https://www.energyvanguard.com/blog/moisture-and-the-quirkiness-of-osb/ Building science knowledge, HVAC design, & fun Tue, 21 Dec 2021 00:42:30 +0000 hourly 1 https://wordpress.org/?v=6.6.2 https://www.energyvanguard.com/blog/moisture-and-the-quirkiness-of-osb/#comment-7487 Tue, 16 Sep 2014 02:20:47 +0000 http://energyvanguard.flywheelsites.com/?blog_post=moisture-and-the-quirkiness-of-osb#comment-7487 Baffle them with Charts and
Baffle them with Charts and Grafts, but it still remains OSB is Pure Crap

]]> https://www.energyvanguard.com/blog/moisture-and-the-quirkiness-of-osb/#comment-7486 Thu, 28 Aug 2014 20:54:28 +0000 http://energyvanguard.flywheelsites.com/?blog_post=moisture-and-the-quirkiness-of-osb#comment-7486 Very interesting! The
Very interesting! The question that was going through my mind while reading was how do you know what materials and how the OSB constructed. I’m going to go to Lowes and Home Depot to see if they have descriptive literature.

]]> https://www.energyvanguard.com/blog/moisture-and-the-quirkiness-of-osb/#comment-7485 Thu, 28 Aug 2014 16:54:23 +0000 http://energyvanguard.flywheelsites.com/?blog_post=moisture-and-the-quirkiness-of-osb#comment-7485 Thanks for the recap for
Thanks for the recap for those not at camp! 
I also recently heard from a fellow Passive House architect that some OSB–apparently the stuff made from soft Southern wood–is not airtight, at least to PH levels. Before cutting in windows they couldn’t get below 0.9ACH50. It’s not all created equal?

]]> https://www.energyvanguard.com/blog/moisture-and-the-quirkiness-of-osb/#comment-7484 Thu, 28 Aug 2014 01:44:13 +0000 http://energyvanguard.flywheelsites.com/?blog_post=moisture-and-the-quirkiness-of-osb#comment-7484 My main takeaway from Mr.
My main takeaway from Mr. Timusk’s presentation at summer camp is that OSB will never return to original factory dimensions once undergoing one or more wetting/drying cycles. I have seen composition roofs in my area show elongated “humps” through the shingles, where apparently at each seam between OSB panels the material swelled up and never returned to original size. While I have long thought the irregularities in the roof decking were moisture related, I did not know about the characteristic of the OSB not returning to its former size. 
 
Thanks for blogging about Timusk’s presentation; it was among my favorites at camp, along with Hal Levin’s IAQ insights and Graham Finch’s osmosis of cold applied roofing membranes.

]]> https://www.energyvanguard.com/blog/moisture-and-the-quirkiness-of-osb/#comment-7483 Wed, 27 Aug 2014 20:31:56 +0000 http://energyvanguard.flywheelsites.com/?blog_post=moisture-and-the-quirkiness-of-osb#comment-7483 John K.:
John K.: Thanks. Yes, he did talk about swelling due to moisture. Soaking in liquid water induces a lot more of it (~20-30%) than high relative humidity (~7%), but they both have an effect. I thought about including that but decided against it because the article was already long. You can read all about it in Prof. Timusk’s dissertation, which you can download with the link above.

]]> https://www.energyvanguard.com/blog/moisture-and-the-quirkiness-of-osb/#comment-7482 Wed, 27 Aug 2014 20:26:22 +0000 http://energyvanguard.flywheelsites.com/?blog_post=moisture-and-the-quirkiness-of-osb#comment-7482 Allison: Good article.
Allison: Good article. Looking forward to the sequel. Did the report mention any dimensional changes? Seems to me from observation that the thickness increases very slightly. The OSB lightens in color and its surface gets a little fuzzy too. Anyone else observe anything similar?

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