Tag Archives: Barrier

Ceiling Liner, Double trusses, and a Second floor

This Wednesday the Pole Barn Guru answers reader questions about what best installed between ceiling liner and trusses and insulation recommendations in a new shop, advice on sidewall column size for use with double trusses, and the structural stability of a pole barn second floor.

DEAR POLE BARN GURU: Just built a 40x60x11 pole barn on the eastern shore of MD. Approx. 20×40 will be garage workshop, the rest will have a kitchen and bathroom etc. going to use liner panel for ceiling, what do I, if anything needs to use between the liner and the trusses? Insulation recommendation? Product recommendations are appreciated! Thank you, LYNN in SHARPTOWN

DEAR LINN: There is not a Code requirement for a barrier between trusses and liner panels in your climate zone. If you are considering blowing in cellulose, chemicals in cellulose can react with steel panels to cause premature deterioration, so a barrier should then be used. My first choice would be blown granulated rockwool, second would be fiberglass. Make sure to have adequate eave and ridge ventilation, in correct proportions.


DEAR POLE BARN GURU: Went reading your blog on double truss system, if wanting to erect a pole barn 30×78. Would using 4×6 be ok going 12 ft high post spaced every 8 foot other then 2 16 openings. BRIAN in PADUCAH

nailing trussesDEAR BRIAN: Thank you for being a reader of my articles. Even with a very low design wind speed, low risk occupancy and a well-protected site, it is unlikely 4×6 columns would be adequate to properly carry design loads, given your eave height. As you are possibly considering utilization of ganged (double) trusses, and will need larger columns anyhow, you may want to consider increasing column spacing to 12 feet on center. Fewer holes to dig, fewer columns to set and your budget will be much happier. In any case, I would encourage you to invest in a fully engineered building – any possible savings you might believe you would attain without engineering, will be quickly eaten up when you have a failure.


DEAR POLE BARN GURU: I’m wondering if this would be structurally sound with a top floor on it? It would be meant as a home/business. I work in the commercial construction industry I guess the other question is do you have any of these in New Hampshire? Please let me know what you think and Thank you. JOE in HUDSON

DEAR JOE: My own post-frame building has a 48′ x 60′ main center section. Downstairs has a clearspan floor (yes, spanning 48 feet), with a 16 foot high ceiling. Upstairs is a full living area, again with 16 foot high ceilings. A portion of this upper level also has a small mezzanine. Overall building height at peak of roof is 44 feet. So, in answer to your question – fully engineered post-frame construction lends itself very well to multiple stories (up to three stories and 40′ tall sidewalls, or four stories and 50′ tall sidewalls with fire suppression sprinklers). We have provided over 100 of our buildings to clients in New England states, including a dozen or so in New Hampshire.


Pole Barn Bid, A1V Barrier, and Definitions

DEAR POLE BARN GURU: I am bidding on a simple 80×140 pole barn with 12′ sides. I can’t come up with something reasonable. What would you bid. I need help. Last time I did it wrong and it hurt financially. Thanks. JASON in MINBURN

DEAR JASON: As you probably found out on your last post frame building project, they are far more than just simple barns, especially when they get to this sort of footprint. Our buildings will not be the least expensive, as there is always going to be someone out there who is willing to sacrifice quality for price. What you will get is the best possible building value for your investment. You will be hearing from one of the Hansen Pole Buildings’ Designers shortly.

DEAR POLE BARN GURU: So I decided to put up a pole building for a garage. I bought a standing roof kit, 30×50 with 12″ eaves and steel trusses that are arched in the middle of the building, for future dreams of having a car lift. My trusses have brackets welded on them for my 10′ 2×6 purlins to run in. My question is, do I need some sort of vapor barrier in between my metal roof and my purlins? My purlins run horizontal, I plan to use vented soffit the whole way around the building, 2 gable vents, and it also has a ridge vent. I will frame inside underneath the lowest point of my truss and insulate above that. It will leave about a 16″ gap between my interior ceiling and the steel roof. Thanks for the help. BRYENT in OHIOVILLE

Reflective InsulationDEAR BRYENT: Yes – it is essential you have a vapor barrier between the roof purlins and the steel roofing. I would recommend using A1V (aluminum one side white vinyl inwards toward conditioned space. Hansen Pole Buildings has six foot net coverage rolls in stock for immediate shipment. These rolls have a tab on one edge which has an adhesive pull strip – so no rolls of tape to deal with.

Code does not allow for gable vents to be used in conjunction with eave and ridge vents. It is one or the other and I would pick eave and ridge for the most uniform ventilation.

DEAR POLE BARN GURU: What defines a pole barn? The last building I put up on my property is an all steel truss roof structure and the foundation has 3’x3’x3′ footings at each of the six columns. What is the foundation used? STEVE in PALMDALE

DEAR STEVE: Technically a “pole barn” is a post frame building. Below is the definition for a post-frame building system from ANSI/ASABE S618 Post-Frame Building System Nomenclature. This standard was written to establish uniformity of terminology used in building design, construction, marketing and regulation.

Lean BuildingA building characterized by primary structural frames of wood posts as columns and trusses or rafters as roof framing, Roof framing is attached to the posts either directly or indirectly through girders. Posts are embedded in the soil and supported on isolated footings, or are attached to the tops of piers, concrete or masonry walls, or slabs-on-grade. Secondary framing members, purlins in the roof and girts in the walls, are attached to the primary framing members to provide lateral support and to transfer sheathing loads, both in-plane and out-of-plane, to the posts and roof framing.”