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Southern yellow pine

Started by BigZ La, August 31, 2016, 09:52:45 PM

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BigZ La

If I were to buy air dried southern yellow pine to use for floor joists and have them treated with cca treatment would I need to have them kiln dried?? Thanks for any info.

Den Socling

I'm no expert on air drying SYP but more information is probably needed. Where is the location and how long is the SYP air dried? My educated guess is that you can.

BigZ La

The pine is in South Louisiana and has been cut for a few months. I can let it dry as long as needed to get to the proper moisture level, I'm really just wondering if after it's air dried does it need to be kiln dried if i'm going to treat it with cca. Thanks again.

GeneWengert-WoodDoc

AD is the correct MC for treating.

After treating, it would not be unusual to see the MC over 75% MC, which means they are very heavy.  As they dry in place to their final MC, they will shrink in width and thickness4%, which means a 2x10 that is 1.5 x 9.25 when planed after air drying will shrink to about a final size of 1.42 x 9.0.  This can be important, but even more of an issue is that the SYP is prone to warping during drying to a lower MC, so a few pieces might warp after installation (twist especially) and this can be a real problem.

Note that you always need to place to sixes prior to treating as you do not want treated planer shavings.  Plus, after planing, the amounts of treatment left in the lumber is less.

The more common practive for non-ground contact joists that are kept fairly dry in use is to spray them is a decay resistant coating.  This is quite popular and provides reasonable resistance, but not perfect.  Ask any builder how they do it in your area.

Because the pieces are fairly dry in most uses, this spray needs only to protect against termites and not decay.  The common termite prevention method is also to use bait stations to monitor any activity rather than spray the soil initially.  Your county extension office will likely have specifics on all this for your county.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Magicman

I am wondering why they need to be "treated" or kiln dried?  Any shrinkage will be uniform across all of the joists and negligible.  A termite shield on the foundation will prevent termite infestation.  LINK

   
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

BigZ La

Thanks for all the help. My present house if built off the ground and I have recently had a mold problem which caused my joists and sub floors to rot out. I have replaced most in my house about 3 years ago but now I have to do my kitchen. It has gone bad recently. The only thing that stops mold and protects against termites for the long haul is CCA treatment. For my house I will buy commercial lumber to repair shortly.

What I'm asking for is in the near future I will be building a camp near a lake and want to prevent this from happening. I have had a guy do some sawing for me in the past and I can get pine from him at a reasonable price, have it treated and still come out cheaper then buying it retail. I will purchase it from him after being air dried and take to the treater, after treatment will bring home sticker and probably bind to prevent as much warpage as possible. When I have a project like this I like to plan ahead and get most everything ahead of time so when I start I can go from start to black in rather quickly. Joists will not be sized or planed after treatment. If needed I will just shim or remove as needed to level. I usually let it go if it's within a quarter inch  :D

Magicman

You may need to treat the problem rather than the symptoms.  A good moisture barrier LINK on the ground and plenty of foundation vents
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

BigZ La

Believe me if I could I would. Other than knocking out my block wall foundation I have tried most everything including a fan to circulate more air for drying. The problem is I live near the Mississippi river and when it comes up for prolonged periods of time the water table comes up to basically ground level and no matter what you do you get moisture under the house. I could pour concrete all under there which is what I would do if I ever were to build again for a home but CCA treatment solves that problem completely. That's why I'm wanting to do this with the camp.

Magicman

Actually, I am with you and suspected that the water table was your problem.  That is why so many of the older houses were built "plantation style" up off of the ground to allow for air circulation. 
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

GeneWengert-WoodDoc

Mold does not cause rot.  Rot or decay fu go need lots of water.  Do you have he ground space under the house cover with a plastic sheet and also vented?  The risk of decay is minimal under 25% MC which is 95% RH.  So. It is obvious that you have conditions under the house more humid on the average than the outside humidity.  So, treat the problem, as mentioned.  Good luck.  Your county extension office can help.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

ozarkgem

I thought CCA treatment was outlawed.
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

GeneWengert-WoodDoc

CCA is still available for certain items.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

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