I have some preliminary plans from an architect calling for a rain screen wall for the exterior siding. At this point there are not many details, it is more just initial elevations to get a feel for the look and to start feeling out the budget.
But, the look they are going for on the siding is 1×3 cedar boards running horizontally like typical bevel siding. However, unlike typical siding, there will be a 3/16 in. space betweem each board so there is no overlap from one course to the next.
This means that the siding really does not protect the house much from water at all. The real protection from water and the elements will have to come from the housewrap or tar paper underneath.
My question is what would you guys use under this to protect the house. I would hesitate to rely on tyvek or even felt paper to be the primary defense against water. This is in Seattle, by the way. It seems to me that in a typical rain screen, the siding is furred out from the wall, but the siding is still the primary barrier against moisture. In the new proposed scenario, I would worry that the tyvek or felt paper would break down over time and would not hold up against the elements.
So far, the architect is looking for a way to make his design work and has asked me for my opinion and ideas.
What do you guys think. Any suggestions?
Thanks,
Brad
Replies
New architec? Metal flashing behind the gaps
I really enjoy working with some architects because they stretch the imagination. That is what they are trained to do. But sometimes there ideas are hairbrained. I would get the architect to change the siding or quit the job.
This firm is in fact a new firm staffed with a good bunch of young archies with some neat ideas. That is a big part of the appeal. I do mostly remodeling/renovation of older homes in Seattle. A lot of Craftsman homes, etc. For me, I'm very much looking forward to this project because it gets me a little out of my comfort zone and gets me learning some new things. Sometimes the wheel does need to be re-invented or at least jazzed up a little bit. These guys are very willing to listen to my ideas and (hopefully) constructive criticisms. As I said, we are still in the design phase so now is the time to iron out these details and come up with something that will work and give the look they want.
Even if the felt or housewrap would go the distance, those spaces between the boards would just invite critters. Sounds like bad juju to me.
Maybe if you did the rainscreen, then layered over that with aluminum coil, followed by the cedar. Many, many dollars, but what's the value of art?
Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein
"Get off your dead #### and on your dying feet." Mom
I would agree with Andy for a couple of reasons. Critters aside, what he or she suggest is not a rain screen, it's a visual baffle and nothing else.
Protection from the elements should always be a system using two different lines of defence.
Even with that most disgusting siding ever invented, vinyl, installed over house wrap, you have two lines of defence.
Board and batten over some type of wrap, brick or stone over some type of wrap, wood siding over some type of wrap....all have two lines of defence.
Each product is intended to shed the elements on it's own.
You have to always remember that the installation of both the wrap (felt paper, tyvek etc.) always compromises the product. whether you staple or nail the material on and the same goes for the nailing of the siding or installation of the brick ties, they all are compromised. This is why you have two lines of defence from the elements. The odds against putting two methods of attachement over one another is was keeps your house relatively dry and sealed.
I don't know where you're located but I can further tell you that in a cold climate, any water getting in behind your boards would freeze and within a short period of time the boards would loosen.
Find an architect who practices on his own house.
Gabe
actually, critters were the first thing i thought about. nothing like creating several thousand square feet of prime bee/wasp habitat.
I'd think you should get some sort of environmental karma credit for that <G>Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein
"Get off your dead #### and on your dying feet." Mom
bad jujuEnvironmetal karma!You need to teach a course in the new residential terminology!
be more fun than learning Spanglish
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I was of course, speaking Engelish.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein
"Get off your dead #### and on your dying feet." Mom
Could he spec cedar that has the appearance he wants, but actually is not?
That's what I was going to say... use channel siding.
No way I would ever put up plain boards with gaps as siding.
I would think that you would have to treat that situation the same way you would treat the top of an exterior door or window and that is by adding window cap flashing and door flashing across the total width otherwise it sounds like someone is trying to reinvent the wheel here.On another note what type of guarantee does the rain guard company provide and better yet what doe`s the guaranty not cover.Give some thought to ship Lapping the 1x3.....
Building on a couple of the other ideas here, how about using something like one of Benjamin Obdykes products, such as the Homeslicker, or the Homeslicker with Typar, underneath a horizontal shiplap? You could also have the shiplap milled so that the bottom of each groove is not flat, but slopes outwards. You still would get two avenues of protection, I'd trust it just as much as vinyl over Tyvek. I'd want to see that cedar primed to death and face-nailed so that it could be replaced fairly easily. You'd get very close to the right look and still have a way for moisture to get out from behind the siding.
Might even be worth using something like Grace Tri-Flex or a similar product made for roofing instead of Typar - I think it's a bit more water repellent.
thanks for the input from you all. yes, it seems to me also that the gaps betweem boards are not an ideal situation. i like the shiplap idea to get the same effect, but to give a better barrier as a first line of defense against the elements. as a couple of you mentioned, if the gaps had to stay, that would require basically having another barrier (flashing, aluminum, whatever) behind the boards and in front of the housewrap. This, of course, adds $$. There will be more discussions with the architects but I just wanted to see if there was something about the rainscreen idea that I was missing.
another thing to consider is how in the world are you going to keep the gap even and level and straight...
it will lend itself to visual inspection and none of the lines are going to be parallel
the size of the siding.. the narrow gap and the wavy nature of a a 1x3 cedar clap are going to defeat the intention of the architect
build a 4x4 mock-up and he will fast abandon this idea.. of you will convince yourself exactly how useless this isMike Smith Rhode Island : Design / Build / Repair / Restore
The exterior siding/first line of defense should be doing 95-100% of the water shedding with the rainscreen/wall sheathing membrane picking up the remainder.
Be careful with new and young architects, not much experience there and may be even less building science taught at their respective schools. The architectural discipline moved massively toward the "design/art idea" of building from the 50's on.
Front page article of June/2005 Energy Design Update was tilted "Teaching Architects Building Science". From it there is a quote (for the second time tonight quoting Bill's work) from Bill Rose's book "Water In Buildings": Rose Qqotes Max Abramovitz, the architect of the United Nations headquarters in NYC, who lamented in 1949, "Actually, I am very concerned that the science of building is going to disappear. I wonder if you realize how very few men are left today who are expert in building science. They are very rare and are passed around among the large offices. You have to dig them out of their holes and revive them."
Another quote from the article is: "What was happening in the US architecture schools from the 1950's to the current time was systematic replacement of building technology courses with courses that relate to architecture theory, history, and criticism."
Funny you should mention Water in Buildings. I just bought a copy and am about 3 chapters in. It turns out that I'd forgotten most of what I once knew about water at a molecular level. Great book so far. Bill's sense of humor keeps jumping out, even in the boilerplate sections on math and physics.Andy
"Never try to teach a pig to sing. It wastes your time and annoys the pig." Robert A. Heinlein
"Get off your dead #### and on your dying feet." Mom