As a rule if I'm measuring between two defined points then I would use which ever system is the easiest to remember, but because the work I do uses drawings that gives measurements in metric then I use those.
That depends on what trade they're in (and country).
Dealing with wood, bricks and boarding you could use imperial or metric for the odd ball sizes, but dealing with pipes is a little bit different.
Design drawing are always in metric. What size to use depends on what material the pipe is made of.
Iron is always imperial (closest size to design drawing).
Plastic waste imperial or metric (closest size to design drawing).
Copper pipe should now be metric (and matches design drawing).
All threaded fittings are BSP (British Standard Pipe) imperial sizes.
You do on the odd occasion come across imperial copper tube which you have to get imperial to metric adapters for certain pipe sizes.
And one more note: electric cabling in the UK is always in metric.
Just look on the bright side that the currency in the UK was decimalized in 1971 ( http://website.lineone.net/~davghalgh/money.html ).
The thing with building materials is that most builders indeed talk in imperial most of the time.
That depends on what trade they're in (and country).
Dealing with wood, bricks and boarding you could use imperial or metric for the odd ball sizes, but dealing with pipes is a little bit different.
Design drawing are always in metric. What size to use depends on what material the pipe is made of.
Iron is always imperial (closest size to design drawing).
Plastic waste imperial or metric (closest size to design drawing).
Copper pipe should now be metric (and matches design drawing).
All threaded fittings are BSP (British Standard Pipe) imperial sizes.
You do on the odd occasion come across imperial copper tube which you have to get imperial to metric adapters for certain pipe sizes.
And one more note: electric cabling in the UK is always in metric.
Just look on the bright side that the currency in the UK was decimalized in 1971 ( http://website.lineone.net/~davghalgh/money.html ).