Field & trade terms
Backflow prevention
Backflow prevention is the plumbing that keeps water flowing one way: out to fixtures and equipment, never back into the clean supply. Any point where potable water can meet non-potable water is a cross-connection, and a pressure drop or a backup can pull contamination the wrong way through it. A backflow preventer, sized and typed for the hazard, sits at that connection and blocks the reverse flow; the higher the hazard, the more robust the assembly the plumbing codes call for.
Run it with the Photo Gate
Rough-in plumbing inspection checklist
13 items · 24 photos required
Why it matters
A failed or missing backflow preventer can put contaminated water into the potable system, which is a public-health problem, not just a plumbing one. It's a required, testable device. Installed wrong, mounted backwards or left untested, it doesn't protect anything.
What an inspector looks at
The check is that the right assembly is installed for the hazard at each cross-connection, oriented and located per its listing, accessible for testing, and backed by a passing test where one is required. Irrigation, mechanical make-up and equipment feeds are common places one gets left off.
RTI is photo gated, so the proof is a clear shot of the installed assembly showing its type and orientation, paired with the test result: documentation that stands up long after the plumber has moved on.
Standards it's verified against
Checklists that put backflow prevention to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- MEP (mechanical, electrical, plumbing)The mechanical, electrical and plumbing trades: the systems run through a building's structure that get inspected at rough-in and again at final.
- PenetrationAny point where a pipe, conduit, duct or cable passes through a wall, floor or roof, leaving a hole that has to be sealed back to match the assembly it crosses.
- Blocking and backingExtra framing set inside walls to give later fixtures, casework and equipment something solid to fasten into.
- Weep holeA small opening left at the base of a cavity wall or window so water that gets behind the face has a path back out.
- Dry-inThe point at which a building is closed to weather: roof, wall barrier and openings sealed enough to keep water out and let interior work start.
- Control jointA planned weak line cut or tooled into concrete or masonry so shrinkage cracks form where you want them instead of at random.
Knowing the term is step one. Proving it is the job.
RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.
30-day trial · No card required