DEAR POLE BARN GURU: Could you tell me the pitch of the roof…for small pole barn…..front wall is 10 foot high…back wall is 8 foot high…rafter span is 13 feet. HERBERT in HAMPTON
DEAR HERBERT: Roof slopes are expressed as the number of inches of rise per 12 inches of run. 24 inches of rise in 13 feet of run would be a slope of 1.846/12 or 8.745 degrees. Some cautions – if you intend to use steel roofing, chances are excellent the paint warranty will be voided due to a roof slope of under 3/12. The side laps of each panel should also have strip mastic placed on top of the under laps to assist in preventing leaks. This slope is also too flat for shingles, unless special considerations have been made for underlayments (most Building Departments require 90# felt paper or an equivalent). I’d recommend you increase the roof slope to 3/12 or greater.
DEAR POLE BARN GURU: Can I order specific species with my kit? I’d prefer Doug fir for all the wood, including PT.
Can I choose heavier gauge steel panel for roofing and siding than 29 gauge?
Thanks. JEFF in GREENVILLE
DEAR JEFF: You can specify a specific species, however be prepared to pay a premium for doing so, especially in the case of the pressure treated wood. Douglas Fir does not take pressure treating well, so only a few limited chemical formulations are available which will work with it – some of which happen to be highly corrosive to steel. This results in having to place a barrier between the treated lumber and the steel siding, as well as the use of heavily galvanized or stainless steel fasteners.
Most roof truss manufacturers will not guarantee a specific species of lumber will be used in their trusses – so this could become problematic, in your case.
Please read more about lumber species choices here: https://www.hansenpolebuildings.com/2012/03/lumber-species/ (please note this article was written prior to the design values for Southern Pine being reduced).
You may also choose heavier gauge steel panels, however you should read this article first: https://www.hansenpolebuildings.com/2012/01/steel-thickness/
DEAR POLE BARN GURU: We built a 30 x50 pole barn with 2 10 ft attached sheds about 1 1/2 years ago. It has sprayed foam insulation and finished inside with sheet-rock. Our problem is every time it rains hard it leaks at the corners on one end. Any suggestions of what we could do to try and find the leak? Thank you so very much for any information you could give us. MARK in SASAKWA
DEAR MARK: I am going to take a WAG (Wild Arse Guess) here. The guess is actually probably not overly wild, since you are telling me the leaks only occur at one end of the building and happen on both sides of the roof.
Your building is 50 feet in length, which means it took 16-2/3 sheets of three foot wide roof steel to cover each side of the roof. This is with the assumption your building has no endwall overhangs. This also means the last sheet of roof steel on one end had to be ripped lengthwise to remove the extra foot of steel. When the rake trim was then installed, there was not a high rib of steel under the trim. When it rains (or snow falls on the roof and melts) water seeps under the edge of the rake trim and into your building. If indeed this is the case, the rake trims on the offending end can be unscrewed, and strip mastic can be used between the edge of the rake trim and the roof steel to keep the water from going where it is not intended to be – screw the rake trim back into place and all should be good once again!
Let me know if this is not the case and we can look for other solutions.