Soil Pipe Diameter - Boss Strap

[MisterBevis]

Hi all,

I really hope you can help me. We're fitting Ikea kitchen units so I'm trying to move all the plumbing down to plinth level, but I've hit a bit of a snag.

My *plan* was to attach a strap boss to the black plastic soil pipe (pictured) to take a 40mm dishwasher waste. The grey pipe above (with a boss already attached) is standard 110mm, but the black pipe is wider - something like 130mm to 135mm.

Untitled

• MisterBevis
• 11 May 2013
• 1

Is this a standard pipe size and do you know if anyone sells strap bosses that will attach to this diameter of pipe? I can't use the boss above as it's too high.

Thanks!

 

[Phill Peck]

U want one of these

https://www.google.co.uk/search?q=b...AQ&biw=1024&bih=672#biv=i|4;d|S0GpPM10rLqCsM:

Is that black definitely plastic?

 

[MisterBevis]

U want one of these

https://www.google.co.uk/search?q=b...AQ&biw=1024&bih=672#biv=i|4;d|S0GpPM10rLqCsM:

Is that black definitely plastic?

Thanks!

So can I just solvent weld that straight into the pipe???
The black pipe feels warm to the touch and sounds plasticy when I tap it... I guess the only other possibility is cast iron?

 

[Phill Peck]

Gap filler is best for a boss it's like solvent cement but a bit thicker

Make sure the surface of the old pipe is thoroughly cleaned

 

[Phill Peck]

If it is cast iron you'll soon find out when u try to drill it

 

[Blagard]

If it is cast iron you'll soon find out when u try to drill it

LOL I was looking at the picture and thinking just that!

He should give the black pipe a gentle knock with a hammer - It will have a ring albeit a dull one if it's cast iron. I don't recall there ever being PVC pipe variations of that sort, and the size does seem about right for 4" Cast Iron Also the surface of the pipe will not be really perfect like PCV, smooth, yes, but with minor undulations in the glaze.

Edit: Oops just read the bit where he said he tapped it! - I stiil don't think its PVC though, now I am thinking of alternate pipe materials! Maybe pitch fibre, but that collar is not expected. Often CI will have the pipe size in embossed letters on the collar, so have a close look.

Last time - promise. Just below the grey PVC pipe and boss you can see the PVC collar that is typical of a PVC to 4" drain adapter possible cemented into a large collar. I still don't think the black bit will be PVC, but the OP thows me when saying it is warm to touch and CI is usually cold to touch.

 

[Blagard]

To get a lower connection, you could just tidy it all up and cut the pipe at virtually ground level and fit a multikwick adapter or one of the many alternative 4" to PVC adapters on the market, then put a proper boss pipe into it and connect to the PVC above with a PVC slip coupler. Getting rid of the old higher boss connection in the process.

 

[MisterBevis]

If it is cast iron you'll soon find out when u try to drill it

LOL I was looking at the picture and thinking just that!

He should give the black pipe a gentle knock with a hammer - It will have a ring albeit a dull one if it's cast iron. I don't recall there ever being PVC pipe variations of that sort, and the size does seem about right for 4" Cast Iron Also the surface of the pipe will not be really perfect like PCV, smooth, yes, but with minor undulations in the glaze.

Edit: Oops just read the bit where he said he tapped it! - I stiil don't think its PVC though, now I am thinking of alternate pipe materials! Maybe pitch fibre, but that collar is not expected. Often CI will have the pipe size in embossed letters on the collar, so have a close look.

Right, I've cleaned it up a bit with a cloth.

The collar definitely seems to be smooth plastic. I couldn't see anything embossed onto it. The black pipe below it, though, seems to have a bit of an uneven finish and is slightly crazed in a couple of places. It doesn't look like plastic, maybe more of a resin-like material. I tapped it gently with a hammer and there was just a dull thud.

So I'm guessing it's pitch fibre. I remember the neighbours saying they'd had some problems with drains collapsing a few years ago so I guess that it's probably been used in these houses.

Looks like it's back to the drawing board, then... Do you reckon something like this http://www.toolstation.com/shop/Plu...e+Boss+Connector+1+12+Black/d20/sd2907/p19672 would be any good for this, or is pitch fibre something I have to avoid drilling into at all costs? Time to go back to the drawing board, maybe?

Cheers!

 

[MisterBevis]

To get a lower connection, you could just tidy it all up and cut the pipe at virtually ground level and fit a multikwick adapter or one of the many alternative 4" to PVC adapters on the market, then put a proper boss pipe into it and connect to the PVC above with a PVC slip coupler. Getting rid of the old higher boss connection in the process.

Sorry Blagard I missed your last message. Is this something I can do with pitch fibre or is it best left alone?

 

[Blagard]

I would expect the bore to be 4" and so cut at low level fit in one of these McAlpine drain connectors with a boss on it then PVC pipe above with slip coupler above.

View media item 61243
I am not up to speed on pitch fibre , but it seems it was discontinued due to blistering with hot water and subsequent collapse! - I did not read any more as it was most unvomfortable to learn!

 

[MisterBevis]

I would expect the bore to be 4" and so cut at low level fit in one of these McAlpine drain connectors with a boss on it then PVC pipe above with slip coupler above.

View media item 61243
I am not up to speed on pitch fibre , but it seems it was discontinued due to blistering with hot water and subsequent collapse! - I did not read any more as it was most unvomfortable to learn!

Thanks very much! You guys have made things much clearer.

Sorry, just one more question...

If I fit a new piece of PVC pipe in with a slip coupling at the top, how do I ensure that the slip coupling stays in place and doesn't slide down the pipe past the joint? Or should I use one of those rubber tubes with jubilee clips at either end, instead of a standard slip coupling?

 

[Hugh Jaleak]

Slip coupling should be a pretty tight fit on the pipe. (Use a suitable pipe lubricant and make sure you chamfer both ends of the cut pipe before attempting to fit it or you'll displace the seals!) If in doubt i'd put a jubilee clip round the pipe to hold it in place.

I would however be very cautious attempting to cut the pitch fibre, not seen much of it, but I believe it can be very fragile and may collapse soon as any pressure is applied.

 

[Phill Peck]

It won't slip they are tight

Mark the pipe though so you know it is in the middle

 

[Blagard]

While it is a slip coupler, it is not that slippy if you get my drift!

You could solvent a scrap of PVC to the outside of the lower PVC pipe to help alignment and to give you peace of mind!

 

[Phill Peck]

Cut the pitch fibre with a wood saw

Fine tooth one if u have it