Guys, This is great! it's one of the most lively threads on here in quite a while. One of the posts commented on how he agreed with some of the things I said but how I couldn't have communicated it in a worse way! He is probably right! Slick will probably never be one of my attributes.
As far as the Tyvek..I was not aware that there was a specific issue with the product as far as being used with cedar, although most all of the failures I have seen are with cedar. Some of the failures were with vinyl some were with pine. I had asked a rep from Tyvek about the moisture problem and he basically confirmed what I had been seeing without actually admitting it, after all it's his job to sell the stuff. I do recall reading an article in Fine Homebuilding that was written about cedar siding application. The author made note of the fact that he was using felt and not Tyvek and then he gave his reason, which had something to do with the jury still being "out" on the product. I have nearly every issue of FH since the publication started and I couldn't find the article again!.
In fairness to the product, it is a great air infiltration barrier. That's what it was designed to do. Add to that the ability to apply it to large areas of frame wall before the walls are stood, its' resistance to wind when only attached with conventional staples and it sounds like a winner. In that respect the product presents several advantages for the builder, but not necessarily the building. As stated before, I'm a remodeler, that means I take lots of houses apart in order to remodel them. I started seeing failures on projects that were barely 10-15 yrs old. Whether opening up a building to add on or simply doing maintenance, I found a common condition that the wall sheathing behind the Tyvek was usually waterlogged and often rotted. Is that a problem for because of the Tyvek or because water got behind the siding? I thought about this...but I was finding rotted sheathing in the middle of walls and such and the damage was always worse at the sheathing and face of the studs and then diminished as you moved toward the inside of the frame wall. This led to the conclusion that the moisture was more prevalent at the outer parts of the wall than the interior. The product was advertised as being able to stop air infiltration while allowing water vapor to go through, a good characteristic, if the source of the water vapor is the interior of the building. Building interiors are a source of moisture, bathing, cooking, breathing all generate moisture. Moisture wrecks the effectiveness of fiberglass insulation, hence the vapor barrier applied to the product or the poly sheet used over unfaced insulation. So the only conclusion I could arrive at is that the source of the moisture is weather related and the vapor gets through the house wrap. Now what if the moisture is the result of a breach in the sidewall material? Thats where my comment about "bandwidth" came from. No breaches in the sidewall and trim...no problem, maybe, maybe not. The realities of buildings are that they are seldom static, heat, cold, seismic activity, wind, rain snow, all take their toll on a structure. The breach is inevitable and it is subtle at first. Now what if the building was wrapped with a material that would protect the sheathing, and stop air infiltration as well? You have a building more tolerant to the inevitable. To take the stance that water should never get behind the the sidewall material is somewhat short sighted. It happens. Every time wind driven rain hits a piece of J channel it does a 180 and runs behind the siding. It gets in around window and door casings, why else then do we do these elaborate wraps on the sill surface and jack studs with felt or flashing tape. Why do some craftsmen fabricate copper flashing pans that install at the base of exterior doors. In fact one of the latest nifty products is a plastic system that is adjustable for width that forms a waterproof tray with a sloped floor to channel water away from the building frame at window and door openings. Water happens. Caulking can bite you in the backside as well, follow this... we make nice neat joints,caulk them, paint everything real pretty, looks great, right? Well go back to the part about buildings not being static. You get a failure somewhere in the caulk, you probably can't even see it. Why does the caulk fail? Most of the joints we caulk are too small for the caulking. In order for caulking to work, it needs to stay flexible AND adhere to both sides of the material comprising the joint. Every caulking material has a limit as to how far it will elongate when stressed. For any given joint, once the movement of the joint exceeds the elasticity of the caulking material, the caulking will pull away. All other things being equal, if you have a caulking material that can stretch 100%, an eighth inch joint could go to a quarter inch and be within the working limits of the material. A 1/32nd joint could go to a sixteenth before it lets go. Usually we don't end up with eighth inch gaffes that we bury in caulking, but the 1/32nd stuff? Sure! its common! Will a 1/32nd joint move enough to become a 1/16th joint? You bet. The caulk fails, water gets in, guess what, it goes somewhere else and can't get out...everything is caulked. Rot, mold etc is sure to follow. This is one of the reasons that Andersen specifies a quarter inch caulk joint between their window jambs and the exterior trim you add around the window. Now a quarter inch when doing exterior "finish" seems big enough to drive your truck through, but that's what they specify because they know the joint will not fail.
I sure upset a lot of folks who have embraced the new and "better". But remember that the Romans thought lead plumbing was the cats *** a few centuries ago.
I have no doubt as to the the energy efficiency of the buildings discussed here. The point I was trying to make is that there is more to a building than just what you spend on fuel. Sometimes, buildings are like Hot Rods, you modify the original design with a particular performance goal... and sure enough, your car is a rocket, but maybe it can't idle 10 minutes in city traffic without hurling antifreeze all over the pavement.
The structures we create today are subject to the same caveats. The degree to which the longevity and maintenance issues of any particular structure will be impacted is unknown. Rest assured we are building structures that are much more fussy as to what they will tolerate than even 20 years ago. Terms like "sick building syndrome" come to mind. Everything is so finely tuned with respect to the performance of certain aspects of the building that if anything gets out of whack, it can have extreme consequences both to the structure and its occupants. We now have to contend with blower door tests, dedicated make-up air systems, air to air heat exchangers, radon mitigation systems and the like. I am confident that over time, these devices will be robust and commonplace (not to mention only serviceable by qualified technicians). Some of the stuff that is new today will certainly benefit all of us, some of it just lines the pockets of the manufacturers, some of it will come back to haunt us.
So guys, build with wild abandon! The garage may be the "last frontier" for manhood in general.
