Simple Outdoor Project Gets Complicated

In my mind, some of the projects that I want to do are just simple little weekend projects.  I'll gather up a few tools and pick up a bit of lumber and make a few sketches.  Then, as I start to make my list, and I love list, I find that I have a lot of questions about what I should buy and how things should go together and before I know it, I am making a list of the people that I will probably need to get advice from, if not to have assist in my project.

This all holds true for two of the three projects that are on my "get done quick, before Winter !" list.  As I find some interesting information I will pass it all.  The most interesting info that I am finding is about treated lumber.  Sounds simple - right? - it is treated so it will hold up to weather and resist rot, even without coating with a sealant, and the bugs don't really care for it much. Still sound pretty good.  But what is this on the label?  The actual name of the lumber is 'Pressure Treated Hemlock Fir Brown Lumber'. Catch that part that says "Hemlock"?  Yuck!  I guess that is why the bugs don't like it.  Or don't live after they chew it?  Creepy!   I also saw in the cutting and sanding instructions that you need to be extremely cautious when working with it so you do not inhale the cuttings or the possible fumes that may come from the boards.

I am going back to my list.  I will still purchase the treated wood but - sorry Bro - I will definitely need a lot of help with my not so small projects.

I've gotten a bit of an education about Hemlock treated, bug killing wood, and a little of it I would like to share with you now.  Hope you find it a bit interesting or helpful. 

Tip 1: Buy pressure-treated lumber with the right amount of treatment for the job

 

Treatment levels for different uses

“ABOVE GRADE”
.15 TO .25 LBS./CU. FT. 

“GROUND CONTACT”
.40 LBS./CU. FT. 

“BELOW GRADE”
.60 LBS./CU FT. 

Wood used in situations where it's more likely to rot contains more preservative.

Pressure-treated lumber is the logical choice for the structural part of your deck—the posts, joists, beams and other members you normally don't see. Pressure-treated lumber can support more weight and span longer distances than cedar, redwood or other woods commonly used for building decks. It's also much less expensive. 

Pressure-treated lumber is rated according to the pounds of preservative retained per cubic foot of wood; the higher the number, the better the protection against fungi and insect attack. Select boards with the preservative concentration suitable for their use.

 

The three common ratings:

1. Above-ground use (.25, sometimes .15). Typically used for decking, fence and railing material.
2. Ground-contact use (.40). Typically used for posts, beams, joists and, again, decking. 
3. Below-grade (.60). Typically used for support posts that are partially buried below grade and for permanent wood foundations and planters.

Your boards will be tagged with the concentration and treating solution used. Use .40 material if you can't find .25. CCA (chromated copper arsenate) is being phased out because of health concerns. ACQ (Alkaline Copper Quat) and other preservatives are replacing it. 

Tip 2: Avoid treated lumber that has a lot of heartwood

About 70 percent of this post is heartwood, which did not accept the preservative treatment.

Since heartwood—wood from the center of the tree—is denser, it accepts pressure treatment less readily than sapwood—wood cut from the outer edges. This isn't as great an issue with dimensional lumber like 2x10s and deck boards; these boards are thin enough that the preservatives are usually driven throughout. But with 4x4 and 6x6 posts, the preservatives may not penetrate the dense heartwood. However, it can be difficult to find posts not cut from heartwood.

So there you have a couple of facts about pressure treated wood that I find most helpful. Stayed tuned for an update when the project gets started.  They are not big, in my mind, but may be worth sharing.