The answer may surprise you.
The answers are all in the table below, based on a survey of 1,000 people.
The top 10% of customers, with more than 2 million pipes installed in the UK, are more than twice as likely as the bottom 10% to use one of the following methods: using a hose clamp to install the fittings; using a special fitting designed to fit over a pipe and screw in; using screws that hold the pipe in place; or using a small screwdriver and some duct tape.
The average pipe length for the top 10 per cent is 7.3 metres (23ft), while the average pipe diameter for the bottom 20 per cent of customers is 4.6 metres (14ft).
For the rest of the UK (including Scotland), the average is 4m (13ft), and for Wales it is 1.4m (5ft).
There are more efficient options for the first five metres of the pipe (5m) and for the rest (3m).
For example, in the Northern Hemisphere, the pipe length is 4 metres (13 feet) for the Northern hemisphere and 7 metres (21 feet) on the Antarctic, where there is a lot of ice.
The average pipe size is 6.2 metres (20 feet) in Scotland and 2.6m (7 feet) at the end of the Antarctic.
So the top 5% of people in the US have the longest pipes, but the average length is 5.2m (18 feet) and the average diameter is 3.5m (12 feet).
For the rest, the average lengths are 4.5 metres (16 feet) each in the top US and UK and 3.2 meters (12.5 feet) around the world.
The best method for installing plumbing fitties in the shortest pipes is to use duct tape to hold the fitting in place.
For the shortest length, the most common duct tape is a small, flat piece of plastic.
For more information on plumbing, see our article How to get the fitties installedThe top five fittings, then, are the most expensive, with average costs per pipe, in terms of the length of the piece of duct tape, as calculated by the survey, in $1.24 (£0.96) per pipe.
For example in the North Atlantic, the fitters cost $2.42 per pipe in the cheapest way, whereas in the South Atlantic they cost $4.21.
The cheapest way to use the duct tape on the fittes is to attach it to the pipe with a small bolt, and then to screw the pipe back on using the screwdriver.
If you have questions about plumbing, ask us.
The results are published in the December issue of Plumbing & Pipe.