[East coast window cleaning Services]

First im gonna run a coldwater feed from the loft down the side of the house, correct me if im wrong but will it be better to use 15mm copper pipe instead of 22mm as will be better for pressure of of tap?

[007 or what]

I'd like to know the answer to this

[JM123]

it won't make one iota of difference to the pressure.  everyones tap pressure is dependent on how far below the water reservoir their house sits.  2ft = 1psi

bore diameter will only affect flow rate, but 15mm is more than enough.

[chris@c.m.s]

Depends on how the plumbing on your house is set up.
most new builds have all the cold feed direct from the mains,
where as older properties may only have the kitchen sink fed from the mains, If you want the benefit of the full pressure from the mains supply, then connect to the pipe that feeds your cold supply to the kitchen sink.  15mm is ample.

[Biscute]

Use 15mil m8. It makes no diffrence apart from drilling through brick will be easyer. But i wouldnt take it from the loft, i take it you have an old system as combi boilers dont have a top fed tank, so more than likly you are going to get a combi boiler soon rendering the top water tank usless and more often then not taken out.

[JM123]

mains pressure is dependent on the conditions I've already mentioned above.