Laminating 2x6s for pole buildings

[SuperCobra]

Thinking about laminating 2x6s for a pole run-in shed. Would seem to be cheaper than buying 6x6s, straighter, and a wider range of lengths.

So what do people use to hold them together? I have a nail gun so would rather use that and construction adhesive (if needed).

Assuming codes don't apply, what have you seen used? I'd rather not spend a lot of money in hardware (carriage bolts, lags, etc.) if I don't have to but I don't want it delaminating a fews years from now.

In other words, is the newer pressure treated wood really as corrosive as the inspectors would lead you to believe?

 

[Duffster]

Nails and glue. You do need hot dipped or stainless.

 

[carpenter383]

Thinking about laminating 2x6s for a pole run-in shed. Would seem to be cheaper than buying 6x6s, straighter, and a wider range of lengths.

So what do people use to hold them together? I have a nail gun so would rather use that and construction adhesive (if needed).

Assuming codes don't apply, what have you seen used? I'd rather not spend a lot of money in hardware (carriage bolts, lags, etc.) if I don't have to but I don't want it delaminating a fews years from now.

In other words, is the newer pressure treated wood really as corrosive as the inspectors would lead you to believe?

I have seen this on multiple pole buildings and we just recently built one using this method. You need to use double treated 2x6's in the ground. The standard treating is not meant for underground use. Anything above ground (and out of the weather) obviously does not need to be treated. Laminating posts is a good way to avoid twisting and warping of a typical post. We just nailed the 2x6's togeather without any glue, but using glue would be a good idea and couldn't hurt anything. Just keep each 2x6 staggered from the next one a couple feet and you should be fine.
This also makes it easier to build headers into the posts because you can cut each 2x6 to the specific length you need by subtracting 11-1/4" on the outsides for a 2x12 header over a garage door or 5-1/2 for a 2x6 over a window etc.

 

[SuperCobra]

Thanks. I take it I won't find "double-treated" boards in the deck section of Home Depot or Lowes. I've heard of rating like .60 something and .40 something or lables like "burial' or "direct ground contact."

 

[MikeInEburg]

Yes, "direct ground contact" is what you want. I made the same decision recently and ended up just using 6X6 posts - found it easier than trying to laminate my own.

Mike

 

[Kays Supply]

On my pole barn they left the center 2x6 short and put the truss in the pocket. They then cut the outer 2x6s flush with the truss. It made a really neat and strong setup.

 

[EddieWalker]

I don't know what research has gone into this, but I have my doubts about using 2x6's instead of 6x6's.

First, I've found that the larger the PT wood, the straighter it tends to be. PT 2x6's are hit or miss on whether they will stay straight, or twist on you. When I buy them, I buy extras because I know a few of them will do something on me. Even after picking through the pile and getting the straight ones, some will still do what they are going to do.

Second, I think that the solid piece of 6x6 tha is notched is much stronger then three 2x6's. I don't know how true this is, and it could easily by to a degree that both are plenty strong enough with an insignificant difference. If you need to support ten thousand pounds, and one will hold 20 thousand and the other will hold 25,000 pounds, then it doesn't make any difference.

Third, I know that posts are treated to a higher degree, or percentage, to be set in the ground. Off the top of my head, there are three basic ratings for pressure treated wood. Outdoor use, like decking is the lowest rating. The next is dirt contact, such as a post set in the ground. The highest rating and treatment is for posts in water. I've never seen a PT 2x6 that was rated for ground contact. On the labels, it will say what percentage of treatment the wood has. Look at the 6x6 and compare it to the 2x6.

I realize that it's becoming fairly common for barn building companies to use 2x6's for thier posts. I would like to hope that they are using them with the rating for dirt contact, but I don't know this for sure. I think the big advantage to using 2x6's is that it's faster to notch the posts. In fact, you don't notch them at all, you just cut the board to length and then attach it again with the space for the notch. When time is money, that's what you get most of the time.

Eddie

 

[JDeerekid]

You can always use this product Perma-Column | Permanent Foundation Systems.

This is what I used for my pole barn. Cost a little more but will never have to replace due to rotting.

 

[QRTRHRS]

Glued and splined 2x6's etc. have been available for years with the end meant for the ground being treated. Prior to ACQ treated lumber, .40 retention was for surface contact only if that and .60 on up for inground. I have not kept up with the ACQ aspect other than it eats fasteners so use really high quality. I also do not think that ACQ uses the same rating system.

A few years back, I delivered pole barn material for a large builder that also had a Perma Column franchise. For there own use or customer demands (the customer could purchase only the Perma Columns) they would simply air nail 2x.. non treated stock together with no glue. This method was advised by Perma Column from what I know.

I think you could laminate your own posts using varying lengths of treated. Don't forget to put some blocks on the lower part for uplift resistance. Pre drill the treated especially on the uplift blocks to minimize cracks. An email to the fastener manufacturer about the below ground application would be beneficial. The truss pocket is a good suggestion.

 

[mcd176]

Eddie,

Just FYI, Morton buildings use the laminated 2x6 method on all of the pole buildings around here, My office just had Morton build a 50x100x14 building and thats how they did it.