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RTI

Field & trade terms

Flashing

Flashing is the sheet metal or membrane installed at the vulnerable seams of a building — where a roof meets a wall, where a window sits in an opening, where a deck ties into cladding — to catch water and shed it back to the outside. It works entirely by lapping: upper layers over lower, so gravity keeps water on the surface and out of the wall. Reversed laps or missing pieces don't leak on install day; they leak two winters later, which is why flashing is inspected before it's covered.

How it shows up on site

You see flashing at head, sill and jamb of window and door openings, at roof-to-wall transitions and penetrations, at deck ledgers and at the base of cladding. The whole game is shingle-style layering — each piece integrated into the water-resistive barrier so the drainage plane is continuous.

What an inspector looks at

The check is direction and continuity: does water hit each flashing and get thrown out rather than led in, are the laps correct, is the sill pan turned up at the back and ends, and is everything tied into the barrier rather than caulked over it. Sealant is a backup, never the flashing.

Because RTI closes items on a photo, flashing is documented while it's still exposed — sill pans, head flashing and roof transitions shot before siding, trim or roofing hide the laps for good.

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.