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How do I fix drainage

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How do I fix drainage

I have this drainage in my backyard and it seems to be broken or maybe it wasn't installed properly when concrete was done not sure!

Looking for some advice on a diy fix, I was thinking of breaking the concrete around the sides and installing new drainage and doing the concrete on the side again?






Upon inspection, I can see the drainage is of this DT mound type, so looks like I might have to break more concrete, 


image from internet that resembles my current drainage


I do want to keep the drainage since there is a tap just above it so am also looking for any options for new drainage to avoid this issue. 

Thanks, heaps.

Bunnings Team Member
Bunnings Team Member

Re: How do I fix drainage

Welcome to the Bunnings Workshop community @jp171. It's fantastic to have you join us, and many thanks for your question.


It's a bit hard to tell why that pipe isn't connected, but there doesn't appear to be any glue on the joint area. As you have suggested, you'll need to chip the concrete back around the fitting by a few centimetres and remove it. The pipe also appears not to be long enough to connect securely, so you'll likely have to add a short section onto it. This might cause issues because it is actually quite hard to add a short length of pipe. You'll need a connector and a new piece of pipe which will be longer than the space you have to work in. I presume this could be the reason why it wasn't connected in the first place. The pipe was too short, and it was easier to leave it disconnected than trying to extend it. Instead of lengthening the pipe, lowering the grate to a height where it fits the pipe correctly would be a solution. You can then repair around the grate with mortar and taper the edges to accommodate the drop in grate height.


This might not be a professional approach, but if you clean the pipe thoroughly, you could join the pipe to the fitting on the inside with T-Rex 48mm x 1.5m Strong Waterproofing Tape. I'm not sure how long that will last with water constantly trying to pull up the edges of the tape, but the aggressive butyl adhesive on the tape is pretty impressive stuff.


Please let me know if you have any questions.




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Trusted Contributor

Re: How do I fix drainage

Hello @jp171 


Welcome to Bunnings Workshop. In these situations perhaps you can try using a Holman 100mm PVC DWV Slab Adapter / This is used to extend drain pipes that's either too close to the slab or is in need of an extension. The slab adapter is tapered to fit in to 100 mm pipes but with a top end that is the same width as a 100 mm pipe. This is assuming you have a 100 mm pipe drain pipe in the picture. The slab adapter can be cut down to size so that it does not protrude above the waste gate. Once you've tested it and have found the correct level simply cut and glue in place. You may ask the plumbing specialist in the store by showing them the picture you've just posted and I know they will understand why I suggested this in this particular situation. I hope my suggestion helps and please don't hesitate to post any other questions. Good luck and stay safe.





Screenshot_2021-04-18 Holman 100mm PVC DWV Slab Adaptor.png

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