Additional Installation Instructions
Know your Wood and your Environment
For all this to work and work well, there are a few things you need to know before you start.
#1—Your wood specie and it’s reactivity during changes in the environment.
There are a lot of specie choices out there in the hardwood decking market and most of them are good. Ipe, Cumaru, Massandubra and the Garapa are the most common. All of these are good choices and they will per-form well if you know what the moisture content of your wood is and if you take your local environment into consideration when you install the product. All wood moves with moisture changes and it starts the day you install your deck, so you have to allow for this throughout your project.
#2—Is it green, air dried or kiln dried?
First thing you need to know is the moisture content of your decking. Ask your supplier if it is air dried or kiln dried. It is unlikely that it is green because it probably came over on a boat from somewhere and at least was out on the deck on drying sticks. This may be sold as air dried and the moisture content can vary widely! Air dried lumber can be anywhere from 15% to 45% moisture. There are no real standards. If your decking is air dried ask your supplier if they know what the moisture content is. Hopefully they can give you an idea. Most air dried decking is about 15% to 20% moisture. If it has been kiln dried it should be about 10% to 12% moisture for outside use. The reason you need to know this is so you can choose the correct spacing for your decking.
#3—Now that you know the moisture content you can choose your spacing.
If your decking is air dried and the moisture content is above 20% you can just set the boards as close as the deck clips will allow, about 1/8 of an inch. If they do anything they will shrink a little bit and you will be fine. There will be enough room for the boards to move a little during normal seasonal changes in the moisture content of the wood. If your wood is kiln dried or it is below 12% moisture we recommend you space the board about 3/16 of an inch. Your boards may shrink a little but they may also grow a little during wetter periods. If your wood is very dry, 8 to 12% and you get periods of wet weather or wet snow you may have to space your boards as much as 1/4 inch apart. Cut a few scraps of wood at the spacing you need and use them as spacers for about 2 or 3 runs and move forward as you go.
#4—Last but not least—the variations in the species and your local environment.
Of the above woods, Ipe is the most stable followed closely by Cumaru. Massandubra will move the most in changes in moisture content but that does not mean it won’t work well you just have to allow for the slight in- crease in movement. If you are installing Massandubra in a very dry climate and the wood is very dry but you get periods of wet humid weather, you may want to install it with at least 1/4 inch of gap.
This information is provided as a guide only. For best results ask your lumber provider for explicit information about the particular specie you are purchasing