Some TREATED LUMBER Rots Faster Than Others! WHAT'S THE DIFFERENCE?! (Ground Contact Vs. Non-GC!)

Check Out Our FREE GUIDE: 25 Must-Have Carpentry Tools...Under $25 Each!
https://www.thehonestcarpenter.com/

Did you know that there are multiple varieties of TREATED LUMBER? And that some treated lumber will rot much faster in certain conditions? This short video from The Honest Carpenter explains the various treated lumber USE CATEGORIES!

Check Out Our Other Lumber Videos:
Is Treated Lumber Toxic?:

Is Particle Board The Worst?:
The Truth About PARTICLE BOARD...Is I...

Treated lumber and wood doesn't last nearly as long as it used to. This is because we shifted our pressure treatment process in 2009.

For years, Chromated Copper Arsenate was used to treat the vast majority of lumber in USA. But CCA contains a trace amount of arsenic, which caused concern. So, the EPA encouraged companies to switch it out for two other treatment fluids:

Alkaline Copper Quaternary (ACQ)
Micronized Copper Azole (MCA)

These fluids don't protect lumber quite as well, and they also contain a higher concentration of COPPER, which makes them expensive to use.

In order to avoid very high lumber prices, lumber companies began grading treated lumber and treated wood based on how much treatment chemical was present in various grades of lumber after drying out. This quantity is known as TREATMENT RETENTION.

These retention quantities fall into USE CATEGORIES, since different retentions are suitable for various ideal uses.

Use Categories fall on a scale of 1A to 5C.

Lumbers up to the UC3C range are considered ABOVE GROUND USE, or NON-GROUND CONTACT lumbers, because they can't stand up to the high moisture saturation levels in various soil substrates.

However, lumbers graded UC 4A or higher are GROUND CONTACT lumbers, since their retention levels can handle contact with or immersion in the ground...or even directly in water!

These lumbers are used for deck posts, fence posts, structural exterior members, foundation piers, and more...

To find out more about the various Use Categories, check out some of these websites, which have great, detailed information!:

https://www.decks-docks.com/treated-l...
https://plasticinehouse.com/pressure-...
https://wooditsreal.com/2017/05/02/wh...

Thanks for watching!
The Honest Carpenter