Architectural Flashing Supply
Start a Quote
Tier 3 · Professional Installation

Windows, doors and opening transitions

How a window or door opening is flashed so water drains out instead of in: the parts and their lap order, the standards and limits that apply, worked piece lengths, and how to find and correct defects.

4 lessons · about 44 min · 14 diagrams · 1 video

Version 1.1.5

Builds on these modules

Related Academy lessons

Lessons

0 of 4 complete

  1. Lesson 1 · 10 min · 10 slides · 7 questions

    Windows, doors and opening transitions: principles and terminology

    Why openings leak, how a drained opening works, the sill pan, the jamb strips, the pieces named at the head by TN05, Guertin and the AFS catalog, the lap order, and the fall-protection boundary at an open rough opening.

    You will be able to: Name the parts of a flashed window or door opening, explain drained installation, shingle-fashion lapping, back dams and end dams, and state the safety boundary at an open wall opening.

    Not startedStart →

  2. Lesson 2 · 10 min · 11 slides · 7 questions

    Windows, doors and opening transitions: materials, standards and design constraints

    Which standards and code text touch window and door flashing, what AFS fabricates for openings and its limits, how metal and treated lumber interact, and the shape values makers and builders publish.

    You will be able to: Identify the standards and code text that govern opening flashing, the metals and limits AFS works within, and the compatibility and shape constraints that affect a metal head or cap flashing or a sill pan.

    Not startedStart →

  3. Lesson 3 · 15 min · 12 slides · 10 questions

    Windows, doors and opening transitions: methods and worked application

    The installation sequence from pan flashing to head flashing, which sealant and tape rules belong to which product, metal pan and storefront details, and four worked examples with every input labelled.

    You will be able to: Follow the crew sequence for a flanged window with the WRB on, apply the lap and sealant rules, and work out head piece, jamb flashing and sill pan lengths from labelled example inputs while recording assumptions and units.

    Not startedStart →

  4. Lesson 4 · 9 min · 9 slides · 5 questions

    Windows, doors and opening transitions: defects, verification and case study

    Typical sill, head and jamb defects and why they fail, an inspection list to use before cladding covers the work, and a constructed case study traced to its cause and corrected.

    You will be able to: Diagnose common opening-flashing defects from their symptoms, check an opening against a written list before it is covered, and explain the corrective steps for a constructed stained-window case.

    Not startedStart →

Practical task

Choose one window or door opening, real or from a drawing. Write a one-page flashing plan: the sequence you would follow, which maker's instructions govern, the lengths of the head piece (the piece your maker or source names), jamb flashing and sill pan with every input and unit shown, and an inspection list to complete before the cladding covers the work.

Hand in

  • A numbered sequence from preparing the WRB to folding the flap down, naming the lap order at the sill, jambs and head
  • A length table for the head piece (say which piece and which source or maker names it), jamb flashing and sill pan showing the formula, each input with its unit and where it came from, and whether each piece fits within 126 in
  • A marked-up inspection list of at least eight points, with a note of which maker or source each number on it belongs to

Rubric

CriterionMeets the standard when
Lap orderPan first, jambs over the pan, head flashing over the jambs and the WRB flap folded down, following the TechNote's six steps or the maker's own, with no reverse lap anywhere in the plan.
DrainageThe bottom flange is left open to drain, the pan has a back dam or slope and end dams, and the plan says how the interior air seal avoids blocking the drainage path.
Lengths and unitsEach length follows the opening-flashing formula, every input is labelled as measured, example or from a maker, and units are shown on every line.
Source disciplineEvery tape length, sealant gap or slope is attributed to the product or author it comes from, and none is presented as code.
Safety and inspectionThe plan applies the 39 in and 6 ft test to any upper-floor opening and names the three systems 1926.501(b)(14) allows (guardrail, safety net, personal fall arrest), and the inspection list is complete before concealment.

Module quiz

10 questions drawn from a bank of 29; a new set each attempt. Pass mark 80%.

1. What does BSC say can defeat the function of a pan flashing at a window?
2. What does BSC say is needed to prevent water running laterally off a pan and into the wall?
3. Which feature of a pan flashing stops water running toward the interior of the wall?
4. What outward slope for the cap leg does the Fine Homebuilding article by Guertin give?
5. In the TechNote, how does the head flashing sit relative to the jamb flashing?
6. Where does DuPont say not to run a continuous sealant bead?
7. In shingle-fashion lapping at an opening, which layer laps over which?
8. For an inside corner in a sheet metal pan, what does BSC call the more durable technique?
9. In DuPont's guide, what must a metal sill pan not replace?
10. In which direction does DuPont's guide say sill flashing must not slope?