A gutter outlet is the small fitting that lets water pass out of the gutter and into the downpipe below — get the profile or thread wrong and it either won't seat properly or will leak around the join. Blue Mountain Co's range covers the common Australian gutter profiles in both thread types, all inexpensive enough that getting a spare of the right one on hand costs very little.
Round outlets
The Round 75mm Male ($2.14), Round 90mm Female ($2.14) and Round 90mm Male ($3.25) suit the common round quad-style gutter profile. Male vs female just refers to which way the outlet's spigot fits the downpipe fitting above it — check the fitting it has to mate with before ordering, since getting this backwards means it won't seat.
Half-round outlets
The Half-Round 90mm and Half-Round 100mm (both $3.25) are built for curved, classic half-round gutter profiles rather than the squared quad style — a different gutter shape needs a different outlet, not just a different size.
Rectangular outlets
The Rectangular 100mm x 50mm ($2.60) and Rectangular 100mm x 75mm ($2.92) suit box or rectangular downpipe profiles, common on older homes and some commercial fascia gutter systems.
Choosing the right one
Three things decide the right outlet: the gutter's profile (quad/round vs classic half-round), the downpipe's shape (round vs rectangular), and the thread/spigot fit (male vs female) to whatever's connected below — a diverter, a first flush unit, or a plain downpipe. Mismatch any of the three and the outlet either won't fit or will need extra adaptors to make it work.
These outlets sit in our Downpipe Diverters & Outlets collection alongside the diverters covered in our downpipe diverters guide, part of the wider Blue Mountain Co rainwater harvesting range.
Frequently Asked Questions
What does male vs female mean on a gutter outlet?
It refers to which way the outlet's fitting mates with the downpipe component below it — a male outlet has a spigot that inserts into a female socket, and vice versa. Check what the fitting below needs to mate with before ordering.
My gutter isn't quad-shaped — do I still use a round outlet?
No. A curved, classic profile gutter needs the Half-Round outlet, not the Round one, even if the downpipe size matches.
Do gutter outlets fit any downpipe diverter?
They need to match both the gutter profile and the downpipe shape/size of whatever's fitted below — a round outlet won't mate with a rectangular downpipe diverter.
Are these outlets only for rainwater harvesting setups?
No — they're a standard gutter-to-downpipe fitting whether or not the water is being diverted to a tank. They're just especially relevant here because every diverter and first flush unit downstream needs the right outlet feeding it.