Drill Stem Shop

[mateo270]

I have seen sheds and barns made of drill stem before, but I have searched this site and google and can't really find any pictures or examples.

I am thinking using 2 7/8 for posts and 2 3/8 for trusses. I have seen standard pitched trusses as well as trusses where the top member is bow'd or arc'd over a horizontal member, with supports welded between. Most seem to have been 30' spans, a little shorter than a typical stick of drill stem.

My question: How do these trusses perform compared to other options? What kind of spacing would I need using these trusses for a hay shed in south Texas (12' tall, closed on 3 sides with perlins and tin)?

[DSW]

Pipe is usually a poor choice for a truss, unless it's over built or well engineered. Other shapes are usually much better in bending than a round tube. IF a truss is well designed and the loads are applied at the joints, then the tube will work well in compression and not want to bend. Pipe takes tension and compression forces well, but really is poor in resisting lateral bending loads. Angle, rect box tube, I beams are usually better choices for bending loads. The problem is that many roof structures tend to transfer loads to the truss as a uniform load bearing member and not as a true truss with point loads.

A true arch is probably the exception to this. By nature an arch is a compressive structure. The tube gains strength by being bent against the bending force that is applied. The forces are easily changed to compressive forces that easily travel down the pipe. The issue here is that an arch usually ends up with a very high lateral load that can not be taken easily by standard columns. You need to either have columns that can resist this outward force, or tie the two sides together so they resist each other.

[mateo270]

Pipe is usually a poor choice for a truss, unless it's over built or well engineered. Other shapes are usually much better in bending than a round tube. IF a truss is well designed and the loads are applied at the joints, then the tube will work well in compression and not want to bend. Pipe takes tension and compression forces well, but really is poor in resisting lateral bending loads. Angle, rect box tube, I beams are usually better choices for bending loads. The problem is that many roof structures tend to transfer loads to the truss as a uniform load bearing member and not as a true truss with point loads.

A true arch is probably the exception to this. By nature an arch is a compressive structure. The tube gains strength by being bent against the bending force that is applied. The forces are easily changed to compressive forces that easily travel down the pipe. The issue here is that an arch usually ends up with a very high lateral load that can not be taken easily by standard columns. You need to either have columns that can resist this outward force, or tie the two sides together so they resist each other.

Thanks. All the things you mentioned here make sense and I understand that a pipe is not an optimal supporting member for a roof load.

But I have seen these and know that they can be used. I already have these materials and would like some feedback from someone who has used them in this application.

[RancherBill]

DSW hits the nail on the head, but.....

There are lots of pipe buildings. Look at greenhouses. You can make them out of PVC is you want.

http://farm3.static.flickr.com/2640/4178478763_c1fa6a6b9b.jpg

but they sometimes fail.

http://farm3.static.flickr.com/2642/4208517631_3999fde62a.jpg

Having said that, it is common to have pipe greenhouses. I would look for local greenhouse supplies and see what they are selling for your area. They could probably give you the name of somebody local that you can go and see their building. They know what the roof load, wind load etc are for your area. I 'overbuild' one of their designs.

Just on pretty pics of greenhouses.

http://www.rimolgreenhouses.com/product_info.php?cPath=22&products_id=563&gclid=CMf4jI74_p8CFRFbagodwH7elw