The 5/4 vs 4/4 Decking Debate

I am frequently asked if 5/4 is better than 4/4 for Brazilian Hardwood Decking

 

There are two thoughts on 5/4 vs. 4/4 decking boards and it seems to depend upon where you live.  It is almost like a cultural influence.  For example, if you live in South Carolina 5/4 seems to be the standard.  In the Georgia - Florida area 4/4 is what people want.   When I started asking for reasons, no one seemed to have any as to why they used 5/4 vs. 4/4 or vice versa.  Everyone had their opinions but no one had anything definitive.

 

To best answer everyone, I can share my personal experience with Cumaru.  I did similar research as you are doing as I built my dock prior to selling Brazilian wood.  (Actually, I loved the product and that is how I got involved with selling decking).    I found very few people sold Cumaru, Jatoba, and Tigerwood.  Most retailers sell Ipé as their only choice in Brazilian decking.   Ipé is a very colorful wood but liked the soft brown hues of Cumaru.   After deciding upon my decking wood, then the choice was 4/4 vs. 5/4.  I found that some people swore by 5/4 and others swore by 4/4.  I finally let the hardness of the wood decide for me.  The Janka scale of hardness tells you how hard wood is.  It is complex for me so I just used the scale to compare woods that I knew to the Cumaru.    http://bwdepot.com/Pages%20Document/janka.htm   That showed me that Cumaru is several times harder than Oak or Hickory.  I know that Oak and Hickory are very hard and decided that with so much 4/4 sold it must be fine for my application.  From there I used 4/4 x6 for my dock with 16" centers for the joists.   The outcome is my dock is solid, just like walking on the ground.    I am very pleased with the result.

 

I know that is a long answer to a short question.   But the real answer seems to be personal preference and cost.  Because of my experience I only sell the 4/4 because I feel the 5/4 is overkill and a waste of money.  It is also not as environmental friendly as you can make more 4/4 boards than 5/4 from a tree.  Now if you decide upon Ipé, it is even harder than the Cumaru.   So the answer of 4/4 over the 5/4 becomes even more valid.  To summarize, 4/4 Brazilian Hardwood Decking is ample for most if not all applications.