Field & trade terms
MEP (mechanical, electrical, plumbing)
MEP is the field shorthand for the three systems that thread through a building behind its finishes: mechanical (heating, cooling and ventilation), electrical (power, lighting and low voltage) and plumbing (supply, waste and vent). On a schedule these trades run in parallel and constantly cross each other's paths, so their work is inspected in two big passes — a rough-in walk while everything is still exposed, and a final walk once devices, fixtures and equipment are set.
Why it matters
How it shows up on site
The trades share the same wall cavities and above-ceiling space, so coordination is half the job: who gets the high line, who crosses under, who owns the sleeve. An inspector checks that each system is supported, sloped, protected and clear of the others, and that anything passing through a rated assembly is sealed back up.
What proves it
Because RTI closes items on a photo, MEP rough-in is documented while it's open — supports, connections, clearances and slope shown in frame, not signed off from memory. After cover, that photo set is the only record of what's actually in the wall.
Standards it's verified against
Checklists that put mep (mechanical, electrical, plumbing) to work
Free, field-ready checklists, each with the photo every item needs before it can be submitted.
Related terms
- PenetrationAny point where a pipe, conduit, duct or cable passes through a wall, floor or roof — a hole that has to be sealed back to match the assembly it crosses.
- FirestoppingSealing openings where pipe, conduit or cable pass through a fire-rated wall or floor so the assembly's rating is restored.
- Backflow preventionA device or assembly that keeps used or contaminated water from reversing back into the potable supply through a cross-connection.
- FlashingThin sheet material lapped into an assembly to direct water back out at joints, edges and openings before it can get behind the finish.
- Vapor barrierA sheet material that limits how much water vapor diffuses through an assembly, placed to keep condensation from forming inside the wall or floor.
- Air barrierA continuous plane of materials that stops air from leaking through the building enclosure, sealed at every joint, seam and penetration.
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.