Post for workshop.....Solid vs Glulam

[jmc]

The other advantage claimed for laminated beams like Morton's is that the chemical won't fully penetrate a thick board so the inside rots out eventually. OTOH, each 2 x ? will be fully penetrated so laminating any quantity of them has full protection.

Also, I like the way Morton leaves the middle board of a three board post a little short at the top. This allows the rafter to be sandwiched by the two other boards as well a sitting solidly on the middle board end grain. With a conventional post, it's attached to the post's side.

 

[Rock knocker]

The other advantage claimed for laminated beams like Morton's is that the chemical won't fully penetrate a thick board so the inside rots out eventually. OTOH, each 2 x ? will be fully penetrated so laminating any quantity of them has full protection.

Probably not. Most treated GLB's are first laminated, then treated as a whole. It is true the treated wood can rot from the inside, but only if the bugs can get there. That is why it is crucial that ends and notches be treated. But they are more often than not, not treated.

 

[jmc]

I wasn't implying that Morton's beams are GLB. But they ARE laminated.

 

[Rock knocker]

If they aren't a glue-lam beam (GLB) what are they then? A LVL? LSL? Those are not usually used in a vertical application

 

[LD1]

If they aren't a glue-lam beam (GLB) what are they then? A LVL? LSL? Those are not usually used in a vertical application

If you are refering to what morton uses, they are neither. They simply sandwich 3 2x6's or 2x8's together with nails. They may use glue???? But I dont think they do.

Here, read up Features Three-Member Laminated Columns by Morton Buildings, Inc.

 

[KennyG]

Based on the original post, I would stay with the glue-lam. When you start to get over a certain height, the post compressive strength no longer controls the design. Bending and buckling become the critical loading. The reliability of the bending strength of the timber post is relatively low because of the inconsistency of the grain. The glue-lam will be much superior.

 

[Kenfyoozed]

Thanks for all the help. I just wanted to update with my findings. I did indeed speak with the engineer and he reran the numbers of the ABMartin post. He concluded that the ABMartin post would meet the the specs for my shop. So thanks again. This will be my first building project. I will have others, family and friends, guide me along the way. Im sure i will have plenty more questions, so bear with me if you dont mind.

 

[dirtbone]

8X8 southern yellow pine PT. 7 1/2/ by 7 1/2 actually. They are strong as ****! I can't believe your engineer didn't have enough practical in him to spec those, given cost, convience, etc.

 

[jimgerken]

After using both solid PT posts and laminated 2x6 assemblies, I would use the laminated if possible. PT penetration is one reason. A big solid post is nice if kept dry, but in reality if it is in the ground it is soaking wet for the rest of its life. In my experience a solid post will last about 40 years at ground level. Sometimes more, sometimes less, depending on the species and the ground conditions and the side of the building it is used on (north,south, east...). A step up from laminated is to put the laminated in bracketry on top of a thickened edge slab, however I would not build 20 feet tall with that method, assuming a standard pole building with no sheathing either inside or out.

 

[marcomjl]

I am a builder and the code book as per-engineered charts for different types of lumber and sizes and that 4ply glulam is a type of fir most likely. Fir, whether hem or douglas is much stronger than pines, spruces, etc so just from that, pine will definitely not do. Just go with the glulam or LVL, glulam will be cheaper most likely.