Welcome to Ask the Pole Barn Guru – where you can ask questions about building topics, with answers posted on Mondays. With many questions to answer, please be patient to watch for yours to come up on a future Monday segment. If you want a quick answer, please be sure to answer with a “reply-able” email address.
Email all questions to: PoleBarnGuru@HansenPoleBuildings.com
DEAR POLE BARN GURU: I have built a 40x64ft pole building with 14ft sidewalls. I have sheathed the entire walls with osb and intend on doing the same with roof osb. My trusses are 8ft on center with purlins running horizontal every 2ft on center. Should my roof osb be ran vertical or horizontal on the roof? Either way I will need roof clips between panels, just concerned which method would be best?
Please respond back if you can. STRESSED OUT IN WYOMING
DEAR STRESSED: Be stressed no longer!
Structurally the sheathing can be run in either direction and is equal in shear strength either way. My instinct tells me to run it up the roof – which is how I personally would install roof osb . Unless the building is being constructed under the IRC (International Residential Code) H clips are not a requirement: https://www.hansenpolebuildings.com/blog/2014/03/roof-sheathing-clips/
Before sheathing the roof, the engineered roof truss drawings should be reviewed to ascertain if they are designed to adequately carry the added weight of the sheathing. With steel roofing, a minimum of five psf (pounds per square foot) of top chord dead load would be needed.
Mike the Pole Barn Guru
DEAR POLE BARN GURU: Can a monitor style pole building be built with no interior posts but including a loft for light storage? I have received several quotes from Mark at Hansen and am getting close. Thanks!
GREGORY IN MARION
DEAR GREGORY ~ Can it and should it may not arrive at the same answer. There are three components to any construction design solution – imagination, budget and available space. You’ve got a lock on the imagination part (always my favorite). To begin with – clearspan monitor trusses can be designed for virtually any span, including the 40 foot width you have in mind. A couple of considerations – the first impacting looks, which is to make sure the “rise” in the center is tall enough to actually provide the monitor “look”. The second – try to keep the overall truss height to 12′ or less as not all wood truss manufacturers are capable of fabricating trusses taller than 12 feet and for the ones which can, the logistics of transportation increase the challenges (as well as costs).
In your particular case – the relatively low roof snow load requirements will help to offset the added costs to design for the light storage load capacity you are considering loading. As snow loads and spans increase the investment can easily outweigh the gain.
One other consideration is will you even use the space? With the requested 14 foot tall overhead door, the bottom of the trusses will be at least 15 feet above the concrete floor. Fifteen feet may prove inconvenient for loading stuff into the storage area.
Mike the Pole Barn Guru
DEAR POLE BARN GURU: How is the depth for each post determined? I’m assuming the soil type needs to be known, but is it ever the case where the structural integrity requires a deeper hole than the soil would allow without a massive auger? SAEPOR IN REYKJAVIK ICELAND
DEAR SAEPOR: Column depths and diameters are determined by the forces being applied to the column – wind, snow, seismic and applicable dead loads (weight of building). Unless otherwise informed, we generally use a value of 2000 psf (pounds per square foot) as an assumed soil bearing capacity – which is relatively conservative. Other than for extreme frost circumstances (such as where Hansen Buidings is – in Minnesota – which is 60”), rarely will a deeper column hole than 40 inches occur.
Mike the Pole Barn Guru
Nothing unreasonable at all. As I tell clients – your only limitations are imagination, depth of your pocket book and available space. We tend to attract clients who are looking for structural solutions everyone else will not touch. If you desire no interior columns, it can be done, we would utilize a set of parallel chord trusses at each side of your raised center to span from endwall to endwall. Trusses for 20′ wing as well as main (raised) center roof and floor trusses would be carried by these. These will limit your ability to place windows in kneewall above wings. Keep in mind, since loads on beams are a function of square of span, having columns at 30′ will reduce forces needing to be carried by a factor of four (and will similarly reduce your needed investment).
