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Detailing for inset windows when using vertical siding

Mark_Nagel | Posted in General Questions on

I tried conjuring an answer from the archives but ran out of breath: there were several threads with vertical siding but the windows were face mounted.

I’m looking on best practices for detailing recessed windows when using vertical siding.  More accurately, the detailing of the outer edges where the openings and siding planes are to meet.

I can kind of guess but I don’t want to throw myself out into the weeds.

I’m NOT set on vertical siding (I’ll have this discussion with an architect; but in my mind, which has a fair sense of aesthetics, vertical siding seems to be the right call [I’ll also have to have this discussion with my wallet!]).  I’ve thought about metal siding and then dismissed it, but have once again ruled it on the table.

Not sure that it’s the same issue with doors as they have their frames which would get set to meet up with the plane of the siding.

And though slightly different, what about mounting blocks? (these seem to be more straightforward to me, but would appreciate any pointers that could lessen any pains here).

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  1. Expert Member
    Michael Maines | | #1

    Mark, there are various ways to do it. What climate zone are you in? What details do you have in mind for:
    Rainscreen, including ventilation at bottom and/or top?
    Roof overhang?
    Window casing?
    Siding material?

    Not all will matter on every project, but they all matter on some projects.

    For mounting blocks do you mean for light fixtures and wall caps (aka vent terminations) or something else?

  2. ERIC WHETZEL | | #2

    Hi Mark,

    You can see how we detailed our windows and doors with vertical siding towards the end of this blog post:

    Most of these elements came from this presentation by Bronwyn Barry:

    It's definitely worthwhile to do a mock wall assembly with a window opening and a penetration for HVAC. This allows you to work through all the details for air sealing, water-proofing, and flashing (and any potential problems) before you're building for real on your actual house.

  3. Mark_Nagel | | #3


    It's mostly about how to trim around the openings (and seal that trim) than about window sealing per se. Yes on the mounting blocks: for light fixtures, vent terminations and electrical service entry panels [service meter box and the now required -2020 NEC- disconnect box]): with mounting blocks direct sealing IS an issue (I know that I'd want to provide a top flashing, but after this my head starts drawing blanks).

    Exterior wall, current, design is plywood (1/2" or 5/8" TBD) sheathing with applied liquid WRB, 3" (2 1 1/2") Comfortboard, rainscreen (TBD) and some flavor of vertical siding (TBD).

    Eric, hi!

    Yes, your info is excellent. It's close to addressing my concerns, though I'm still struggling. The frame-less look is nice. Siding that I am considering is a little more, for a lack of a better descriptive, bumpy. Board and batten or perhaps a metal siding (ribs, though I sure would want lower profile ones). The look and general issue that I'm pondering shows up best in slide #22 in that Bronwyn presentation.

    Metal siding seems to introduce puzzles in my head. I can get around wood-to-wood (and even the metal-to-wood, with the metal being just the sill), but the trimming of the verticals for metal siding, I'm just not sure what material (keeping in mind that function has to come first!).

    I will for sure play around with some sort of mock-up if I can't get my head around it: I'm pretty good about being able to go through physical actions in my head. I'm trying to solve ALL possible puzzles before even attempting to put a puzzle together :-)

  4. maine_tyler | | #4

    I did something somewhat similar to Eric with the double layer of rainscreen strapping. Effective but probably not the simplest solution in the way I integrate the windows.

    This is a double stud wall with 'in-betweenie' windows. I ended up pre-making trim bucks out of Boral with a pseudo traditional sill appearance. A bit of work to be sure. The trim gets screwed into the 1x4 strapping from the side and caulks to the window. Not all needed flashing is shown in the images, and the final trim (painted pine) isn't actually installed in the last pic, but gives an idea.

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