Tag Archives: girts

Bookshelf Girts or Stud Walls?

Why Use Bookshelf Girts Rather Than Studs?

Long time readers may recall my Grandpa Pete was a home builder and his sons – Sid (my father), Neil, Lyle, Gil, Dave and Amund were all framing contractors. https://www.hansenpolebuildings.com/2011/06/before-the-pole-barn-guru/. Besides being raised with “wood is good”, I had a concept of vertical stud walls permanently ingrained in my head!

Stud walls led to my losing my posterior erecting my first post frame (pole barn) building. I struggled with this 90 degree ‘flip’ in framing concept far more than I needed to. Luckily, I was able to wrap my head around left-to-right rather than up and down when it came to my second building and I actually made some very good money!

Reader TRENT in WALLA WALLA writes:

“I am currently working on plans for building my first post frame home. It will be 30×48 single story. I am trying to figure out the best wall girt design. I am looking at going with 2×8 bookshelf wall girts or vertical stud walls between the posts. I see more people going with bookshelf girts vs vertical studs. Is there any drawbacks or reasons not to use vertical stud wall framing between the posts?”

Mike the Pole Barn Guru responds:

Installing a ceilingPretty straightforward – vertical stud walls will take more lumber. Besides increased material investment, more pieces mean more connections and more labor.

Imagine, if you will, a pole building with a 10′ eave height and columns every 12 feet. Bookshelf girts take (1) 2x4x12′ pressure treated, (4) 2x8x12′, (2) 2x4x8′ for blocking girts ends and (2) 2x4x12′ to attach drywall at the ceiling level – 98.67 board feet of lumber. For stud walls (1) 2x6x12′ pressure treated, (7) 2x6x10′ studs, (1) 2x6x12′ top plate, (1) 2x4x12′ to attach drywall at ceiling level, (4) 2x4x12′ horizontally to attach steel to wall studs – 134 board feet of lumber. From a structural aspect, care will need to be exercised in attachment of the top plate and end studs to adequately transfer wall bay wind loads to columns. It may necessitate some sort of Simpson strap to properly anchor the plate to columns.

 

 

 

 

Rough Cut Lumber, Insurance, and Girt Orientation

DEAR POLE BARN GURU: Hi, I’m planning on building a ( 32’ x 60’ x 12’ ) Pole Barn with 4/12 scissor truss.  I want to price out rough cut lumber on walls and ceiling.  How do I calculate the

Amount of board feet lumber I need to cover the walls and ceiling.

Thanks BRIAN

DEAR BRIAN: The first thing you should do is to consult with the engineer who has designed your building to find out if he or she will approve your use of ungraded rough cut lumber (which, unless you season it thoroughly, is going to have a very high moisture content and is going to be prone to warp, twist and shrink as it dries). I cannot imagine very many registered design professionals who are going to approve with the proposed use of your material. In the event you are considering constructing a building without having an engineered set of building plans which are designed specifically for your site and your building – you are putting yourself, your loved ones and your possessions at serious risk. The few dollars you might save by not having engineered plans are just not worth it – please do not be penny wise and pound foolish.

Back to your question – you can take a count of the boards on your engineered building plans which will give you the required lengths and quantity required.

DEAR POLE BARN GURU: Need an insurance company that will insure 1/2 acre lot with a pole barn that is adjacent to 1/2 acre lot with a lake house but on two separate deeds. FRANK in LOUISVILLE

DEAR FRANK: I would suspect any independent insurance agent can find you several companies who would happily write a policy for you. Try calling one or more in your area.

 

DEAR POLE BARN GURU: Can you explain girt detail why the 2×6 are placed horizontal and not vertical and why they hang off 1.5 inches past the columns? OWEN in FLORA

DEAR OWEN: This article explains the why of how the wall girts are oriented: https://www.hansenpolebuildings.com/2012/03/girts/

They hang 1-1/2″ outside the columns so the outside face is in the same plane as other members such as the 2×8 pressure preservative treated skirt board, large door headers, etc. It also allows for any wiring to be placed horizontally without having to drill through columns.

 

 

Drywall Idea, Bolt Counts? and Don’t D-I-Y This!

