Post frame building posts idea

[STx]

Soon (like in the next 2 - 3 months) we'll be starting construction of a 50 x 60 post frame building on our property. I've been doing a lot of research on the columns and it's left my head kind of swimming. I see laminated columns with the bottom portion treated and the top regular, milled columns fully treated, permacolumns, etc. To me, it seems like the permacolumns are probably the longest lasting but they're expensive and there's no dealer for them in my area so, I've come up with something that I think would work well.

My thought is to use a 10" sonatube for each column, pour concrete and install one of these in the top -http://www.dhcsupplies.com/store/p/2401-CBSQ66-SDS2-Standoff-Column-Base.html - and then install a non-treated, laminated column into that. I think the layout to keep the columns square is going to be a real hassle but if I take some time with it, I think it can be done and I'll end up with a building that will pretty much last forever.

I will be pouring a concrete slab that will drop down 1.5" at the columns. I plan to bookshelf the walls so this drop will let me take my metal down far enough to prevent rain and wind from coming in underneath.

Has anyone else done this? Any helpful hints you can offer with the layout to keep everything plumb and square? Any reason this is a bad idea?

I appreciate any feedback, good or bad.

 

[roadhunter]

We did similar on a building at the company I work for. What we wound was the structure lacked stability and had to add additional diagonal bracing. The wood timbers in the ground keep the pole from moving. When they just sit on top of concrete they are not nearly as stable.

Steel buildings have similar issues which is why you see the cable x bracing used.

 

[STx]

That makes sense when you say it. I guess the best thing would be a laminated post that is PT on the bottom and not up top. If I'm setting them 4' deep, how far should the PT go? 5'? 6'?

 

[Sawyer Rob]

That makes sense when you say it. I guess the best thing would be a laminated post that is PT on the bottom and not up top. If I'm setting them 4' deep, how far should the PT go? 5'? 6'?

Just MAKE SURE the PT is rated to .60 or better... .40 is NOT rated for in ground use...

SR

 

[EddieWalker]

We did similar on a building at the company I work for. What we wound was the structure lacked stability and had to add additional diagonal bracing. The wood timbers in the ground keep the pole from moving. When they just sit on top of concrete they are not nearly as stable.

Steel buildings have similar issues which is why you see the cable x bracing used.

Exactly Right!!!

As for laminating over posts, the only advantage is that you don't have to notch the posts if you use the boards and cut them to length. Strength wise, if the laminated boards are glued together, they will be as strong or stronger. If not, then the solid post is going to be stronger. The strength in laminating is in the glue bonding the different boards together.

For me, I only use treated 6x6's.

Eddie

 

[PA hayseed]

In my area there are a ton of guys who do nothing but build pole buildings. All of them have basically the same specs for the buildings they do, but most of them have moved to 4x6 PT timbers (cheaper). I don't have a clue what your frost line is in TX, but if you set your poles the PT pole has to be another 6-8" (no idea how thick your pouring the slab) higher than grade to allow for gravel and concrete so that the PT part is above the concrete when finished.

On a side note, I was at an emergency training site and they had their columns completely made of concrete. Think of about 2' sonotube about 10' high. it had an arched metal roof with steel trusses and a concrete slab. Looked nice. I have no idea if it takes any abuse other than weather. I don't want to even calculate how much concrete and rebar went into that structure.

 

[STx]

In my area there are a ton of guys who do nothing but build pole buildings. All of them have basically the same specs for the buildings they do, but most of them have moved to 4x6 PT timbers (cheaper). I don't have a clue what your frost line is in TX, but if you set your poles the PT pole has to be another 6-8" (no idea how thick your pouring the slab) higher than grade to allow for gravel and concrete so that the PT part is above the concrete when finished.

On a side note, I was at an emergency training site and they had their columns completely made of concrete. Think of about 2' sonotube about 10' high. it had an arched metal roof with steel trusses and a concrete slab. Looked nice. I have no idea if it takes any abuse other than weather. I don't want to even calculate how much concrete and rebar went into that structure.

