Tag Archives: ceiling loaded trusses

Pole Barn Insulation, Part II

Continued from yesterday’s blog:

(1) Storage – if you ever believe anyone might ever in the future desire to climate control then provision should be made for making it easiest to make future upgrades.

At the very least a reflective radiant barrier (single cell rather than wasting the money for the extra approximately 0.5 R from double bubble), an Integral Condensation Control (https://www.hansenpolebuildings.com/2017/03/integral-condensation-control/) or sheathing with 30# felt should be placed between the roof framing and roof steel to minimize condensation.

If a concrete floor is poured (in ANY use building), it should be over a well sealed vapor barrier.

For now we will assume this building is totally cold storage. If it might ever (even in your wildest dreams) be heated and/or cooled include the following in your initial design: Walls should have a Weather Resistant Barrier (https://www.hansenpolebuildings.com/2016/01/determining-the-most-effective-building-weather-resistant-barrier-part-1/) between the framing and the siding. Taking walls one step further would be ‘commercial’ bookshelf wall girts (https://www.hansenpolebuildings.com/2011/09/commercial-girts-what-are-they/).

In the roof – have the trusses designed to support a ceiling load ideally of 10 pounds per square foot (read about ceiling loaded trusses here: (https://www.hansenpolebuildings.com/2016/03/ceiling-loaded-trusses/). Trusses should also be designed with raised heels to provide full depth of future attic insulation above the walls (https://www.hansenpolebuildings.com/2012/07/raised-heel-trusses/).

Make provision for attic ventilation, by having an air intake along the sidewall using enclosed ventilated soffits and exhaust with a vented ridge.

Any overhead doors should be ordered insulated – just a good choice in general as, besides offering a minimal thermal resistance, they are stiffer against the wind.

(2) Equine only use: Same as #1 with an emphasis upon the ventilation aspect.

(3) Workshop/garage and (4) Garage/mancave/house are going to be the same – other than whatever the client is willing to invest in R value, being the major difference.

Adding onto #1 for the walls the low end would be unfaced batt insulation with a 6ml visqueen vapor barrier on the interior. Other options (in more or less ascending price and R values) would be Mineral wool insulation as it is not affected by moisture (https://www.hansenpolebuildings.com/2013/03/roxul-insulation/),  BIBs (https://www.hansenpolebuildings.com/2011/11/bibs/), closed cell spray foam in combination with batts and just the closed cell spray foam (https://www.hansenpolebuildings.com/2016/07/advantages-spray-foam-over-batt-insulation/).

For added R value and a complete thermal break, add rigid closed cell foam boards to the inside of the wall.

Once a ceiling has been installed, blow in attic insulation.

For (4) a Frost-Protected Shallow Foundation (https://www.hansenpolebuildings.com/2016/11/frost-protected-shallow-foundations/) with sand on the inside rather than a thickened slab is an excellent and affordable design solution.

For insulation solutions which follow the roof line, the best bet is going to be the use of closed cell spray foam, as it solves the potential condensation on the underside of the roofing and does not require ventilation above.

In most cases, the steel trusses fabricated for post frame buildings are either not designed by a registered engineer, are not fabricated by certified welders or both – so it makes it difficult for me to recommend them as part of a design solution.

With scissor trusses, they can be treated the same as a flat ceiling would be, provided the bottom chord slope is not so great as to cause blown in insulation to drift downhill.

 

Truss Repair? Don’t Skip this Step

A client writes:

“I recently purchased one of your pole barn kits to use as my home garage.  We have begun construction and have all the framing and the roof on.  I recently contacted my building designer about potentially getting the metal lining material for the ceiling and walls.  My designer told me that I can’t put a ceiling in because my trusses weren’t designed to handle the extra 5lbs per sq ft required.  This has got me a little confused and puts me in a bit of a jam.  If I can’t insulate and install a ceiling in my garage it doesn’t do me any good.  I’m just curious if this information is correct and if so what are my options at this point to ensure I can finish the ceiling of my garage??”

Pole Barn Ceiling Load TrussesTypically pole building trusses are NOT designed (by any provider or contractor) to support a ceiling load. The price to upgrade to ceiling loaded trusses is generally offered as an option on our quotes, and is typically fairly inexpensive. All too often, it is a case of a client trying to shave a few dollars and ends up being a case of “penny wise, pound foolish”. We do make every concerted effort to prevent truss repair issues, such as this client is now confronted with, from occurring.

It is important enough so as we specifically mention it in the terms and conditions of every purchase:

“Dead loads specified on engineered roof truss drawings include the weight of the roof truss. Roof trusses are NOT designed to support ANY hanging loads or ceiling loads other than those specified as special truss loads in the Agreement. In the case of design roof truss bottom chord loads of less than five (5) psf (pounds per square foot) the bottom chord dead load may be sufficient only to cover the truss weight itself and may not allow for any additional load to be added to the bottom chord.”

In many cases it may be possible for an engineered truss repair to be made, to upgrade the load carrying capacity of the bottom chord of the trusses to 5 psf. I’m sorry to say, this is not free. The truss company’s engineer will need to put his license on the line in designing a “fix” for trusses which were designed for a load other than is now intended.  It’s not the same as designing the original trusses.  If you think about it, redesigning and augmenting something you have built, is always more time consuming (and brain challenging!) than the first time around. His time and expertise are not without a charge.  It’s not usually “much”, like a couple hundred dollars.  Then there is our time, as changes like this are not included in the basic cost of your building kit.  Again, we don’t charge “much”, but our time is worth something as well. The cost of materials to fix it…one last cost if you are doing the truss repair yourself.  If not, a contractor’s charge must be added.  All totaled, it could run you anywhere from a couple hundred dollars to over a thousand or more, so you can see why we diligently try to get folks to “do it right the first time”.

When ordering a building from anyone, if there is a suspicion anyone might ever consider putting a ceiling in – it is always prudent to err on the side of caution, and spend the extra few dollars to include the load carrying ability in the original design. Truss repair is not my idea of “fun”.

How to Design a Climate Controlled Pole Building

When I first entered the post frame industry over three decades ago, most pole buildings were barns. Having a climate controlled building  (heating and cooling) was rarely a consideration.

Modern pole buildings, serve a plethora of purposes from homes to offices, retail space to churches and everything in between. HVAC (heating, ventilating and air condition) becomes an important consideration.

This blog is nowhere near an in depth guide to climate control, but intended to give the reader a starting point.

The first stop should be to check the recommended R-value calculator:

https://www.ornl.gov/cgi-bin/cgiwrap?user=roofs&script=ZipTable/ins_fact.pl

If starting with a concrete slab on grade, a layer of A2V insulation should be properly installed below the slab.

Walls should be framed with bookshelf style girts placed at 24 inches on center. Also referred to as commercial girts, they create an insulation cavity, which allows for fiberglass insulation batts to be installed horizontally between the wall girts. If steel siding is used, it could be beneficial to use a quality housewrap between the wall girts and the siding. With commercial girts, to properly size the insulation cavity, create a space equal to the depth of the pole, plus the 1-1/2″ outside of the posts where girts extend. This allows for drywall to be attached to the inside face of the wall girts, creating a smooth wall surface.

Another great option for wall insulation is BIBS – which provide a higher R value than batt insulation, as well as filling all of the voids.  If you are not familiar with BIBS, check out their website: https://www.bibs.com

As a sidebar, I have BIBS in my large three story (84’ x 60’) accessory  climate controlled building (yes, it’s a pole building).  The cost savings on our heating and air conditioning bills is testimony in and of itself for this great product.

Ceilings – use ceiling loaded trusses with ceiling joists 24″ o.c. Sheetrock can be attached to the underside of the ceiling joists and insulation can be blown in above.

Any time a dead attic space is created – the attic space MUST be ventilated. As long as 1/2 of the required ventilation area is in the upper 1/2 of the attic, the area of the attic vents must be 1/300th of the footprint area of the attic. Otherwise, 1/150th is required. The best way to get even attic airflow is to use enclosed vented overhangs in combination with a vented ridge.

As I said, this is a primer for how to ensure a climate controlled pole building.  Ask whoever is designing your new building for more assistance. I have far more concerns for folks wanting to over-design climate controlling their new pole barn, then “under”.  While I want you to be warm (or cool) and comfortable, I also want to be sure you are using the “Three R’s Rule” – selecting the right product, to do the right job, at the right price.