Boss rubber adaptors for connecting waste pipes to boss bosses on soil stacks or pipe runs. Available in 32mm and 40mm to suit most standard waste fittings. Simple push-fit installation with no special tools needed.
Size
Price
QTY
32mm
£0.99£1.19
40mm
£0.99£1.19
A boss rubber adaptor is one of those small parts that sits quietly in a toolbox until the moment you absolutely need it, at which point it becomes the most important thing on the job. These rubber adaptors are used to connect 32mm or 40mm waste pipes directly into a drilled boss on a soil stack or pipe run, creating a watertight seal without the need for solvent weld or complex fittings. Simple, effective, and far quicker than the alternatives.
The rubber compresses into the drilled hole and grips the inner wall of the boss, while the waste pipe pushes through the centre of the adaptor to lock it in place. This creates a reliable seal that handles normal domestic waste flow without any issues. Both sizes cover the two most common waste pipe diameters used in UK plumbing, so between them you have most sink, basin, bath, and shower waste scenarios covered.
Where Boss Rubber Adaptors Get Used
These are used every day by plumbers connecting new appliances to existing soil stacks, particularly on retrofit jobs where cutting into existing pipework needs to be kept to a minimum. Drill the boss, fit the rubber, connect the waste pipe. That is genuinely the whole job. They are equally useful during new-build first fix where multiple waste connections need to be made efficiently and without fuss.
The boss rubber adaptor approach is also favoured where access is tight and getting a solvent weld joint properly aligned and cured simply is not practical. The rubber does the work of sealing and gripping, so there is no waiting around for anything to cure before the next stage of the job can proceed.
At under a pound each, keeping a couple of both sizes in the van makes obvious sense. Running out mid-job for the sake of a 99p part is not a good use of anyone’s afternoon.
Pro Tip: When drilling the boss hole, use the correct size hole saw for a snug fit — too large and the rubber will not compress properly against the stack wall, and you will end up with a weeping joint that is a pain to sort out later.
Boss rubber adaptors are used wherever a waste pipe needs connecting into a soil stack or branch pipe via a drilled boss. Common applications include basin, sink, bath, and shower waste connections during both new installations and retrofits. Plumbers use them on domestic and light commercial jobs where a quick, reliable connection is needed without solvent welding. They work with standard PVC-u waste pipe in 32mm and 40mm diameters across a wide range of plumbing scenarios.
Best For
Connecting waste pipes into drilled soil stack bosses
Retrofit plumbing where solvent weld is not practical
Basin, sink, bath, and shower waste connections
New-build first fix waste pipework
Compatible With
32mm PVC-u waste pipe
40mm PVC-u waste pipe
Standard drilled boss connections on soil stacks
Most PVC soil and vent pipe systems
Key Features
Compression rubber seal, no solvent weld required
Push-fit installation
Available in 32mm and 40mm
Suitable for domestic waste applications
Watertight seal under normal waste flow conditions
Not suitable for: Not suitable for pressure pipework or above-ground drainage carrying anything other than standard domestic waste. Not intended for use with solvent-welded push-fit systems where a mechanical seal is required at higher flow rates.
Drill the correct size hole into the soil stack or boss pipe using a hole saw sized to match the rubber adaptor. Push the rubber adaptor firmly into the drilled hole so it sits flush and the rubber compresses evenly around the opening. Insert the waste pipe through the centre of the adaptor until it is fully seated. Check the connection is aligned correctly before making good around the entry point if required.
Select the correct size adaptor for your waste pipe, either 32mm or 40mm.
Mark and drill the boss hole in the soil stack or pipe using the appropriate hole saw size.
Deburr the drilled hole to ensure a clean edge that will not damage the rubber.
Push the boss rubber adaptor firmly into the drilled hole until it sits flush with the pipe wall.
Insert the waste pipe through the centre of the rubber adaptor, pushing it fully home.
Check alignment and test the connection with water before completing the installation.
What size hole do I need to drill for a boss rubber adaptor?
The hole size depends on the adaptor size, but generally you need a hole that allows the rubber to compress snugly against the inner wall of the stack. Check the adaptor dimensions before drilling and use a sharp hole saw for a clean edge. A rough or oversized hole will prevent the rubber from sealing properly.
Can I use a boss rubber adaptor on an existing soil stack without draining the system?
You can drill into the stack without fully draining it, but it makes sense to time the job during a period of low use if possible. The adaptor fits quickly, so exposure time is minimal. Just be ready to work cleanly and have the rubber and pipe to hand before you drill.
Are these adaptors suitable for both 32mm and 40mm waste pipes?
Yes, but each adaptor is sized for one pipe diameter. You need to select the correct size for your waste pipe, either 32mm or 40mm. Using the wrong size will result in a poor seal, so check your pipe diameter before ordering.
Boss rubber adaptors are manufactured from flexible rubber compound designed to compress and seal against the inner wall of a drilled boss connection on standard PVC-u soil and waste pipework. The rubber material provides a watertight mechanical seal without adhesive or solvent weld. Available in 32mm and 40mm to suit the two standard UK domestic waste pipe diameters.
From £16.90£20.28 EX VATINC VAT Select options This product has multiple variants. The options may be chosen on the product page
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