Reducing pipe size for shower

[aljenks]

Hi, this is my first post here. I am fitting a shower mixer valve and need to run the hot and cold pipes in the wall. The wall has been plasterboarded ready for tiling and behind it there is a plastered bricked wall. My question is if I reduced the pipe size down from 15mm to 10-12mm for the pipes running in the wall will this make much of a difference on the shower head pressure? It will be running off a combi boiler system.

Thanks
Alex

hi. to be sure , contact the manufacture of the shower valve and their technical department will tell you.

[uug197h]

keep them at 15mm. if there going in the wall you need to cut in to the wall anyway so use the right size