# Forum Home Renovation Plumbing  Joining into existing 90mm PVC pipe

## Theremin

I have an existing 90 mm stormwater pipe running in the ground beside a rainwater tank that has just been delivered.  I want to run the overflow from the tank into the existing pipe.  What is the best way to do this?  The existing pipe runs for quite a few metres in either direction from where the new pipe will join in, so digging it up will be quite a job.  Is there a special fitting you can buy for this type of situation?

----------


## munruben

Seems a pity to waste the overflow water into the storm water drain, can't you direct it to somewhere more useful such as swimming pool top up if you have a pool or on the garden? If you can't or dont see the need to do this, then you can buy a T or Y junction joint from Bunnings to do the job.

----------


## journeyman Mick

90mm is pretty thin wall and therefore flexible. If you dig up about a metre either side you should be able to get enough flex in the pipe that you can cut it, lift it up and then  spring a t-piece on (with primer and glue of course) 
Mick

----------


## pawnhead

If you don't want to bother digging a hole big enough to spring in the tee, then Iplex makes a repair coupling (scroll down). Basically, a joiner that comes in two pieces, with a locking strip for each side. You'd just have to dig enough to fit the tee and the coupling then.

----------


## journeyman Mick

> If you don't want to bother digging a hole big enough to spring in the tee, then Iplex makes a repair coupling (scroll down). Basically, a joiner that comes in two pieces, with a locking strip for each side. You'd just have to dig enough to fit the tee and the coupling then.

  Didn'trealise they made them in 90mm, only ever seen the 100mm ones. Good to know, although up here you'd probably have to wait more than a week to get one. :Rolleyes:   
Mick

----------


## Theremin

The repair coupling is what I'm after, although surely I don't have to order one in from NZ!?  I wonder if Bunnings stocks them...?  

```
 
Seems a pity to waste the overflow water into the storm water drain, can't you direct it to somewhere more useful
```

 Don't quote me on this, but I think the local regulations require it to be plumbed into the stormwater.  I have to send photos of the tank to claim the Govt rebate and don't want to give them a reason to knock it back.  Although the stormwater pipe just runs out into the garden at of the back yeard anyway so it won't be wasted  :Biggrin:

----------


## pawnhead

> The repair coupling is what I'm after, although surely I don't have to order one in from NZ!?  I wonder if Bunnings stocks them...?

  They could probably get one in. A decent plumbers supply shop would stock them I'd imagine.

----------


## SilentButDeadly

Iplex are in Australia too.....  http://www.iplex.com.au/search/ProdD...1381200349&cat=

----------


## wonderplumb

Mate better than a repair coupling, which incidently only come in 100mm, you can but 90mm slip sockets, so the socket fits over the pipe and can freely slide along the lenght of the pipe. You only need to dig up enough to cut in a tee or junction, aswell as enough for the slip socket and your done.

----------


## wonderplumb

> 90mm is pretty thin wall and therefore flexible. If you dig up about a metre either side you should be able to get enough flex in the pipe that you can cut it, lift it up and then spring a t-piece on (with primer and glue of course) 
> Mick

  Pretty thin but as brittle as buggery, it will snap as soon as look at it, a handy hint is to cut it with a hacksaw, as a woodsaw will just rip chunks off it, 90mm is a prick of a stuff, thats why I always use 100mm DWV, gives a better job allround.

----------


## journeyman Mick

> Mate better than a repair coupling, which incidently only come in 100mm...............

  If you follow Pawnhead's link to the Iplex website you'll see thay do come in 90mm. I thought they only came in 100mm also. 
Mick

----------


## wonderplumb

> If you follow Pawnhead's link to the Iplex website you'll see thay do come in 90mm. I thought they only came in 100mm also. 
> Mick

  ????? hey so they do, I wonder how readily available they would be from your local plumbers supplies........... might suss that out.

----------


## Theremin

Well, after all that, Bunnings sell this 90mm coupling that doesn't have a ridge down the middle like the other ones I have seen.  So, it simply slipped over the pipe, I joined everything up leaving a gap, then put some glue on and slipped it back to join up the gap.  Easy.  Here's a few pics of what it's all about.  The only catch is, this little piece of plastic was $5.50!!!  :Eek:

----------


## Naf

I need to do similar to this, as this thread is a couple of years old is this the easiest/cheapest way of doing it still or is there new and wonderful products to achieve this. 
Thanks
Nathan

----------


## Naf

Anybody?

----------


## cherub65

Slip joint it is  :2thumbsup:

----------


## Naf

Thanks Cherub 
And the portfolio section on your website is incredible, some amazing work there. 
Nathan

----------


## Gracehoper

I have used the method described here to insert 90mm pipe into existing length, and it has worked fine. But *today I tried this and it failed* and so I need advice. 
I usually use a single coupling cut into two 55mm sections. I slip one half of the coupling to each of the outer pipes in the ground and slide back so the ends are visible about 30mm. Then cut a piece for the gap. Then prime and apply glue to one end in the ground and one end of the insertion piece, and quickly slide the coupling over both ends and hold till firm. Then repeat for the other side. (I can't see how to apply glue on the inside of the coupling so I leave it out.) 
Today when I slide the coupling over the two glued ends *it pushed almost all the glue off one end onto the other side* and then set pretty quickly as it usually does. Consequently it did not stick the two ends together. 
Does anyone have any ideas about what could have gone wrong? 
It's pretty new glue, use by 2011. But I am near the end of the tub and it was looking slightly lumpy, just a bit, though it spread okay it seemed a bit thicker than usual. I'm *wondering if the coupling is slightly flared* internally at each end to prevent this problem, and when cutting it in half I should ensure the flared end is closest to the glue, so it rides over it... 
Having another go today.

----------

