Fittng a soil pipe boss?

14 Nov 2005
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United Kingdom

I need to fit a connection to my internal 110mm soil pipe for my shower drain. A few question please:

1. The drain will be 40mm solvent type pipes. Will the hole I drill in the soil pipe be 40mm or more/less?

2. What is the best type drill for accurate cutting?

3. Can one buy a 40mm boss? Any reccommended ones?

4. When I fit the boss I understand that theres a strap/nut-bolt for securing. But will I also need to add some silicon etc?

Thanks in advance ... Mick
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A holesaw with arbor will be fine - get the cheapest set from diy store with multiple circular blades.

Cut the hole and rough up the surround with sandpaper (for glue)

Use solvent glue to fix boss strap to pipe, tightening the strap at this point. Don't be stingy with the glue.

Use a 40mm rubber adaptor to fit pipe into hole - use silicon lubricant or even a bit of washing liquid to help. (
Thanks for the reply mate.

So am I right in thinking that there's no 'dedicated' 40mm boss? That they come in a standard size and adaptors need to be used?


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