On 2007-10-05 00:42:51 +0100, deano said:

I've heard mention, in the past, that Wickes use a sizing standard,
for their waste and drainage products, that differs from those used by
competing, and perhaps more established, manufacturers such as Anchor
Plastics, in order to secure future sales of their own products, when
installations using them need to be modified, repaired or extended!

Is there any truth in this or have my past problems, involving Wickes
waste products, been due to the simple fact that Wickes' push-fit and
compression fit systems use a smaller diameter pipe than other 1 1/2"
and 1 1/4" products, meant for solvent joins? And, if so, is Wickes
the only place where you can buy a coupling to join the differing
gauges? Plumbers merchants are always stymied when I describe the
problem, yet you'd think they must hear it often!

Adding to my confusion, neither of the 2 types of boss inserts/
adaptors I bought today would fit into the boss on the in-situ branch
T! Even though the merchant said it would definately be one of them,
they both had the same OD as that of the boss housing on the T! Is
this a Wickes oddity or am I missing the obvious?

I'd like to get this cleared up once and for all, as it always
presents me with a problem, each time I encounter it!

cheerz.
d.

TBH, I don't think this is worth investigating.

There's not really any value in using push fit and compression fittings
in general because they have a tendency to come apart or leak, except
at traps where compression fittings are used.

The simple solution is to buy 32mm, 40mm solvent weld pipe and fittings
and be done with it. Every plumbers merchant has these because that
is what is commonly used. it's not surprising that they don't asked
about various makes of stuff sold in retail supermarkets like Wickes.
As you've discovered, there's a real mishmash of stuff and incompatible
sizes.

You can avoid the problem by not going to Wickes and by using solvent
weld fittings. They are neater in any case and not exactly hard to use.