Water pressure is rubbish upstairs, is it the pipes or something else?

[julioboyd]

Our upstairs shower has the weakest pressure I've ever experienced and it's been like this since we moved in, though I kept telling myself it was just how older houses are. Now that we've finally got the bathroom on the list for next year I figured it's worth understanding the cause before I start getting quotes, because I'd hate to spend on new fixtures and find the problem was never the shower head at all. A neighbour reckons it's the old galvanised pipes narrowing over time and that half the street has had theirs replaced, but he also told me his cousin could fix my car over the phone so I take his advice with a pinch of salt. What I'm actually after is an Expert plumbing contractor across Palo Alto who can tell me whether a repipe is genuinely needed or whether there's something simpler going on, because the quotes I've had so far have ranged from a minor adjustment to a full replacement with no real explanation either way. Has anyone here dealt with low pressure and did replacing the pipes actually fix it, or did you find the issue was somewhere else entirely? Also curious how disruptive a repipe is when you're living in the house, because the thought of open walls for a week with a toddler around is not filling me with joy.