Base flashing, counterflashing and reglets
How a roof-to-wall joint is installed: base flashing terminated up the wall, counterflashing lapped over it from a reglet or receiver, the documents that set each height, lap and spacing, the silica and fall rules for the crew, and the checks that catch the recurring defects.
4 lessons · about 38 min · 8 diagrams · 4 videos
Version 1.0.0
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Lessons
0 of 4 complete
Lesson 1 · 9 min · 10 slides · 6 questions
Base flashing, counterflashing and reglets: principles and terminology
Why a roof-to-wall joint has two layers, the trade terms an installer meets on details and specifications, the families of counterflashing termination, one-piece versus two-piece, the code duty to flash, and where AFS work ends.
You will be able to: Explain the two-layer logic of a roof-to-wall joint, define base flashing, termination, counterflashing, cap flashing, reglet and receiver, name the ways the counterflashing top edge is held, and state the fall-protection boundary for the crew.
Not startedStart →Lesson 2 · 9 min · 10 slides · 6 questions
Base flashing, counterflashing and reglets: materials, standards and design constraints
Which document decides each number at a roof-to-wall joint: code, project specification, roof manufacturer and reglet manufacturer. Metal minimums, heights, laps, wedges and fills by source, reroofing reuse rules, and the OSHA silica and grinder rules for cutting reglets.
You will be able to: Name the documents that govern a roof-to-wall termination, compare the metal minimums, base flashing heights, laps, wedge spacings and fills they set, apply the reroofing rules for existing counterflashing, and state the silica and grinder rules that apply when reglets are cut.
Not startedStart →Lesson 3 · 11 min · 12 slides · 6 questions
Base flashing, counterflashing and reglets: methods and worked application
The installer's sequence from layout to fill: marking and cutting the reglet, the deck-versus-roof-surface datum trap, base flashing and termination bar, manufactured reglets, setting, lapping and cornering the counterflashing, and five worked calculations.
You will be able to: Follow a documented installation sequence for a regleted counterflashing over a membrane base flashing, check reglet height, lap and clearance from the finished roof surface, and work out pieces, wedges, termination-bar fasteners and dust-collector airflow with every assumption recorded.
Not startedStart →Lesson 4 · 9 min · 10 slides · 6 questions
Base flashing, counterflashing and reglets: defects, verification and case study
The defects that recur at roof-to-wall terminations, what correct looks like, the chimney side that fails most often, field inspection and records, owner maintenance, and a reroof case study where added insulation leaves the existing reglet too low.
You will be able to: Recognise the recurring roof-to-wall termination defects and their causes, verify an installation against its governing documents with measured values, and diagnose a reroof where the existing reglet no longer fits, documenting the evidence and the corrective options.
Not startedStart →
Practical task
Document one roof-to-wall run (a parapet, wall or chimney side you can measure or a drawing you are given) as an installation packet: the governing documents, a reglet layout checked from the finished roof surface, the piece, lap and wedge plan, the safety controls, and an inspection record with one defect diagnosed.
Hand in
- A marked-up section sketch showing deck, roof build-up, base flashing and its termination, reglet or receiver, counterflashing, lap and bottom clearance, with the datum written on it
- A table of every number used (base flashing height, lap, clearance, reglet depth, wedge spacing, end lap, termination bar spacing), each with the document that sets it
- A piece and wedge plan for the run using the AFS 10 ft standard piece (and the 10 ft 6 in maximum where the specification allows it), with the arithmetic shown
- The safety controls named by regulation: fall protection under 29 CFR 1926.501 and the Table 1 silica controls under 29 CFR 1926.1153 for the cutting method chosen
- A completed inspection checklist with measured values, plus one defect (real or given) with its cause, two corrective options and the evidence you would record
Rubric
| Criterion | Meets the standard when |
|---|---|
| Governing documents | Every number names the document that sets it; where documents disagree, the packet says which one governs this job and why. |
| Datum and layout | Heights are measured from the finished roof surface, the deck datum is converted where a specification uses it, and the reglet sits above the base flashing top with the lap and clearance checked. |
| Arithmetic | Piece counts, wedge spacing, termination bar fasteners and dust-collector airflow are worked with units and every assumption labelled. |
| Safety | Fall protection and silica controls are named by CFR paragraph and match the task; no dry sweeping or compressed-air cleaning is planned. |
| Defect diagnosis | The defect is traced to a cause, the options are realistic for the installer and designer, and the evidence list (photos, measured values, document) would let a reviewer check it. |