Bookshelf Girts aka Commercial Girts: What Are They?

Bookshelf Girts aka Commercial  Girts: What are they?

I do a lot of blogging, not because I enjoy it (which I do) but because I am always “listening” and learning.  And if there is anyone out there who I can help along the way, my fun increases exponentially.  I recently came across this posting on a Farm Forum:

Commercial Wall Girts

I am going to build a new shop building and wish to be able to finish the inside, insulation, sheeting, etc. I am in Minnesota, so it has to be fairly energy efficient. I saw some brief info on the “bookshelf method” in a pamphlet I picked up from a store. Looks like a super way to provide the desired structure on the inside of the wall surface to fasten sheeting to, and provide spaces for fiberglass batts laid in there horizontally. Very material efficient method, I believe. If anyone here has used this method, please share your experiences with it, pictures too if possible. Even if you have seen one built, like by a neighbor or friend, please speak up and share.
In case you do not recognize the method by the name I gave it (bookshelf), it is a technique which puts the wall girts between the posts, laid flat, typically 2×6’s, 24 inches on center vertically spaced (instead of the usual girt method which puts them on the outside of the posts). The pamphlet says they can be toe-nailed (?) or little nailers installed above and below them, for fastening to the posts. The pamphlet says wind loading is increased with the bookshelf method. The real attractive part of this method for me is that the 2×6 girt is available to the outside tin for fastening, then provides a 22.5 inch tall space for fiberglass bat (off the shelf size for between trusses on 24 inch center) and then is flush to the inside of the wall for interior wall sheeting fastening.

I’ve done several thousand pole buildings using the “bookshelf” or “commercial” girt method. I have two of them myself – in Northeastern WA, so have cold climate to contend with.

Use a commercial girt one size larger than the columns (2×8 on a 6×6 post, etc.), setting the commercial girt so 1-1/2″ hangs past the exterior face of the column. Wrap the framing with a well sealed high quality building wrap.

You will find this installation method compensates for any irregularities in the column dimensions and creates a deeper insulation cavity. Side benefits – electrical can be run around the outside of the columns, without the need to drill through them to run wires. On walls which are a multiple of 3′ in length, it also saves having to rip the edge of a panel off either the first or last sheet of steel on the wall.

In either case, block the ends of the bookshelf commercial girts solid against the columns with what is called “bearing blocks”.  Take 2×4’s or larger (depends upon engineering) which are cut 22-1/2” long to fit between the commercial girts and install them flat against the post on each side.  The wide face of the block should be flat against the column and lined up with the edge of the post (not sticking out past the column like the girts are).   Nail these girt support blocks to the columns with a minimum of (2)10d galvanized common nails at each end (higher wind loads may require more nails).  This type of nailing is quick and easy and provides a solid support for the commercial girt above it.  Toe-nailing is done by angling a nail upwards from the bottom (or downwards from the top) of the commercial girt, at a 45 degree angle trying to catch enough of the edge of the post as the nail goes through to the column to hold it there.  Toe-nailing is a very poor connection (is subject to lots of installation error).

For maximum cost effective R value, use BIBS insulation. I found it to be cost competitive with installed batt insulation, has a higher R value and completely fills all of the voids.

I fondly remember the gal who called me one day asking for “canning jar shelves”…you know like you did before for us.”  Checking our records, I quickly discovered we designed commercial girts on their first building.  They liked them so much – they wanted them again!

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15 thoughts on “Bookshelf Girts aka Commercial Girts: What Are They?

  1. Christopher Thomas

    Ditto above comment. Not only have I bookmarked your site, but I’ve also spent countless hours reading your thoroughly entertaining and enlightening blog as we narrow down our pole barn design! So much info to absorb, so little time. Thanks Guru for all you do for us pole barn newbies!

  2. The problem with this particular method is over the years they can sang slightly so unless you have something stiff to keep the boards from sagging in 30 40 years I’ll have a sag to them. I’ve only been doing it for 20 years or so but a lot of buildings that I have seen that I’ve had to go in and fix this is one of the problems that they have when i have to come in and fix them they tend To sag towards the middle they can come down to two 3in so I’ve never liked using that method personally

    1. Thank you for your input.

      The steel siding is all screwed off to each girts as well as the pressure preservative treated splash plank and the eave girt or soffit support which is a vertical member. In order for more than a small fraction of an inch of “sag” to occur, the siding would have to be buckling significantly. Granted I have only been involved in over 10,000 buildings with bookshelf girts personally and have never seen or had a report of one sagging, so it could be my experience is an exception to the rule. I know my two personal buildings with bookshelf girts show no downward deflection, but they are only 20-25 years old so it could be they are waiting for that 30-40 year time frame.

      If you can provide some documented proof of sag over time, I’d certainly appreciate you sharing it. Documents should include photos at time of installation, as well as a current photo showing the sag in relationship to a stringline.

      1. Hi, what are the benefits of commercial wall gerts over running gerts on the inside and outside of the post? Specifically in strength. Thanks! Hope to order my kit in February!!

  3. Hi there. I have received a quote from your company and am very impressed with it. I will be building once i get a good producing well dug. This fall I built a small bunk house on the property to try out winch boxes for setting the roof in sections. Worked absolutely fantastic. Doing most of the roof framing on the ground was very efficient and easy. We always use joist carriers and 4’ oc trusses up here in northeast ind. my question is that this is going to be my residence. So as far as longevity of the post. I be thought about pouring piers with wet set brackets to eliminate the chance of rot. Never been around these brackets. Would the post be stable enough to use my winch boxes for hoisting the two sets of trusses with purlins on. The use of the winch boxes are a game changer. Literally one person can set trusses. Suggestions or ideas? Thanks

    1. Winch boxes are the absolute bomb, aren’t they? You really don’t have to use truss carriers and trusses very four feet, there are other options which may prove to be easier to construct as well as less costly.

      I happen to live in a post frame home which has two stories plus a mezzanine. It is 44′ from grade to peak of roof. We used embedded posts and have full confidence in their ability to outlive us (and I plan on living for a long time). Keep in mind, I could have used any option I desired and our home has 8000 finished square feet and is probably worth well into seven figures.

      In the event you decide to go with piers and wet set brackets, they will be plenty stable for you to be able to use winch boxes to lift your roof.

      Best of success in the well digging department.

  4. Thanks for this great information. I have a post frame building with bookshelf girts and I’m hoping to finish the interior this summer. I need to add a few big window and an entry door. Do you have any details on how to best frame out a standard residential door and windows in this wall type?

  5. For taller buildings requiring 8-inch posts (8-inches in the tranvserse direction of the wall), how you handling bookshelf girts since a 2×8 is only 7 1/2″ and 2×10’s are very expensive?

    1. In the global scope of life and in most markets 2×10 really are not that much more than 2×8 (usually about 25% more on a board-by-board basis). 2×8 (by the way) only measure 7-1/4″ and 8″ posts measure 7-1/2″.

  6. Looking for your suggestions/input on using 2×10 bookshelf girts on 3ply post w/10’OC post spacing to act as both exterior and interior girts for attaching metal panels to both sides. Pricing for one 2×10 is well below the price for having to use twice as many 2×6 girts so I’m curious if there would be structural benefits to either.

    1. Assuming your 3 ply posts are 2×6, you can use 2×8 bookshelf girts. Structurally, your wall will be much stiffer between columns and there will be less deflection.


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