Our frost line is about 12" above grade. Seriously, frost and snow are non-issues. It will occasionally get below freezing, sometimes even for 16 consecutive hours (like once every 20 years or so) but that's about it. Our issue is windstorms (hurricanes) but they don't come around that often and we're about 70 miles inland so they get knocked down substantially before they get to us. We'll probably engineer for 100MPH winds but could get by with 75MPH if we had to. The real problem is more flying debris (tree limbs, etc.) banging into the building.

I'm planning a 5" thick, 4000 PSI slab with wire mesh reinforcement. I'm going to put a 10,000#, 2 post lift in and want to overbuild for that but otherwise, the load will be vehicles, a forklift and tractor so nothing really out of the ordinary.

Since we may be putting living quarters in it and my wife is very opposed to 8' ceilings, we're going to go at least 18' at the eaves, so we'll need probably 24' posts (a couple extra feet to allow for hole depth variance) which seems to be much better filled by laminated posts than sawn posts.

 

[boggen]

rain on metal roofs and metal sides = very loud, even though just sprinkling out side. you need to make sure you properly insulate.

1 family near me. put up all the frame work, then put on hard board insulation around the outside, and then put on the metal sides and metal roof. and then fill'ed in between the studs with roll'ed insulation. or was it sprayed in? don't remember. then what ever they wanted on the inside walls, primary goal is extra insulation to raise R value but also to act as a sound dampener, from rain hitting the metal outside. if memory serves. they did not put full cathedral ceiling in bedrooms. i think they made 'attic space" above bedrooms. to help reduce rain noise and/or was just for some extra storage space. and needing a place to add plumbing vents, and easier access to run some electrical for ceiling lights and fans.

=============
"paint" comes with all microsoft windows computer, mac's have similiar program. you can draw some "grid lines" to draw on. or get yourself some grid paper and some color markers / pens. and just start drawing for different layouts.

if you know rough size of something, cut it out of some spare grid paper. so you can toss it onto other grid paper and move it around. it does not have to be exact. just roughing layout of things. this will help ya figure out what you want and how ya want it.

most regular doorways are between 33" to 36", i like 48" wide myself. not for piece of plywood, but simply having to move stuff in/out of rooms.

 

[hcallaway]

6 x 6 treated with post protectors. Material is like a plastic bed liner that keeps the post from any contact in the ground. There are lag bolts with metal and rubber washers for up lift protection.

These were 60" so there was no way for the tops to not be below grade.

 

[EddieWalker]

I'm planning a 5" thick, 4000 PSI slab with wire mesh reinforcement. I'm going to put a 10,000#, 2 post lift in and want to overbuild for that but otherwise, the load will be vehicles, a forklift and tractor so nothing really out of the ordinary.

The difference between a well built and poured concrete slab and one that will fail is from the materials used and the preparation of the pad. Sadly, a lot of pads in my part of East TX fail because they just dump the dirt, spread it around, drive over it a few times and call it done. No compaction is done at all, so in a few years, there is a void between the dirt and the bottom of the slab.

The other common denominator is using wire instead of rebar. If both are done properly, which means they have to be in the middle to lower third of the pad, wire is actually better. The problem is that every contractor that I've ever seen, and there are a lot of examples on the builds done here on TBN, they walk on the wire and sometimes pretend to pull it up, but mostly just leave it on the bottom of the slab. They all say they pull it up as they go, but it is impossible to pull it up and walk on it at the same time and have it end up in the middle of the slab. It ALWAYS ends up at the bottom of the slab, either in the dirt, or on the plastic. Using wire on a slab is both a waste of money, and totally useless!!!!

Rebar is better because you put it on chairs and it's spaced wide enough that the guys spreading it can walk between it. This means it stays in the middle area of the slab and it's able to hold the concrete together. You can never stop concrete from cracking, but you can control it and keep it tight with enough rebar that is properly installed.

When concrete is mixed, the proper ratio of water will give it the most strength. Add more water, and it loses a lot of it's strength. Lazy contractors and some concrete truck drivers like to add a lot of water to the mix so it flows easier. This makes the job easier and faster for them, but you are left with what looks like a strong slab, but it cracks all over as soon as it cures.

I'm not a fan of fiber, but it doesn't hurt anything either. Getting the basics correct is what really matters, adding fiber is more like buying insurance, it makes it a little better, but it doesn't replace rebar on chairs, overcome a bad pad or too much water.

Eddie