Tee into soil stack.

[dave5576]

Hi all,

I'm building in cloakroom in my utility room. There is an existing soil stack I want to tee into. There is an existing washing machine waste feeding into the pipe which I need to keep. I want to tee in from the opposite side.
All the black and grey tee fittings appear to have a fixed boss either side which will not suit my scenario as I need the 40mm boss on the opposite side to the new toilet inlet. Can I use a solvent weld boss on one of these fittings, is there space between the fixed bosses? Or, if not can I use an orange /brown underground tee, will I be able to solvent weld to it?
Many thanks in anticipation.

 

[CountryFan]

Washing machine waste looks like it’s running uphill slightly anyway. Can you use a short boss connection and then a branch?

 

[Hugh Jaleak]

Bear in mind, regs do not allow an opposed connection within 200mm of the centreline of the WC branch connection. I'd see where the top of the junction is going to sit, and see if it's viable to fit a strap boss immediately above that for the washing machine waste.

 

[dave5576]

Thanks Hugh, I presume that's why tee's aren't available with a boss opposite the WC connection. Do you know the minimum height from the washing machine outlet to a boss?

 

[Hugh Jaleak]

Actually commented on another post yesterday, where the sink boss was opposite the WC branch, so there are/were such fittings available, but might take some searching. https://www.diynot.com/diy/threads/waste-plumbing-potential-problem-with-branch.641603/#post-5915821 it may be worth asking the OP on that post if they can ID the Manufacturer of that particular Junction.

Height of Standpipe, basically I don't think there is any regulation, but ideally as high as possible, given the constraints you are working to.

 

[dave5576]

Many thanks for your comments, got it done, ready for WC and basin. The slip coupling was a pig to slide over the pipe.

 

[Hugh Jaleak]

The slip coupling was a pig to slide over the pipe.

Did you use a suitable lubricant?

The Boss Adaptor doesn't look to be fully 'home' in the socket, I'd try and get it right the way in, you don't want to risk it leaking, especially when the stack is boxed in again.

 

[dave5576]

Thanks, the rubber insert is longer than the boss, it might go further in if I enlarge the hole but concerned about it making an intrusion in the stack. I used silicon spray but I think washing up liquid would have been better.

 

[dave5576]

Next problem is the height of the inlet into the stack, it's 200mm above finished floor level, every pan I've seen has an outlet at 180mm. I could raise the floor but don't really want to. I'm placing the toilet cabinet next to the riser so it will only be 250mm from centre of the pan outlet to the inlet to the stack.

 

[Justin Passing]

Touch n go at 20mm uphill. Maybe add a sheet of ply in the cloakroom? I HAVE put loos on plinths of ply, jig sawn round to match the angle, and painted white.. You don't notice after a bit.

 

[Justin Passing]

T'was back in the days when I cared. It was only a renter. On one I filled all the ply end-grain with car body filler so coud get it smooth. It was 3 layers of WBP 19mm, with an overall tilt because the floor was sagging so much.

 

[Hugh Jaleak]

What's the drain made of, plastic or clayware? Looking at it, I reckon you may be able to lose a few mm, enough to get you where you need to be with the Pan. Better to deal with it now, just getting an inch lower would probably be enough to scrape through, ideally slightly more.

If it is clay, offer up a McAlpine DC-1, drain connector, this will probably fit inside the clay collar, lowering the height of the junction. If it's plastic, you may be able to trim it to a suitable height, and using a 110mm coupling, lower the branch to the right height for the pan position.

Either way, it looks suspiciously like a pan connector has been used to make the joint between the stack and the drain, not ideal....

 

[dave5576]

Thanks for your response, it's a clay pipe with an adaptor of sorts, it's soft and pliable, I'm no expert but haven't seen anything like it before, your comment about it may be a pain connector is interesting. Do you know the usual way of connecting plastic to clay?

 

[Justin Passing]

Here's some options!

 

[blup]

A flexible clay to plastic adapter may be your best bet. Although used underground yours would be boxed in. You just need to find the extra space to nibble off the clay waste