Kitchen Sink waste has a uphill section (See Pic)

[Donboy1983]

Hello,

Im new to the forum and just after a bit of advice before my kitchen gets fitted. The waste pipe for my sink has to be back against the wall for the units to fit. the only way this was possible was to route the pipe work like this.

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• Donboy1983
• 10 Mar 2014
• 1

Will this cause a issue where the vertical part is next to the stack pipe? or will it be ok because it is still below the water line in the sink?

its only a 2mtr run and its all in 40mm pipe.

Hope someone can advise.

Thanks Don

 

[Charnwood]

Is it possible to turn the trap 180° to avoid what I've circled in red so the pipe follows the black line? Will that create a fall to the boss?

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• Charnwood
• 10 Mar 2014
• 1

To do it your original way really needs a new boss fitting lower on the soil stack.

 

[Blagard]

As Charnwood - Fit a P trap to the sink. On no account do it the way you have drawn. Fit a new connection lower down if you have to.

 

[NotAgainFFS]

I just fitted a strap on boss.

It wasn't hard to fit once I had the right parts and some kind people on here helped me every step of the way.

So if your stack is plastic that might be an option if you can't adjust the pipes as suggested and will get you a lower connection to the stack.

Something like this might work:

http://www.plumbcenter.co.uk/en/plu...-g-strap-on-boss-nut-and-blt-110mm-grey-56599

 

[Donboy1983]

I think I will just drill another hole and buy a strap on boss.

is this easy to do?

I'm guessing I will need to buy a 42mm hole saw to fit the 40mm pipe inside?

also do they just push fit or do they need to be bonded with solvent?

Thanks for the info.

 

[NotAgainFFS]

In my case the boss and the insert were separate parts and the chaps at plumbase helped me out with the right one. I used solvent weld but I believe that push-fit and compression versions are available too.

I used a hole saw and my cordless drill - mine was a 50mm version. Took about 5 minutes and I was on the top of a 7m ladder.

I'm no expert though so I'd take the advice of a pro before anything I say

 

[Blagard]

I think I will just drill another hole and buy a strap on boss.

is this easy to do?

I'm guessing I will need to buy a 42mm hole saw to fit the 40mm pipe inside?

also do they just push fit or do they need to be bonded with solvent?

Thanks for the info.

The strap on boss is initially a 50mm size and you use a solvent to weld it to the stack. Check the strap boss for actual hole saw size

Then you need the adapter to fit into the boss to suit the waste pipe size which in your case will be for a 40mm waste.

These would do it
http://www.wickes.co.uk/invt/431959
http://www.wickes.co.uk/invt/431951
http://www.wickes.co.uk/invt/431964

http://answers.wickes.co.uk/answers/9987-en_gb/product/431959/questions.htm
Wickes have not got a clue on the answers to using on a cast iron stack - You can't use a PVC strap on in that case! But you will be OK with PVC

 

[Donboy1983]

Thanks for that, I was just looking at that on the Wickes webpage. Is the solvent weld easy to do. I guess you just put it on and let it do its thing.

I also seen this in Screwfix that requires no solvent glue,

http://www.screwfix.com/p/mcalpine-mechanical-pipe-boss-connector-black-40mm/55722

 

[Blagard]

Thanks for that, I was just looking at that on the Wickes webpage. Is the solvent weld easy to do. I guess you just put it on and let it do its thing.

I also seen this in Screwfix that requires no solvent glue,

http://www.screwfix.com/p/mcalpine-mechanical-pipe-boss-connector-black-40mm/55722[/QUOTE]

A good idea, McAlpine make good products so I would use one as well!
Illustration in the link below - Make sure you use the correct size hole saw on that one

http://www.mcalpineplumbing.com/media/cat/33.pdf

 

[MJN]

Hi Donboy,

Have you considered an Hepvo waterless trap? It can connect straight to your sink and whilst your diagram obviously isn't to scale you may find it will be high enough to allow sufficient fall whilst still being able to enter the existing soil pipe connection.

Mathew

 

[Whitespirit66]

https://www.youtube.com/watch?v=UDLWHJPqviM

 

[MJN]

That particularly video is fine, and some good tips there, but it pays to be cautious with Tommy's guides - check this one out for fitting a water butt with diverter:

https://www.youtube.com/watch?v=U9QTeW7UAT8

(Skip to 2:05 for the clanger)

Perhaps by'Tommy's Trade Secrets' in this case it is how the diverter is expected to function properly and allow water to continue flowing down the downpipe once the butt is full. I wouldn't follow his advice to solvent weld the fittings together either!

 

[Whitespirit66]

Haven't seen that video - will have a look. Some of the videos are filming a real pro of a chippy, doing stuff like levelling floors, mitreing worktops, kitchen fitting, skirting installation.

Real quality stuff and some of the best on YT.