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!
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
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.
Solvent weld and pushfit stuff is completely different size wise. It
just LOOKS yhe same when you rush into the BM to get a spare bit, late
You wouldn't believe the bits of pipe I have glued together to make
things connect up...
TBH I almost always use pushfit; I really can't recall the last time I
had a problem with it leaking. Has a big advantage over solvent weld
that it's demountable. Certainly plenty of plumbers use it, too.
(certainly solvent-weld kit is by definition of a different size, but
even within push-fit/compression systems there are different sizes, too
- although AFAIK theoretically there shouldn't be).
Not heard that and I doubt its true. In fact your post shows you don't
recognise that push fit polyprop pipe is a slightly different size to most
solvent weld pipe which is a uPVC material. Actually Marley once did, maybe
still do, a range of push fit fittings to work with uPVC pipe. These are
all to (different) BS standards which I don't keep in my head but maybe
someone who does will be along soon. The particular standard is marked on
the pipe and fittings so check your items are to the same standard. Think
most Wickes stuff is Hunter Plastics so check out the manufacturers website.
There has been a recommendation to use solvent weld. Well if you do make
sure you incorporate at least one push fit joint for expansion. Personally
I have never heard of leaks on properly installed push-fit. One important
difference is that polyprop is not UV resistant and needs painting if used
outside but ABS or uPVC is UV resistant.
Push fit and solvent weld use different pipe, push fit pipe isn't
I'd expect that using solvent weld pipe for push fit could be asking
for trouble too.
Looks like compression uses push fit pipe.
Have a look at:
I think my OP was a little mis-read in some instances. I personally do
not use pushfit/compression-fit, from Wickes (or any other
manufacturers) in my installations and prefer solvent weld.
However, I often have to connect up to these systems on jobs I'm asked
to perform, either to add or repair something. And usually, when this
happens, the nearest Wickes is miles away and local PM's seem not to
stock suitable fittings to make the join, apart from 1 1/2" band
seals, which is what I usually end up using... not ideal when I want
to join on to something like a T.
It can be a real pain.
And I'm still in the dark about the standard sizes of boss connections
that I come accross... how many are there?
There are two BSs (5455 and 5454) covering this pipe and what's worse
quite a bit of non compliant stuff around.
The solvent weld is more popular with the more experienced. It's easy and
100% sound. It's only downside is that you do it right or you start again.
The push fit needs better support. Compression fits both standards.
It is strongly recommended that you obtain pipe and fittings from the same
supplier. There are some considerable size variations between
manufacturers even within the same standard. Leading me to believe that
not all of it is compliant.