DEAR POLE BARN GURU: Will I have problem with moisture in the wall if I nail drywall to the gerts and leave the 6×6 poles exposed? I may put a stove for heat in it while I am in it occasionally. I have insulted the roof. Concrete floor. JAMES in NEW ALBANY

DEAR JAMES: Provided you have a good building wrap between the siding and the wall girts (read more about building wraps here: https://www.hansenpolebuildings.com/2012/11/house-wrap/), as well as a well-sealed vapor barrier between the girts and the drywall, you should be able to minimize the effects of moisture in the wall.

Now your bad news. I will take a wild guess and surmise your post frame building has girts nailed flat on the outside of the columns. If so, and you attempt to drywall to the inside face of the girts, be prepared for infinite issues with the drywall joints cracking due to excess deflection.

If there is no building wrap, a quick and easy fix is to have an inch or more of closed cell foam insulation sprayed on the inside of the siding.

I’d most probably either build a vertical stud wall between the columns, or place another set of horizontal girts on the inside of the columns. Either of these would afford an insulation cavity with enough depth to make a difference. This would allow BIBs insulation to be blown into the wall with a minimal number of heat transfer points.

DEAR POLE BARN GURU: How many lag bolts should be used in a 4 x 6? This is for the truss supports. COREY in PAW PAW.

nailing trussesDEAR COREY: My educated wild guess is your post frame building has trusses placed on top of a truss carrier (basically a header from column to column).

You can find the size and number of required fasteners by looking at the data prepared by the engineer who designed your building, as this information will be on the sealed plans.

Numerous factors would be involved in the determination of adequate fastening. If the carriers are notched into the columns, far fewer fasteners will be required, as they will only be needed to resist wind loads.

If the carriers are placed on the sides of the columns, then the roof load is typically the governing factor. The fasteners then have to resist the live loads (snow and any attic bonus or storage space) plus the dead loads (weight of roof system and covering, as well as any ceiling.

The spacing of the columns and span of the truss impact the number of fasteners as well.

If for some reason this information is lost or missing from your plans, a competent local RDP (Registered Design Professional) should be engaged to provide a connection design for you, as this is hugely critical to prevent unexpected failures which could result in bodily harm or death. DO NOT GUESS.

 

DEAR POLE BARN GURU: How can I build a strong 30 foot truss that won’t sag. LARRY in TYLER

DEAR LARRY: I hate to just throw out the obvious, but in your case I will – DO NOT BUILD YOUR OWN TRUSS.

Prefabricated metal connector plated wood trusses are nothing short of an engineered miracle. You can have them designed to support any load which you can conceive of, have them delivered to your site and engineer sealed drawings are provided to confirm the required load conditions are met.

A quick Google search of “Tyler Texas Wood Roof Trusses” will give you several possibilities to discuss your needs.

 

 

Commercial Girts Best for Drywall, Site Prep, and Condensation

DEAR POLE BARN GURU: I’m considering a pole barn for my residence but had a question about the girt placement between posts. I read in the FAQ section that they are placed like shelves between posts. Would it be possible to mount drywall directly to these for interior walls without additional bracing or building of interior wall frames? I’m trying to avoid framing an entire building within a building, it seems pointless and not cost effective. If I need to frame every interior wall to hold drywall and insulation, I can simply build a standard stick frame house. VAN in INDEPENDENCE

Installing Drywall on CeilingDEAR VAN: Bookshelf girts for insulation (e.g. Commercial Girts) is a quick and easy way to create a deep insulation cavity as well as providing the framing for your interior GWB (Gypsum Wall Board). You will want to confirm your new post frame building frame is stiff enough to prevent undue deflection from cracking the GWB joints.

Learn more about commercial girts here: https://www.hansenpolebuildings.com/2011/09/commercial-girts-what-are-they/.

DEAR POLE BARN GURU: I have property in an area that floods from time to time. For example, can a monitor barn (approx. 25×50). with side sheds be built. The idea I have is the side sheds serving as porches and under the barn would be a drive through area. there is already a modular home built in the area that is elevated about 4 ft. off the ground and they have had no problem . Thanks, MIKE in MOLINA

DEAR MIKE: You can build any sort of post frame building on your site which will be allowable under the limitations of your Planning Department. As to dealing with the flood issues, you should have your property elevations determined by a surveyor, and the site where the building will be constructed can then be built up so the floor will be above the flood plain level.

