# Forum Home Renovation Roofing  How to cut downpipe to make it a slip joint back over itself

## DaleBlack

Hi most of my downpipes are cut like the below, when the clamp is in the cut is hidden   
its handy to loosen the clamp and wriggle the cut piece of downpipe up to service the grill etc 
below i have made a cut at the clamp spot , cutting away about 500mm   
however i can not get it to slip over. I tried flipping it over, one end of the downpipe from Stratco, has a little symbol which i thought might indicate a larger end however whilst it does seem larger (a little) i cant seem to get it over either. 
what is the technique here?

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## gpkennedy

i would use a pair of tin snippers to cut some small V slivers out of the small sides of the top downpipe, pinch  the ends in a tad so that one fits over the other. You may have 
cut off the slightly flared end when you shortened the pipe, thus the new diameter of the two pipes are the same size.

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## Tools

You can buy a tool to crimp the pipe to make a small end, but for one pipe you probably won't. 
Tools

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## plum

You've cut the large end, you should of cut it from the bottom [ the small end ]. Best bet, unless you want it to look dodgy is to buy a new piece of 4x2 c/b downpipe and cut it properly.

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## RodEye

> Hi most of my downpipes are cut like the below, when the clamp is in the cut is hidden   
> its handy to loosen the clamp and wriggle the cut piece of downpipe up to service the grill etc 
> below i have made a cut at the clamp spot , cutting away about 500mm   
> however i can not get it to slip over. I tried flipping it over, one end of the downpipe from Stratco, has a little symbol which i thought might indicate a larger end however whilst it does seem larger (a little) i cant seem to get it over either. 
> what is the technique here?

   What were you thinking? "That trick never works, Bullwinkle". Of course, the downpipe on either side of your cut was always going to be the same size. There is no magical way of shrinking or expanding either end of your cuts to get the desire you are after, of being able to slide the lower end of the downpipe up with ease.You can do what gpkennedy suggested and the clamp/clip may hide the butchery.  Downpipes generally come in two different lengths, 1.8 & 2.4m. In some cases the big end will slide over the little end upto 0.5m.  If you can't see a join in the downpipe further up, then it is either hidden under the upper clip or the downpipe is of one continuous length.

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## DaleBlack

It was installed as one continuous length by a carpenter a few days before as part of a skillion roof he put in. Yes it was never going to slide on how I wanted, silly of me to have tried, however I still needed to make the cut to achieve what I wanted. (I didnt discuss this discrete need with him, my fault) 
Solved, by buying another one, $27, cutting approx 500mm from the big end, then sliding that over. Now the whole 500mm slides smoothly up and as you can see below the cut is hidden by the bracket.
It will be met by a rectangular to round 90mm stormwater adaptor and further pipework to carry the water away to a soak well rather than undermine that wall. But it wont be hard plumbed and I can slide this cut piece up if needed to try to service it. Ill put mesh up in the gutter to stop leaves.     

> i would use a pair of tin snippers to cut some small V slivers out of  the small sides of the top downpipe, pinch  the ends in a tad so that  one fits over the other.

  I assume this fix would have simply enabled me to put it back on and slide it over 20mm or something? not the 500mm it slides right now? 
cheers

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