Windows, doors and opening transitions · Lesson 2 of 4

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.

10 min · 11 slides · 7 questions

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Slide 1 of 11

The installation standard

ASTM E2112-23 is the standard practice for installing exterior windows, doors and skylights.

It covers fenestration products in new and existing construction, mainly residential and light commercial buildings. Use the edition your project names.

Sources

ASTM E2112-23 Standard Practice for Installation of Exterior Windows, Doors and Skylights (catalog page; title and scope only) - ASTM International (catalog entry at DIN Media)

Videos for this lesson

What this video shows: A carpentry contractor bends a simple end dam on a metal piece the video description calls a head flashing and a drip cap, over a window or door. The description says the dam keeps water that reaches it from flowing off the side. One contractor's method, not a code or AFS method.

Video: How to Bend a Drip Cap End Dam by Northview Carpentry, on YouTube. Chosen from the video's published description.

Glossary

Fenestration: A general word for windows, doors and skylights, the products that fill openings in an exterior wall.
AAMA 711, 712 and 714: Product standards the 2015 IRC, as a TechNote quotes it, requires for flashing products: AAMA 711 for self-adhered membranes, 714 for fluid-applied membranes and 712 for mechanically attached flexible flashing.
Head flashing: In the TechNote, the flashing installed at the top (head) of a window or door; self-adhesive flashing is common for jamb and head flashing. It should extend at least 1 in beyond the jamb flashing.
Cap flashing (drip cap): In Guertin's article, a metal flashing over the trim at the top of a window or door, with a wall leg, a cap leg and a drip leg; he calls it cap flashing, aka drip cap.
Jamb flashing: Flashing at the sides of an opening that laps over the pan flashing and extends above the head flange.
Cap leg: The sloped top leg of a metal cap flashing (drip cap) that runs out over the window trim; one builder slopes it outward 10° to 15°.
Polymeric membrane separator: A plastic membrane placed between copper-treated lumber and metal so the two do not touch.