 

DEAR POLE BARN GURU: I recently purchased several 4’x50′ reflectix double bubble foil rolls. I’ve put up a brand new 30×56 post frame metal building and was going to use this product to keep the metal roof and walls from condensating not to mention I was hoping it would help keep some heat in during the winter and heat out during the summer until I truly insulate the inside. My question is, for ease of installation on my metal roof panels, is it acceptable to put the foil on the underside of the 2×6 roof joists instead of sandwiching it between the roof joists and metal? There will be no roof venting due to leaving the trusses and attic space exposed. My only real concern is that it could condensate worse installing it this way. Also I will not be continually heating the building. Only on occasion with a propane heater while I’m working. I’m not real savvy when it comes to insulation and condensation control so any advice would be appreciated. Thanks in advance! Brandon

DEAR BRANDON: While it would be easy to install the steel roofing without having to place the reflective radiant barrier between the roof purlins and the roof steel, it is going to be the easiest method to limit condensation issues, given the product you have invested in. Hopefully you have gotten the double bubble with a tab along one side and an adhesive pull strip, otherwise you will have to tape all of the seams as you work your way along the roof.

Could you place it on the underside of the purlins? Yes, however in order to work as an effective condensation control, it has to be absolutely tightly sealed against any protruding framing members. Remember the time you saved on installing the roof steel? You just ate it all up.

If you have not yet ordered your steel roofing you could resell the reflective radiant barrier online and order steel with I.C.C. (Integral Condensation Control) attached (see the article and video here: https://www.hansenpolebuildings.com/2017/03/integral-condensation-control/).

 

 

Pole Building Wall Girts

Movin’ On Up!

Well Leroy will never be confused with Sherman Hemsley of the iconic TV series “The Jeffersons” but his crew was certainly movin’ on up!

Leroy mentioned the man he works for provides neither plans nor a materials list for his crew to build from. They just make the building “work” from the materials which are dropped off. Somehow, this seems less than scientific, especially as they cut all of the notches in the columns for the single trusses spaced every eight feet, then had to go back and cut them all again! It seems they had forgotten to compensate for the purlins, which would run over the tops of the trusses. The crew easily burned several hours in this adventure!

It was of interest to hear Leroy espousing how much money was being saved by his employer using rough cut 5×6 (yes, 5×6 for those in most of the rest of the country) for posts instead of surfaced 6x6s.

At 4-3/4” x 5-3/4” the Section Modulus of the rough 5×6 is 26.17, as compared to the slightly greater 6×6 at 27.73 (within 6% anyhow). As long as the site of this building was Exposure B or C for wind, either size would work – Exposure D, either is a failure (assuming we are talking about Southern Pine lumber, not some lesser species).

For more fun with posts: https://www.hansenpolebuildings.com/2014/08/lumber-bending/

What I found particularly interesting was the attempts to cut truss notches in the posts, while they will settle further into the ground due to the lack of an adequate footing underneath. If you didn’t read the past two days’ blogs, go back and find out how much concrete was put in the posts, and why it’s nowhere near adequate to keep this building from settling (or heaving due to frost).

I’ve always built by doing the roof first, it made things easier to square up. Leroy’s boys were putting up wall girts as quickly as they could, however. I was impressed by the use of 2×4 1650 msr lumber for the wall framing. This was the first good idea I found my neighbor’s pole building experience.

Learn about msr lumber here: https://www.hansenpolebuildings.com/2012/12/machine-graded-lumber/

Pole Barn Wall GirtsOn this building, the girts were unusually spaced – 31 inches from the top of the pressure treated skirt board, to the bottom of the first girt, then 25-1/4 inches on center above. This means the bottom girt has to carry a tributary load of 29 inches.

With an Exposure B wind condition, they will carry the bending loads (https://www.hansenpolebuildings.com/2012/03/girts/), however with spans of greater than 24 inches on center, which they all are, results in excess deflection beyond the limitations of the building codes. Adding two more rows of wall girts would have at least been something to even things out.

