{"id":112,"date":"2013-03-20T16:34:36","date_gmt":"2013-03-20T20:34:36","guid":{"rendered":"http:\/\/ipedepot.com\/deckblog\/?p=112"},"modified":"2013-04-02T11:43:37","modified_gmt":"2013-04-02T15:43:37","slug":"what-moves-wood","status":"publish","type":"post","link":"https:\/\/www.ipedepot.com\/deckblog\/what-moves-wood","title":{"rendered":"The Science Behind the Expansion & Contraction of Wood"},"content":{"rendered":"

Why Wood Moves<\/strong><\/p>\n

Like many building materials, wood expands and shrinks. This is due to how much moisture is in the air.\u00a0 If there\u2019s high humidity the cells within the wood will expand.\u00a0 If there is low humidity, the cells will shrink. Thankfully there is a way of predicting how much the wood will shrink or expand.\u00a0 The equilibrium moisture content (EMC) is basically the length of time it takes for your wood to accommodate to its new environment.\u00a0\u00a0 It can tell you whether your wood is going to expand or shrink.\u00a0 The EMC helps us understand the response wood has to relative humidity (RH).\u00a0 For example a change in Moisture content (MC) will cause a 12 inch wide maple board to expand or contact by at least \u00bc inch.\u00a0 The graph below gives examples of MC versus RH.<\/p>\n

\"07Katz2ko\"<\/a><\/p>\n

Wood, not only moves, because of its environment but because of many other factors.\u00a0 Here are six distinct factors as to why wood moves.<\/p>\n

    \n
  1. Width of Material – <\/b>The wider the board, the more the movement.<\/li>\n
  2. Grain Orientation- <\/b>Flat and quarter-sawn lumber can make a big difference in telling how much your wood will expand or shrink.\u00a0 Quarter-sawn shrinks and expands roughly half as much as flat sawn.\u00a0 Flat sawn shrinks and swells less in thickness while quarter-sawn shrinks and swells less in width.<\/li>\n
  3. Moisture content of the wood at delivery – <\/b>You should know the moisture content of the decking material when you receive it.\u00a0 This is measured using a moisture meter.\u00a0 If you do not check your moisture meter upon your woods\u2019 arrival then you will not know if your lumber has already began to move.<\/li>\n
  4. Humidity inside and outside the structu<\/b>re.<\/b>\n
      \n
    1. Homes in the US that lack humidity control, typically experience levels of humidity from 25 – 65% relative humidity.\u00a0 This will cause a 6% change in the MC of the wood.\u00a0 This means if you have a 12 inch wide board it will shrink or expand by a \u00bc inch.<\/li>\n
    2. Exterior humidity is different.\u00a0 Most of North America experiences humidity levels ranging from 60-70% in the summer and winter.\u00a0 If your material is delivered at 6-8% MC then it will experience more than a 2% change in size as it gets used to the EMC.<\/li>\n
    3. Species affects the amount of movement <\/b>– <\/b>Most species of flat grain will change 1% for every 4% change in MC.\u00a0 The movement values for quarter sawn lumber are approximately \u00bd the flat sawn values.<\/li>\n
    4. Applied finish won\u2019t stop size change-<\/b> It will not stop the size change but it can slow the rate of moisture exchange down.\u00a0 Finished wood will eventually accumulate to EMC levels.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n

      Environment and wood species are the main reason as to why wood moves.\u00a0 When buying your lumber make sure to check your supplier\u2019s environment and to calculate how much your wood will shift in size.\u00a0 If you want to play it safe, it’s best to buy your wood at least 3-4 days prior to starting your project, so you can let it get acclimated.<\/p>\n

      Get your free Ipe decking quote directly from the mill. Contact IpeDepot.com today.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

      Why Wood Moves Like many building materials, wood expands and shrinks. This is due to how much moisture is in the air.\u00a0 If there\u2019s high humidity the cells within the wood will expand.\u00a0 If there is low humidity, the cells … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,37],"tags":[],"class_list":["post-112","post","type-post","status-publish","format-standard","hentry","category-features","category-ipe-decking-benefits"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/posts\/112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/comments?post=112"}],"version-history":[{"count":19,"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/posts\/112\/revisions"}],"predecessor-version":[{"id":306,"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/posts\/112\/revisions\/306"}],"wp:attachment":[{"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/media?parent=112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/categories?post=112"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ipedepot.com\/deckblog\/wp-json\/wp\/v2\/tags?post=112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}