New Post Frame Building Questions

[Duffster]

My shed they used 9 foot spacing on the poles, 81 foot building. 10 foot seems too much for any type of snow load, don't hear of that. 8 or 9 is normal.



--->Paul

Truss spacing has nothing to do with snowload.

Many buildings around here have 12' spacings and I have seen several with 16' spacings.

 

[rambler]

I'm assuming a wood pole shed with metal skin. It becomes combersome to make more than a 9 foot spacing for the girts & perlins to hold up more than a 9 foot spacing under typical northern wind & snowloads. Anything is possible, but if ecconomy is part of the equasion, it rarely makes sense to do more than a 9 foot spacing.

If this is a metal frame then greater spacings can work ecconomically - but typically only for larger buildings to start with. However for the size, I'd price out a wood building to compare.

Whatever is wanted can be built, of couse. I'm not paying for it, so doesn't bother me.

--->Paul

 

[Duffster]

I'm assuming a wood pole shed with metal skin. It becomes combersome to make more than a 9 foot spacing for the girts & perlins to hold up more than a 9 foot spacing under typical northern wind & snowloads. Anything is possible, but if ecconomy is part of the equasion, it rarely makes sense to do more than a 9 foot spacing.

I was thinking economy was why they went with 12' spacing.

 

[rambler]

I was thinking economy was why they went with 12' spacing.

I'm thinking wood pole, I'm way wrong if we get into metal frame:

If you build a stud wall on 16 or 24 inch centers, or a pole building on 6, 7, 8, or 9 foot spacing, you end up needing about the same amount of vertical wood. Space out a 6x6 or 8x6 pole over the distance covered, and - you will see it always equals almost the same amount of wood.

It takes a lot less labor to place posts every 9 feet, rather than a stud every 16 inches. So, the pole building can be built cheaper. But it doesn't use _much_ less materials - it just groups them into units that need less labor.

The problem is wind load, or snow load. As the distance bewteen the poles increases, the horizontal boards need to get bigger to resist bending & breaking. This increases the cost rapidly - once you get past 8-9 feet.

Anyhow, that is my layman's understanding of it. I've been known to be wrong before.

If you don't need to plan for snowload then you can get by with smaller wood and perhaps extend the spacings ecconomically. But in a snowload area, you need to use real fat wood real fast as you icrease the spacings.

The roof of the lumberyard building 3 towns over collapsed last week, we've had heavy wet snow with a bit of rain, now it is minus 30 for a low last night.... A tough winter again, we have several months before anything will melt, good chance for more to pile on. It must be embarassing for the lumber yard to cave in. Iorny. A 5 foot drift piled on the roof, they were trying to remove it, all were off the roof at the time, and the one employee inside heard the cracking & got out the door as it collapsed.

--->Paul

 

[Duffster]

I'm thinking wood pole, I'm way wrong if we get into metal frame:

If you build a stud wall on 16 or 24 inch centers, or a pole building on 6, 7, 8, or 9 foot spacing, you end up needing about the same amount of vertical wood. Space out a 6x6 or 8x6 pole over the distance covered, and - you will see it always equals almost the same amount of wood.

It takes a lot less labor to place posts every 9 feet, rather than a stud every 16 inches. So, the pole building can be built cheaper. But it doesn't use _much_ less materials - it just groups them into units that need less labor.

The problem is wind load, or snow load. As the distance bewteen the poles increases, the horizontal boards need to get bigger to resist bending & breaking. This increases the cost rapidly - once you get past 8-9 feet.

Anyhow, that is my layman's understanding of it. I've been known to be wrong before.

If you don't need to plan for snowload then you can get by with smaller wood and perhaps extend the spacings ecconomically. But in a snowload area, you need to use real fat wood real fast as you icrease the spacings.

The roof of the lumberyard building 3 towns over collapsed last week, we've had heavy wet snow with a bit of rain, now it is minus 30 for a low last night.... A tough winter again, we have several months before anything will melt, good chance for more to pile on. It must be embarassing for the lumber yard to cave in. Iorny. A 5 foot drift piled on the roof, they were trying to remove it, all were off the roof at the time, and the one employee inside heard the cracking & got out the door as it collapsed.

--->Paul

Do you have 2 x 4 purlins with your 9' spacing?

 

[rambler]

Do you have 2 x 4 purlins with your 9' spacing?

Yes. On edge. Placed between the trusses.

The girts are bigger - I think 2x8, but could be 2x6 - I should measure that. They are flat on the building, outside of the poles. It's 24 below zero, was up to 12 below this afternoon - I might not go measure it right now!

--->Paul

 

[wedge40]

It's 24 below zero, was up to 12 below this afternoon - I might not go measure it right now!

--->Paul

Maybe Al Gore will pay your heating bill, since we are having such a problem with global warming this has to be a fluke.
I woke to -1. We get that kind of temps here, but usually not till the middle or end of January. Hmm maybe spring will earlier this year.

Wedge

 

[RWTschoeke]

I had considered placing a door on one of the sidewalls but decided against it when I saw the huge snowpiles from roof slide in front of the side doors every spring. Around here those snowpiles may hang around into May. I hope to be getting the toys out earlier in the year. Plus making a 90 degree turn inside the building will cut down on usable storage especially if you have a long trailer attached. The sliding wider door is a good thought, but 14' should be plenty for my needs; heck you could fit a friggin semi in this building.
Parking may be a challenge but being able to approach from both sides makes backing in easier. In the winter, I will most likely store in front of one of the doors leaving the other free to get the tractor/snow plow out. I have a trailer dolly that allows one to move trailers around in tighter spaces without the need of a car/truck.
There will be no support poles inside the building; at least until I decide to put in the mezzanine which will then require additional support.
Regarding the trusses: Snow load is determined by the extent of bracing within the trusses, truss width and wood type.. For my purposes (48' wide building w/ trusses 8' OC, the cost of going from 30 to 40 psf was much greater than 15 to 30 psf snow load. I'm sure each situation is unique and the engineer designing the trusses is one you must have confidence in.

 

[RWTschoeke]

The building is nearly completed and I've taken some pictures which I would like to post to this forum. Could someone please explain the easiest way to post pictures to this forum with descriptions from an IMac? Would like to get them downloaded and show the fine work the builders have done.

 

[mojoinco]

Just a maybe-too-late thought. There are foam rubber pieces that fit on either side of the metal siding at the top and bottoms of the panels. A lot of folks aren't aware they exist. Adding them in during construction (about the only time to do it). Keeps the wind, rain, snow drifts, and maybe some of the mice out of it. I think you use only one of the inner or outer pieces as the situation warrants. I had to engineer a solution to a problem I have with snow blowing into my shop (mostly the prevailing storm wind side) as my shop had none of this. I cut pieces of pipe insulating foam with angled ends and stuffed them into the groove at the tops of the walls. It has worked well, and I did the same thing for my wife's horse barn. It would have been nicer to have it built with the foam. And I think the foam pieces built in would have made the shop a lot more air tight.

When you lay your floor out, leave a few 'pockets' around the edges for entrance and exit points (water, power, air, gas, etc). Back fill them with gravel. This will mean no need to cut the wall for penetration points later. Except for the inevitable change in plans.

I have a cut (stress/crack line), smooth finish floor. Sooo much nicer than the brush finished and molded pad outside the door. I can roll a creeper (or anything else) on the interior floor. You could just cut the floor on the work bench area to save some money, and mold the rest.