Replies

1. 
   Lansdown | Sep 23, 2008 12:17am | #1

   Obdyke slicker looks like great stuff. I researched it quite a bit, but ended up not using it, though I regret it. Spoke to a few people who did use it and got positive feedback.

2. 
   mike_maines | Sep 23, 2008 12:22am | #2

   Tyvek has a version of their product that's somewhat corrugated.  If you live where it's not too humid too much of the time, it should work fine.  Another option is to run strips of wood vertically or horizontally, depending on what kind of siding you'll be using.

   One note of caution--cedar and Tyvek may not get along.

1. 
   shelternerd | Sep 23, 2008 01:49am | #3

   We recently did use the tyvek crinkle wrap rain screen under some hardi board we were using due the cheaper cost than the rainslicker which is the premium product here. But last summer we did one where we gathered all the left over scrap 1/2" OSB and ripped it to two or three inches and tacked it up and that was a much better solution I am sure. The tyvek stuf was about $500 for the house we were doing, the Rainslicker would have been well north of a thousand, possibly over 1,500. OSB scrap, free plus the labor, had we run out we probably would have started running the old form boards and stuff through the table saw but we had enough scrap on the job to do what we needed. a 4x8 sheet ripped to 2" strips makes about 184 lf odd scraps work great, it's just a spacer, your still nailing through to the studs unless your shingling in which case your stapling to the sheathing. Precision is nil except around window and doors and the kicker strip at the bottom of the wall which should be insect tight. so it goes really fast. Paul Eldrencamp had a great letter to the editor published in Coastal Contractor a while back which I think is, to this day, the best ever explanation of how rain screens work. I think he should expand it and publish it on his website or in FHB but until he does you can send me an e-mail off line and I'll forward it to you as a PDF. (don't want to get in trouble with the censors by posting another magazine's content here) ------------------

   "You cannot work hard enough to make up for a sloppy estimate."

1. 
   reinvent | Sep 23, 2008 02:50am | #4

   "(don't want to get in trouble with the censors by posting another magazine's content here)"Never stopped me.http://www.coastalcontractor.net/cgi-bin/article.pl?id=135

1. 
   shelternerd | Sep 23, 2008 03:19am | #5

   That link goes to Mike Guertins article, to me Paul Eldrencamps letter to the editor in reply to Mikes article is where the meat is. Paul Eldrenkamp
   Byggmeister, Inc.
   Newton, Mass.Drainage vs. Drying
   I liked Mike Guertin's article on sidewall shingles ("Best-Practice Wall Shingles," May/June 2007). I have to dissent, though: He says that if you're using furring strips to create the air space behind sidewall shingles, "back kerfs are essential for allowing drainage and airflow between the horizontal strips." The expense of these kerfs has dissuaded him from using furring strips. In my experience, his concerns are unfounded. We've been using horizontal 1x3 strapping to batten out wood cladding — not only shingles, but vertical tongue-and-groove and shiplap siding as well — for nearly 20 years now. We've never bothered to back-kerf and, having monitored a range of such projects (including my own home) during those two decades, I can say with great confidence that lack of back-kerfing has never caused a problem. The building science behind the idea of the air space behind wood siding still seems rather fuzzy even to the top researchers. I've been hearing about the air space for 20 years now at a range of conferences and symposia, and the rationale for it keeps shifting. At first it was all about air pressure equalization; from time to time about moisture and temperature consistency on both faces of the siding; now, apparently, it's all about drainage. The fact is, if you have so much water getting behind your cladding that you really need significant "drainage," then you've probably got some serious issues that even the best-designed building envelope could have problems handling. A good exterior wall assembly, for the most part, needs to deal with only moderate amounts of water getting where it doesn't belong, and in my experience it deals with that water by giving it a chance to evaporate before the water does any real damage. It turns out water can take a pretty long time to evaporate before it does any damage, if I'm properly interpreting moisture meter readings I've taken over time on a range of projects we've done. What seems more important than quick drying is even drying. A piece of wood that does not experience wide moisture variations within itself seems to hold a coat of paint much longer than if there's significant variation from one point to another. My experience indicates that the mere fact of a sizable air space behind your wood siding seems to be enough to ensure even drying — whether or not there's significant drainage allowed for (there's always going to be some drainage, planned or not) and whether or not it's vented. This is important because placing an unwarranted emphasis on drainage or on venting will add costs incommensurate with the benefit. I would be keenly interested (and, I have to admit, surprised) if anyone knows of a situation where wood siding failed because it was installed on an air space that was unvented and "undrained." Another big factor in how long exterior wood siding lasts, not specifically mentioned by Mike, is whether the siding is sealed on all sides prior to installation. We have found that wood siding primed on all sides and installed over an air space can hold a coat of paint for at least 15 years — and still counting, with no sign of losing adhesion. This has been true not only of shingles but of clapboards and tongue-and-groove boards. This is important in the context of the article because siding that holds a coat of paint longer will also keep water out of your walls longer. Thanks very much for a great magazine. Paul Eldrenkamp
   Byggmeister, Inc.
   Newton, Mass.
   ------------------

   "You cannot work hard enough to make up for a sloppy estimate."

1. 
   reinvent | Sep 23, 2008 09:02am | #6

   Thanks for that. I could not find Paul's response so just posted the main article which I thought was relevant to the thread.

2. 
   robdog | Sep 24, 2008 03:44am | #7

   hey, thanks y'all!  i am nailing vertical rough cut pine, 1x12, over tyvek and then 3in battens over the joints....i will have huge roof overhangs...3ft on the eaves with a 8/12 pitch and 3ft on the gables...story and a half.. 

   AND...i'm not going to paint anything!  just let the rough cut siding weather to a nice old blue stain....  so at any rate, on this one i'm not concerned about the paint...i am concerned about 'drainage" and 'drying'...to protect my wall structure....horizontal furring strips would be cheap (yeah, i've got stacks of scrap osb) but i'm afraid that the horizontal strips will trap water.......

    

   thanks again for comments

3. 
   shelternerd | Sep 24, 2008 05:22am | #8

   I feel really comfortable that the horizontal OSB furring will not see enough water to be an issue but there are many who rip 1/2" battens out of treated 2x10s on a table saw (straighter and easier to deal with than the 2x4's) I just think that, as well as those ventilated plastic spacers, the Benjamin Obdyke and Enka-mat products or back-kerfed battens are overkill and not worth the effort. I also believe that it is not necessary to ventilate the space, just keep the wasps out and break the contact between the back of the siding and the drainage plane material. But this is just my opinion based on my own thirty years in the business but not on any laboratory tests or anything.------------------

   "You cannot work hard enough to make up for a sloppy estimate."