Trimming down pressure treated 2x4's 1

[Beggar]

For a project at home I'm considering trimming down some PT 2x4's to be 1.5 square. My concern surrounds potential reduction in protection of the wood.

Does pressure treating go through the full depth?

My application is sinking some boards through a french drain to be embedded in concrete underneath the drain. My intention is to wrap the wood in plastic as a vapor barrier and then extend the concrete up above the level of the drain so that the wood should never "see" actual earth or prolong water contact.

I'm investing a bunch of labor into this and don't want to be digging these boards up again in 5 years due to rot.

 

[CSEllc]

The PT should extend thru the full depth of the 2x4.

I don't understand what you plan on doing, but it sound a little strange to me.

Why not buy PT 2x2 ballusters instead of ripping 2x4's to 1.5 square?

 

[Beggar]

The only reason to buy the 2x4 and rip it is that the only 'local' places are box stores that don't seem to carry anything PT except 2x4/6/8 etc, 6x6 & 4x4.

I'm not familiar with the term balluster. I take it that's something that I'd be likely to find in the 2x2 config?

I'll call around and ask.

Thanks.

 

[boo1]

CSEllc has an excellent idea of the 2x2's. Baluster is the term for the spindle of a stair rail system.

I would caution ripping PT. The penetration depends on species and treatment used. See:

http://www.fpl.fs.fed.us/documnts/FPLGTR/fplgtr113/Ch14.pdf

 

[crossframe]

Sometimes the box stores call them "pickets." They're usually in the same aisle as the wood decking materials.

 

[AlohaBob]

Handling PT lumber is not good. You could also use a species that is more decay resistant. Cedar or Redwood have this quality.

 

[bylar]

We do this all the time but we use 2x12 stock and rip it down for pickets. Its cheaper and we like the square edges not the rounded edges.

 

[MouseTrap]

Beggar,

You still haven't answered CSEllc's statement implying that we don't know WHY you are doing this - not exactly sure what you are trying to do.

There are now also plastic decking materials that are available which are basically a mix of polypropylene and wood fiber. Seems this stuff has the potential (in a non-weight bearing situation) to last longer than PT, and can probably be worked with typical woodworking machinery.

Mousetrap

 

[DTGT2002]

I would suggest Trex or one of the other "wood" like poly mix members.

Unless you specifiy a suitable level of treatment i.e. special order, the PT lumber you buy at our big friendly box stores is not typically intended for continous exposuse to earth or water. Even with your vapor barrier, I would expect water to be trapped against the wood once the wood is cast and buried. Additionally, this may not meet code in your area.

Check into Mousetrap's suggestion on wood alternatives.

Good luck,

Daniel

 

[amorrison]

Consideration - - when you rip the 2x4's down to 1.5x1.5 (with your skill or table saw ?)the chemical fumes coming of may not be pleasent - sort or long term! Cough Cough.

 

[RARWOOD]

If you rip 2x4's down to 2x2's you will not have the same decay resistance as you would with properly treated 2x2's. The treating standards are based on the concentration of treating chemical to a certain depth of the member. The standards do not require full penetration of the treatment.

A few species such as Southern Pine readily absorb the treating chemical and may achieve full penetration. However the presence of heart wood and other factors can inhibit full penetration.

Also one of the most important thing is that the wood you are using contains a tag or stamp indicating that it was treated to the proper standard for your application. I have seen some treated wood with no stamps which appear to have been treated to the dip standard, dip it in treating solution and call it good.