GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Gutterless gable house – rainscreen ventilation doubts

salf | Posted in Green Building Techniques on

Imagine a small house, with a gable roof, it would be a “barn” type of building.

Entirely wrapped in wood boards (roof included), there’s no eaves nor gutters, all rain water will be handled with a perimeter “in ground gutter”.

Walls will be be insulated with fiberglass batts, and 2″ exterior rigid foil faced, staggered and taped. The roof would be similar, cathedral ceiling, blown-in insulation, spray foam inside to seal everything, and 2 ” of rigid outside. In theory it would be pretty well insulated and air tight.

Now, the whole house would be wrapped in wood boards, forming a rainscreen, here’s my question; do I have to ventilate the ridge in order for the rain screen to work?

The only “proper air intake” it’s in the bottom, with either a insect screen or coravent strip, however the board siding isn’t exactly sealed tight between boards, it supposed to be a bit “rough”. Air (and for that matter water) could leak everywhere.

Here’s a link to a similar house in England, this is what I mean:

Thanks for any input.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. GBA Editor
    Martin Holladay | | #1

    So, you want to build a house with no roof overhangs? To me, this design is a disaster.

    I don't know what type of roofing you are planning to use -- but the roofing has to shed water at the eaves. You say that the house will have no eaves. But every roof has an eave (unless it is a low-slope roof that drains to a center drain -- another very bad idea, by the way).

    The eave of the roof is where the water drips off. The design you are looking at is scary. It looks like the roofing sheds water into the wall.

    You need roofing. At the eave, you need a drip-edge. The drip-edge is a piece of metal flashing that the water drips off of. If you draw an imaginary plumb line from your drip edge to the ground, you want that spot to be as far from your foundation as possible.

    The architect who designed this building has never worked as a roofer.

  2. user-2310254 | | #2


    I don't think this article addresses your specific concern about ventilating the rain screen, but it might be helpful:

  3. user-2310254 | | #3

    My house is currently under construction and has a similar contemporary barn profile. It is also gutterless but has fairly minimal overhangs. I've debated about whether to increase them so they extend out a couple of feet, but my aesthetic adviser probably won't go for it.

  4. user-659915 | | #4

    Martin, you're worrying needlessly. It never rains in England.

  5. Expert Member

    Sullka, avoiding the rather interesting choice of wood as a roofing material which Martin has brought up, no the roof rainscreen gap should not be connected to that of the wall. Most jurisdictions have codes mandating fire separations in cavities so that flames do not have an unimpeded path to spread. This also extends to the rainscreen which should terminate at the top of the wall. Because your design lacks eaves, venting the top of the rainscreen is probably a bad idea.

  6. Expert Member
  7. Mike Eliason | | #7


    that house may have gutters, they just aren't exposed. this is used on a lot of 'monolithic' projects in EU. can't tell from the photo how it's done. here are two built examples (gutter barely visible)

    detail is similar to this one:

    or this:

    others have TPO or membrane roof w/ gutter, but then roof is wrapped in same cladding as facade, w/ same 'open joint'. looks good usually). ain't cheap. I believe this is what studio 804 did on their house:

  8. GBA Editor
    Martin Holladay | | #8

    I think you missed my point. While Sullka referred to a "gutterless" design, I never used the word "gutterless." I said that "this design is a disaster."

    We could argue the point back and forth, I suppose, but the article that Malcom Taylor linked to -- the one from the Daily Mail in the U.K. -- makes my point for me. The headline of the article reads, “'Eco-school' that opened just THREE years ago is already leaking so badly pupils will have to go into temporary classrooms for two years.”

  9. Expert Member

    Mike, we are at point now where available technology and expertise makes almost any thing possible. But surely the pressing question is not whether it can be done but whether it is is a good idea?

    One of the threads of Green Building that seems to sometimes get lost here in an overly technical response to energy concerns are common-sense practical building techniques that work with, not against, climate and materials.

    If the first step in the design of building is choosing a form and materials that work in the climate, and these can often be taken from the vernacular that has been developed by the people who have lived there for centuries, then you don't have to rely so heavily on technical fixes to moderate against the problems you face.

    The buildings you linked to were shaped entirely by their architect's desire to project a currently fashionable image. Anyone who builds in Britain without overhangs, or the Southwest without shading, or a slab on grade in New Orleans get what is only to be expected.

  10. Expert Member

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |