Through-wall flashing, end dams and weeps
Where through-wall flashing goes in a masonry wall and how its drip, rise, end dams and weeps work; which metals published guidance supports; how a head flashing is installed and its lengths worked out; and the defects to check before brick covers it.
4 lessons · about 44 min · 11 diagrams · 1 video
Version 1.0.0
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Lessons
0 of 4 complete
Lesson 1 · 10 min · 10 slides · 7 questions
Through-wall flashing, end dams and weeps: principles and terminology
What through-wall flashing does in a drainage wall, where it goes, how it reaches and passes the face, what end dams and weeps are for, AFS's Through Wall template, and the OSHA zone around a wall being built.
You will be able to: Name the parts of a through-wall flashing assembly, say where it goes, define end dam, weep and drip, and state the safety boundary for working beside a masonry wall under construction.
Not startedStart →Lesson 2 · 11 min · 11 slides · 8 questions
Through-wall flashing, end dams and weeps: materials, standards and design constraints
Why BIA endorses stainless steel and copper and does not recommend galvanized steel or aluminum, how membranes use a metal drip edge, the weep and lap numbers and who publishes each, and what AFS can make.
You will be able to: Choose a through-wall flashing material from published guidance, state which numbers are recommendations, code limits or manufacturer values, and match them to what AFS can fabricate.
Not startedStart →Lesson 3 · 13 min · 12 slides · 8 questions
Through-wall flashing, end dams and weeps: methods and worked application
The installation sequence for a head flashing from bearing to weeps, how end dams are formed, two worked examples with every input labelled, and how sills and stepped flashing differ.
You will be able to: Set a head flashing over a lintel in sequence, form and check its end dams, work out piece lengths and weep counts from stated inputs, and flash a sill and a stepped run.
Not startedStart →Lesson 4 · 10 min · 11 slides · 7 questions
Through-wall flashing, end dams and weeps: defects, verification and case study
Missing and misplaced end dams, flashing stopped behind the face, unsealed laps, punctures, weeps in the wrong place or clogged, a pre-cover inspection card, photographs of hidden work, and a constructed case of a stained window head.
You will be able to: Recognise eight through-wall flashing defects, tie each to a published rule, check the work before it is covered, record it, and reason from a symptom to a likely cause.
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Practical task
Build a job packet for the head flashing over one window in a brick veneer wall (your own project or a hypothetical one): choose the material, work out the length and the weep count, mark up the end dams on a sketch, and write the checks you will make before the brick goes on.
Hand in
- A decision rationale: the material you chose and the published guidance behind it (BIA, a manufacturer or the specification), with the documents that govern named
- A marked-up section and elevation sketch showing the drip, the rise up the backup, the end dams at or beyond the lintel ends, the laps and the weeps
- An assumptions sheet with units: opening width, extension past each jamb, piece length, lap method and weep spacing, each labelled as from the drawings, a code, a trade body or a manufacturer
- A length and weep calculation, with the arithmetic shown, for your opening
- A defect analysis: which two of the eight defects your detail is most exposed to, and the check that would catch each before the brick covers the flashing
Rubric
| Criterion | Meets the standard when |
|---|---|
| Material | The material choice cites published guidance and does not present galvanized steel or aluminum as a recommended through-wall flashing in brick masonry. |
| Source labels | Every number is labelled as the drawings, a code limit, a trade body recommendation or a manufacturer value, and the specification is named as governing. |
| End dams | Each end that stops has a dam turned up into the head joint at least 1 in, placed at or beyond the lintel end, with its sealing or soldering method named. |
| Arithmetic | The head length is the opening plus the extension at each end, the weep spacing does not exceed the stated maximum, and the working is shown. |
| Weeps and cavity | Weeps are immediately above the flashing, open and clear, and the plan keeps the air space clear of mortar droppings. |
| Safety and record | The packet notes the limited access zone while the wall is built and plans photographs of the flashing before it is covered. |