This week Mike the Pole Barn Guru answers reader questions about replacing roofing with clip-lock standing seam and what the PBG recommends in the scenario, creating a wood shop in an existing structure and wondering if ceiling weight can be held, the possibility of removing knee braces in order to install a ceiling.
DEAR POLE BARN GURU: I am leaning toward replacing with clip lock standing seam on 2×4 purlins every foot on center. My installer wants to do away with the vapor barrier and stretch synthetic underlayment over the purlins. What do you recommend in this scenario? JAVO in PRINCE FREDERICK
DEAR JAVO: Clip lock standing seam panels have no ability to transfer wind shear loads and should only be installed over 5/8″ CDX plywood sheathing. If not, your building is likely to rack (or even fail) due to wind loads. There are other reasons to use sheathing: https://www.hansenpolebuildings.com/2015/08/standing-seam-steel/ In summary remove vapor barrier, install plywood with synthetic underlayment between plywood and standing seam steel.
DEAR POLE BARN GURU: Hello, I have an existing pole barn/garage but I have very little information about it. I would like to create an interior room for a woodshop but I don’t know if my trusses would support a ceiling and the necessary insulation. Is this something you can help with? CHAD in GRASS LAKE
DEAR CHAD: Unlike all Hansen Pole Buildings with spans of 40 foot or less (where we have our interior double trusses always designed to be able to support at least a minimal ceiling load of five pounds per square foot), most pole barn trusses are not ordered or designed to support any sort of a ceiling. Many times trusses will have a stamp on them stating truss spacing and loads, if so, you want a Bottom Chord Dead Load of 5 psf or greater. If nothing else, truss manufacturer’s stamp will tell you who fabricated those trusses and you can reach out to them to verify adequacy. If they do not have records available, or are no longer in business, you should engage a Registered Professional Engineer to perform a field inspection to verify adequacy, or to provide an engineered repair.
DEAR POLE BARN GURU: I have a 30′ x 48′ x12′ pole barn that has Knee braces. I am wondering if I am able to remove the knee braces on this type of rafter to eliminate having to cut around each one as I am installing interior liner steel. The rafter top chord is 2×10, the bottom chord and webs are 2×6 and the rafters are adjoined to the poles appx 30′ below the bottom chord. The rafters have fink style webs. JOSH in CANBY
DEAR JOSH: In fairly recently built pole barns, I would have encouraged you to reach out to whomever originally engineered your building. Your building obviously has been around (somehow) for more than a few years. I say this “somehow” in all seriousness as your roof system does look questionable. It very well could be compromised by any changes – even weight of steel liner panels. Best bet is this – hire an engineer to do an actual physical examination of your building to determine if knee braces can be removed, any structural changes needed if they are to be removed, as well as adequacy to support any sort of ceiling. Think of this as an investment, rather than an expense, especially if it prevents a failure.
For your walls, I would recommend unfaced Rockwool either R-30 with a well-sealed interior vapor barrier or R-20 with R-5 well sealed continuous insulation boards on the interior (Comfortboard® 80 or EPS).
DEAR POLE BARN GURU: Hello, I am building a 36x50x12 shop with 5:12 roof pitch, that will be conditioned space. The plan is to build out the interior with 2 small bedrooms and a bath then the rest open floor. I am putting in a ceiling at 12′ and will insulate the walls and ceiling leaving the roof uninsulated. Building is located in South Central Texas near La Grange. Does the roof need sheathing and felt or can I just lay the metal roof directly on the purlins? What about adding house wrap to entire building, walls and roof? Being in Texas, heat is biggest factor and with the a/c pumping inside I want to keep attic space vented correctly to keep moisture from building up. I plan to have large soffits to allow for soffit venting then ridge vent on roof. One of my biggest concerns is keeping out all the elements, including creep crawly bugs and concerned the garage doors will be source intrusions. It is my understanding that a sectional garage door is best for keeping out the elements vs roll up type. Can a garage door be truly sealed from all elements including bugs from crawling in? STEVEN in SUGAR LAND
