Tag Archives: vented closure

The Shell or Interior, an Old Barn Fix, and Ventilation

Today’s Pole Barn Guru answers reader questions about inclusions of a Hansen Building Kit, some guidance with the renovation of an old barn, and how many sq inches of NFVA do foam enclosures have?

DEAR POLE BARN GURU: What does it include? Just the shell or interior also? ASHLEY in MONROE

DEAR ASHLEY: We typically provide detailed engineered plans, all verifying structural calculations, step-by-step installation instructions and materials delivered to your site for complete building shells (including doors and windows), as well as any raised wood floors and stairs. Interior stud walls (to create rooms) are usually best acquired from any nearby lumber supplier, as they are non-structural and do not support any roof or exterior wall loads. While we have provided interior wall materials, since we only send our clients very high graded lumber, it is typically not your most economical design solution.

 

DEAR POLE BARN GURU: I have an old barn, built early 1900s. A lean-to was added somewhere in the 60s. The barn is collapsing but the lean-to part is still good, size 36×24. I want to add a new posts and header for the rafters replacing the barn wall 36′ length. I plan to use wet set brackets and 6x6x16 post. I am not able to set post in the ground without removing the roof. Is 4 poles with 12′ spacing enough support? The barn, what’s left will be removed afterwards leaving an open side to put equipment in an out. DOUGLAS in TIPTON

DEAR DOUGLAS: Adequacy of those columns is going to depend entirely upon actual dimensions of your 6×6 columns, their grade and species, roof height, design wind speed and wind exposure, roof snow load, type of roofing and siding (both for weight and deflection purposes), among just a few determining factors. While what you have may very well be adequate, you should reach out to a Registered Professional Engineer to verify. Travis McDaniel of MSS Engineering is based in Indiana and would be an excellent choice to contact, as he has extensive post frame (pole barn) experience. His number is (574)855-6131.

 

vented-closure-stripDEAR POLE BARN GURU: Pole barn has metal roof with ridge vent and vented foam enclosures. How many sq inches of NFVA do foam enclosures have? TOM in ROYAL

DEAR TOM: It will depend entirely upon what brand of vented foam closures you have. We provide a Marco LP-2™ ridge vent (read more here: https://www.hansenpolebuildings.com/2014/12/ridge-vent/ with 18.4 square inches of net free ventilation per lineal foot of ridge when placed on each side of ridge, provided roof steel’s upper edges from each side are at least 1-9/16” apart.

Ceiling Addition, Drywall Orientation, Ridge Vent Replacement

This week the Pole Barn Guru addresses reader questions regarding the ability to hang a ceiling addition in a Hansen Building, if it is better to hang drywall parallel or perpendicular to framing, and if Hansen can replace a ridge vent in Buffalo, NY

DEAR POLE BARN GURU: I purchased a 25′ x 35′ kit from you and was wondering if I can hang a ceiling in my pole barn? I have 11′ or 12′ trusses on center and was worried about the strength of the trusses to hold more weight. THOMAS in NEW TRIPOLI

DEAR THOMAS: Your building’s roof trusses are designed to support a five (5) psf (pounds per square foot) dead load from the bottom chords. This would be sufficient to carry 2×6 ceiling joists 24 inches on center on hangers between bottom chords, as well as 5/8″ gypsum wallboard (drywall) and blown in or batt fiberglass insulation.

Please note – in your provided photo wall girts have been externally mounted, they have been engineered to be placed bookshelf style, as externally mounted girts on 11′ and greater spans will fail due to bending and will excessively deflect. They should be removed, trimmed and placed to match engineered plans. Also – end trusses are to be notched into columns 1-1/2” to provide proper and adequate bearing. They should be carefully removed, notches cut, then properly placed.

 

DEAR POLE BARN GURU: I got my final inspection last week, so I have finished the workshop according to the county. Now I am working on the insulation and interior wall and ceiling finishing. For insulation, I am using R-19 craft faced batting for both walls and ceiling and might later add blown in above the ceiling to further increase the R value.

I have a question on the best orientation for the drywall for ceiling and walls. It seems that running the sheets perpendicular to the ceiling purlins and commercial girts would provide greater strength than parallel. What is your experience? I am planning on using 5/8 inch board.
Thanks, LEE in HUNTSVILLE

DEAR LEE: For best installation you will want to run drywall perpendicular to framing (e.g. vertically on walls) https://www.hansenpolebuildings.com/2019/09/11-reasons-post-frame-commercial-girted-walls-are-best-for-drywall/
Ideally, you should use unfaced insulation in your ceiling, this allows any warm moist air within your building to escape into attic space and be properly exhausted through ridge vent.

 

DEAR POLE BARN GURU: You’re listed as building pole barns in Buffalo, NY. I want to find someone that can replace my ridge vent that goes the full length of the building. Who do you recommend in the area and what choices do you have for a new vent for me? GARY in BUFFALO

vented-closure-stripDEAR GARY: If your steel panels are 3′ wide, with 5/8″-3/4″ high ribs every 9″ we can provide form fitted ridge closures, if so, please reach out to Materials@HansenPoleBuildings.com with your zip code and length of ridge line for pricing and availability.

Most of our clients are DIYers, should you need an installer, we would suggest your try posting in your nearest Craigslist under “GIGS”.

Steel Ridge Cap to Roofing Overlap

Hopefully no one wants to create a roof with leaks. Reader MIKE in HARBOR CREEK wants to make sure he is doing things correctly. He writes:

“How much overlap do you have to have with roofing and ridge cap? Is 2.5″ enough and then you use metal to metal screw you do not have to penetrate the purlins?
Ty”

I cannot vouch for how other building providers assemble their buildings, so I will go with how we do it.

To calculate a building’s roof steel length we take one-half of the building’s span (or horizontal measure from peak/ridge to the outside of columns) and multiply this times a factor for roof slope. 

For slope factor – multiply slope by itself and add 144. Take the square root (use a calculator) of this number and divide by 12.

Example to calculate slope factor for 3.67/12:  [3.67 X 3.67] + 144 = 157.47. Square root of 157.47 = 12.549. Divided by 12 = 1.0457.

For a 40 foot width gabled building with a 4/12 slope this length would be 21.082 feet (call it 21’1”).

Outside of columns at eave we have a 2x of some sort as an eave strut, with a width of 1-1/2 inches and roof steel must overhang this by 2-1/4 to 2-1/2 inches. Using 21’1” for our roof steel length, this means the top edge of roof steel will now be four inches from the peak/ridge.

Standard steel ridge caps are generally very close to 14 inches in overall width, giving somewhere around three inches of overlap on each side. Placed in this overlap will be either a form fitted outside closure strip or a vented closure (https://www.hansenpolebuildings.com/2015/11/ridge-cap-foam-closure-strips/). Either of these products properly installed will prevent weather (rain and/or snow) from being driven beneath the ridge cap into your building. You can read a little more on correct placements of closures here: https://www.hansenpolebuildings.com/2015/11/outside-closure-and-vented-closure-installation/.

By using metal-to-metal stitch screws to attach the ridge cap to high ribs of roof steel, there is no need to have to miraculously hit any ridge purlins with screws. Here is a brief tale involving a builder who went off on his own tangent https://www.hansenpolebuildings.com/2011/12/stitch-screws/.

In summary Mike, provided you have a 2-1/2 inch overlap, have used proper ridge closures and stitch screws your life will be good and you will have a happy end result!