water would not stop dripping out of the pipe. I called Home Depot and the 2 guys in the plumbing department said I could use a sharkbite to cap the CPVC pipe and it would be ok. The guy at Home Depot didn't come out and said it but he indicated to me that just because the main water valve is off does not mean a small amount of water won't keep dripping from the water pipes. I don't know if that is the reason the water kept dripping but it did not stop so instead of laying in crawl space a few more hours I capped the 1/2 inch CPVC pipe with a sharkbite and that worked out ok. I was told not to put primer and cement on the 1/2 inch CPVC pipe if water continued to drip from pipe.

My plumber installed a new kitchen and bathroom faucet and he was able to do this without any problems far as I know. However, me being in the crawl space where the water pipes run parallel to the ground I could not get the pipes to stop dripping even after 2 hours. The turn off value is actually at the road which is about 3 feet below the house. Considering the turn off valve is 3 feet below the crawl space floor and water pipes are about 24 inches above the crawl space floor that is 5 feet total difference in height from turn off valve to the pipe that was dripping. Can't figure out why water would continue to keep dripping. The plumber at Home Depot said their is a tablet that you can insert into the pipe and it will stop the flow of water while you are applying primer and cement. Then it dissolves away later. Is that what I needed. Is there any tricks to doing this or do you have to wait over several hours before the excess water in the pipe will stop dripping ?????

I am going to do the same with the hot water pipe in a few days. I'm hoping that the water in the water heater won't drain out. That would be several gallons of water coming out of the water heater. Just to cap a 1/2 inch CPVC pipe. Anyone can answer that ?????

I would like to be able to do stuff like this on my own without being charged an expensive bill from a plumber. I googled about the tablets but came up empty.

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Bread is an old trick, however use Wonder Bread, which will dissolve nicely after you turn the water back on. High quality wheat and rye bread dissolve poorly. An alternative is to purchase a freeze plug device, this is a magnetic cooling unit that clamps around the pipe, you apply current and after a few minutes the water freezes. Works very nicely, but costs a lot more than a loaf of Wonder Bread. By the way, Hostess is out of business, so you may have a difficult time finding Wonder Bread, so the option is the cheapest white bread made. Just curious, why is this an issue, you used a shark bite?

The water likely kept dripping because gate type valves, often used as shut offs, are almost never leak tight. Sometimes terrible things go wrong, like the valve fails in the closed position, creating all kinds of issues. Much better are the quarter turn ball valves, more reliable, better seal, last longer. Also cost more.
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