# Best way to cut pvc drain?



## vinny186 (Oct 8, 2016)

I cut out part of the subfloor in the bathroom because it had rotted but in order to get the new piece of plywood in I'll have to remove the flange. I was hoping I could cut away the vertical part but getting a tool in there will be difficult so I'll probably have to cut away the horizontal pipe. Any tips or suggestions?


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## vinny186 (Oct 8, 2016)

The air duct line has been fixed.


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## slownsteady (Oct 8, 2016)

You may be able to remove the metal duct at the elbow, and it may be easier than cutting the pvc back too far. You can cut the PVC with the sawzall or with an angle grinder as long as you keep the cut square. Cutting it back on the horizontal wouldn't be a crime, though, if it is the most accessible spot.


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## Snoonyb (Oct 8, 2016)

Actually, you do not need to cut the pipe at all. 1st cut and place two pieces of 2X backing tight to the bottom of the floor sheating edge, leaving at least 1" exposed into the void, next, Cut the plywood to be installed in two pieces; The first to fit from the joist on the right to the middle of the middle joist, cutting a "U" from left to right to just fit around the pipe. The 2nd half of the plywood installs from the middle of the middle joist to the middle of the left joist or in your case you install a 2X cleat to the side of the left joist for nailing.


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## slownsteady (Oct 8, 2016)

Makes sense. Just make sure the height of your finished floor will accounted for.


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## vinny186 (Oct 8, 2016)

I like the idea of not having to cut the pvc or duct but is there some standard (Holmes, perhaps lol) that says the floor will be stronger if I have one continuous piece of plywood instead of two?


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## Snoonyb (Oct 8, 2016)

The more blocking you can successfully place will further stabilize the floor, use 2" coarse thread screws to attach the blocking thru the existing floor sheating. Also the grain of the plywood the repair is cut from, IE., plywood will bend more easily across the 4' width, then the 8' length.


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## nealtw (Oct 8, 2016)

Cut the horizontal and remove it cut the other one too, install the horizontal with a joiner, add the joiner to the upright so it's ready for the flange.


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## frodo (Oct 9, 2016)

add some backing where needed,  cut plywood to fit hole

drill the plywood to fit the pipe not flange.  then cut the plywood in two pieces 

slide the plywood under the flange  on each side, secure wirth brass screws


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## johnjh2o (Oct 9, 2016)

Use a inside cutter.
http://www.homedepot.com/p/HDX-Inte...ter-67516/204277491?keyword=pvc+inside+cutter


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## Mastercarpenty (Oct 9, 2016)

An FYI-DIY plastic pipe cutting tip:

If you have access, a carpenter's or masons string will make a very nice pipe cut. Loop it around the pipe like a "U", then pull the ends of the string back and forth vigorously. It actually melts the pipe from the heat of the friction which is why ordinary string won't work but it can get you a clean cut in places where other methods won't work. Or it can save you a trip back to the truck for a cutting tool. 

I know it sounds crazy but try it and see for yourself- it really does a good job 

Phil


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## vinny186 (Oct 10, 2016)

Thanks for all the suggestions, I think they all would have worked but I went with splitting the plywood in two and wrapping it around the drain. When I get a chance I'll take a pic.


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## frodo (Oct 11, 2016)

Mastercarpenty said:


> An FYI-DIY plastic pipe cutting tip:
> 
> If you have access, a carpenter's or masons string will make a very nice pipe cut. Loop it around the pipe like a "U", then pull the ends of the string back and forth vigorously. It actually melts the pipe from the heat of the friction which is why ordinary string won't work but it can get you a clean cut in places where other methods won't work. Or it can save you a trip back to the truck for a cutting tool.
> 
> ...




string/copper jig


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## bud16415 (Oct 11, 2016)

[ame]https://www.youtube.com/watch?v=Dp8PSWHpSD8[/ame]


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## nealtw (Oct 11, 2016)

Bud: that's a great trick, until you think of the OP on his hands and knees face against the flange while he works.


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## bud16415 (Oct 11, 2016)

nealtw said:


> Bud: that's a great trick, until you think of the OP on his hands and knees face against the flange while he works.



Not my trick and Frodo worked  out the details on how to cut around corners with his jig made from copper tubing.


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## vinny186 (Oct 11, 2016)

This is what I have so far:
Yeah, my face wasn't getting anywhere near that flange lol - The pipe is too far away for the string method.
Installing two pieces of plywood around the flange didn't work because I couldn't get any support at the point just above the duct work so I ended up cutting out the flange with the inside pvc cutter (worked great btw, thanks for the tip). This never ending project could have been over except I forgot to measure the drain diameter and guessed 4" while at HD but of course it is 3." More to come...


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## nealtw (Oct 11, 2016)

That last spot does not have blocking, even if you can slide a piece of plywood half under and glue and screw will make the plywood one when done.


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## frodo (Oct 12, 2016)

I ran into a 4'x2'  piece of duct in the ceiling of a university cafeteria.  that was in the way of the bend of a p trap.
SO,,  I submitted an RFI [request further info] [also called a wtf todo]

 to the mechanical engineer,  as to what he wanted me to do.

His answer

physically  persuade  the duct work to allow the ptrap and duct work to occupy the same space, in close proximity

wth?  did this guy just tell me to beat the damn duct till it fit ? lol  

I was on a ladder, scratching my head,  when i spotted  a 12'' stainless steel mixing bowl on the counter.

I cut a hole in the duct,  dropped the bowl in the hole,  screwed it down, sealed it.  and set the trap in the bowl

moral o story....bet the duct, make your wood fit...


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## frodo (Oct 12, 2016)

nealtw said:


> Bud: that's a great trick, until you think of the OP on his hands and knees face against the flange while he works.



not me,  i cut it using long strokes.  

i stand up each stroke is a good 36''  get a good burn on that string

pvc wire saw
http://www.thespaworks.com/sites/default/files/imagecache/product_full/079724.jpg


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