Now the clincher –only the 40 foot sidewalls were framed prior to all of the windows and the entry door being installed. No apparent attempt was made to insure the corners were plumb, and no apparent connection to the other walls was constructed. The entry door was installed without adding a post on one side for stability! It just sort of “hung there” on the one post.

On the windows, if the wall has to be racked very far to have a plumb corner, undue stresses will be placed upon the frames, resulting in windows which bind when being opened, or possibly cracking from the stresses induced! I’d not want anyone standing below this building if they do decide to square it up.

Come back next week and we’ll see if this saga comes to a close!

Purlins: Missing Screws

Just in case I have never mentioned how much I appreciate the questions posed to me by Bob, one of the Hansen Pole Buildings’ Designers, I will do so here.

Bob writes,

I got into a discussion with a gentleman in Kansas that liked our design approach (post spacing, double interior trusses, purlins on edge, etc.) but has no faith at all that he or his crew would hit all of the purlins on edge with the roofing screws.  We discussed pre-drilling and I had him off the ledge, but when the discussion of book shelf girts came up, he started breathing hard again.  Now I’m pretty sure book shelf girts is the only option these days for any pole barn, but it seems I’m dealing with a client that is afraid of pre-drilling and his ability to square his roof and building.

One of your blogs describes the simple fix for a missed hole (“Either push the underlying purlin up towards the peak of the roof, or push it down towards the eave line until the pre-drilled hole aligns with the center of the purlin.”) but I’m having trouble imagining being able to push a purlin that is in place that far.  And if a purlin is pushed into position as described, what happens upon release?  Maybe this is a situation that I could appreciate more with personal experience, but I’m not getting there with my imagination alone… and as a result I won’t be terribly convincing that it’s really that easy.”

The beauty of pre-drilling pilot holes for roof and wall screws is perfectly straight lines. Straight screw lines are truly a thing of beauty – there are few things in life as pleasing as looking across a wall or roof and seeing the screws lined up like soldiers.

In an ideal world, every piece of lumber would be absolutely perfectly straight, and remain this way forever. Lumber, even though it is produced in a factory (a sawmill), is organic – it really wants to return to its nature as a tree. This means it wants to warp, twist, cup, crook or otherwise deflect.

The wonderful thing about lumber is it will flex a long way in the weak (1-1/2” narrow direction). This is exactly why wall girts placed flat on the outside of columns rarely meet the requirements of the codes – they deflect too far!

With both ends of a roof purlin restrained by an engineered joist hanger, or wall girts restrained at each end by solid blocking, the only portion of the framing which will be a potential for a “shiner” is as the girt or purlin approaches the middle of the span.

In the Hansen Buildings product guide (downloadable free on our website), is a photo of my feet (seriously) – as I stand on a 2×6 laid flat (I am standing on the wide 5-1/2 inch face. The 12 foot long 2×6 probably bends close to six inches at the center!

Whilst Bob (and his client) may be concerned about the ability to move purlins or girts up or down, the reality is – wood is forgiving, it can be moved remarkably easily to where it should have been had we been living in the previously mentioned ideal world.

And remember, steel roofing and siding functions much like very strong, very thin plywood. Once the screws are in place, the strength of the screws and the rigidity of the steel will easily hold everything where it ought to be.

FOOTNOTE: (Added by JAHansen, Mike’s wife) – Coming into the pole building business over a dozen years ago, knowing absolutely nothing about lumber, steel and the like, I can certainly identify with the skeptical client.  When you haven’t experienced the ease of building with lumber, 1-1/2” sounds pretty small to “hit” with a screw!

However, I can testify as a true novice at building, Mike’s words are straight as an arrow.  I’ve personally assisted on half a dozen buildings over the past years, and I can say almost every time there was a purlin or girt that looked like the screws were going to “miss” – especially on the wall girts where the weight of the wood sometimes caused the center to droop down an inch or more.  The holes near the ends were not a question for putting the screws into the wood. Because they are near the ends, the holes were “right on”.  We made sure on the center of each purlin or girt to use a block of wood as a support (wall girts) or in case of the roof purlins a “lever” to push the center into alignment.  It’s much easier than it sounds, and yes, the screws were dead on.

Thousands of pole buildings have been built, with no leaking roofs.  That should be solid proof, but if you still have doubts – go watch a pole building being constructed.  Seeing is believing.