"Just Move It Over a Bit."

The Reality

You get on site to rough-in and a structural beam is sitting exactly where the drawings said your stack would go. The site foreman tells you to just route around it — it's a five-minute conversation, and the job needs to keep moving, so you do it. Three months later, at final claim, that re-route is disputed as "part of the original design" because there's no written instruction anywhere that it ever happened. It happens with fixtures too. The client upgrades from a standard mixer to a feature tapware package after you've already roughed in for the original spec. You adjust on site because pulling the job up over it isn't practical. Or a hot water system gets upsized after pricing, once the mechanical engineer works out the original unit won't cover the actual load — another absorbed cost nobody formally instructed. And when another trade cuts into pipework you've already pressure-tested and signed off, you're doing rework and re-testing with no record of what was there before they got to it.

Where Subcontractors Lose Money

• check_circlePipe routing changed on site to work around a structural clash, with no written instruction that it happened
• check_circleFixture or tapware upgrades made after rough-in has already started, absorbed into the original price
• check_circleHot water system or cylinder upsized after pricing, once actual load is confirmed
• check_circlePressure-tested and signed-off pipework damaged by another trade, with no photo record of the original completed work
• check_circleGas or backflow certification and re-testing work that's never separately claimed
• check_circleAccess delays waiting on framing or other trades before rough-in or fix-off can proceed

What The Contract Actually Requires

Most plumbing subcontracts treat a re-route, fixture change, or system upsizing as a variation requiring written instruction and agreed pricing before it proceeds — a five-minute conversation on site to solve a clash doesn't remove that requirement, it just makes the paper trail easy to skip. What actually counts as in-scope versus extra varies contract to contract, so it's worth knowing your own. What's consistent: pipework photographed pressure-tested and signed off before it's boxed in is far easier to claim rework against than a memory of what was there before someone else cut into it.

How Subbie HQ Helps

• check_circleLog a re-route, fixture change, or system upsizing as an Update the moment it's agreed on site, not after the job's moved on
• check_circlePhotograph pressure-tested and signed-off pipework before it's covered or boxed in, so damage by another trade afterward is provable
• check_circleRecord additional rough-in or fix-off labour and materials via Day Works, tied to the instruction that caused it
• check_circleKeep every site conversation and email about a spec or design change in one Correspondence trail
• check_circleSend a variation for approval with a secure link the PM can act on with no login — a written approval that actually exists, not a verbal fix agreed on site

From Site Event → Evidence

Clash or spec change resolved on site → logged as an Update the same day → tagged to the relevant Site Instruction or Variation → photos and Day Works attached as the work happens → bundled into a Variation Package before the claim goes in, not after it's disputed.

Why This Matters

A twenty-minute re-route around a beam and an absorbed cylinder upsize don't feel like much individually. Across a year of jobs, they're real, recoverable margin you're quietly writing off.