Tag Archives: copper naphthenate solution

Post Frame Barndominium Exterior Wall

Post Frame Barndominium Exterior Wall Questions

Reader IAN in RIDGWAY writes:

“I am looking for help understanding a couple of exterior wall questions.  

  1. My county is enforcing the 2018 IECC for energy efficiency. In my region this requires R-20 cavity + R-5 exterior wall assembly.  From everything I’ve read, this means a continuous layer of 1″ rigid between the framing members and the metal siding.  Is this an accurate understanding in your mind?  Does the 1″ of rigid between framing and siding affect the integrity of the structure at all?  Are the fasteners that are shipped with your kits long enough to accommodate the 1″?
  1. We will be living in our pole building, which means we will need to meet minimum code standards for receptacles at the exterior walls.  I am under the impression that the poles must remain whole and are not designed to have a hole drilled through each for ease of pulling wire.  Am I correct here?  What is the suggested solution? Conduit everywhere below my slab?”

Mike the Pole Barn Guru responds:

Nice to see jurisdictions enforcing IECC (International Energy Conservation Code) requirements, as it will result in more energy efficient structures. In Ouray County, you are in Climate Zone 6B. This requires ceiling R-49, wood frame walls of R-20 plus R-5 (or R-13 plus R-10) where second value is continuous insulation and slab edges to have R-10 four feet deep.

According to Martin Holladay (Green Building Advisor editor) your continuous insulation is just as effective when installed on the interior of your wall framing. This is very important when it comes to fully engineered post frame construction. Properly engineered, post frame construction relies upon shear strength of steel skin to transfer wind loads through building planes to ground (https://www.hansenpolebuildings.com/2011/12/lateral-wind-loads/). Having rigid insulation between framing and siding would reduce or negate your siding’s shear strength and result in a less than satisfactory outcome. My recommendation would be to use a Weather Resistant Barrier on the outside of the framing, directly inside of steel siding. Fill insulation cavity with unfaced batts (preferably stone wool such a Roxul as it is not affected by moisture https://www.hansenpolebuildings.com/2013/03/roxul-insulation/) or BIBs (https://www.hansenpolebuildings.com/2011/11/bibs/), then a well sealed rigid insulation board between framing and interior finish. Done this way, your wall will ‘dry’ to the exterior, making your home’s HVAC system less responsible for reducing interior humidity levels.

Your wire pulling is far easier than you may have initially envisioned. 

Very little drilling, if any, will be needed for holes in order to run electrical wires. Wall framing (girts) extend or are placed so as to leave a 1-1/2 inch space between outside of wall columns and siding.

Think of a hole being drilled through as being an “open knot”. Lumber grading rules refer to these as being “Unsound or Loose Knots and Holes” due to any cause. Most structural framing – like wall girts and roof purlins or posts and timbers are graded as Number 2.

For practical purposes, a hole up to just less than ¼ of board face being drilled through will be within grade in #2 lumber. Example: 3-1/2” face of a 2×4 a hole up to 7/8” may be drilled through, as often as every two feet. Allowable hole sizes are reduced and spacing increased for higher grades of lumber. 

Any holes drilled through pressure preservative treated lumber or columns, especially near         grade, should be treated with a Copper Naphthenate solution. Copper Naphthenate is available as a brush-on (Cuprinol No. 10 Copper-Green® Wood Preserver          https://www.homedepot.com/p/Copper-Green-1-gal-Wood-Preservative-176223/300502829)

or spray-on(https://www.homedepot.com/p/Copper-Green-Wood-Preservative-14-fl-oz-  


How to Install Bookshelf Girts for Insulation

How to Install Bookshelf Girts for Insulation

Reader SEAN in CAMAS writes:

“Please help! I have plans for a 48x60x16 pole barn here in the NW. I helped build a pole barn when I was in my teens and I think mostly for my young back and ability to swing a hammer. However I am a bit lost with these new plans. They call for bookshelf girts.  I sent a photo of the plans showing the details and the cut away. I get that the boards are on their side between the posts with a 2×6 “holding it up” on both ends that is nailed to the posts. However it looks like they all protrude 1 3/4″ beyond the outside of the post based on the bottom PT board being laid on the outside of the post. This would make sense to keep the siding all hitting a level board all the way up. Any photos or explanation would help greatly.” 

Well Sean, you are finding a set of plans is only as good as installation instructions provided with them. Having thorough step-by-step instructions, such as those in Hansen Pole Buildings’ Construction Manual, can save countless hours of grief, wasted materials and doing and undoing work.

Here is an excerpt you can use:

Most Common Mistakes:

  1. Installing wall girts before framing roof and roofing. 
  2. Placing first girt bottom at a height other than 27-1/2” above grade.
  3. Girt end blocks cut to varying lengths.
  4. Setting girts to project beyond column outsides other than by 1-1/2”.

Cut girt blocks to 22-7/16” lengths from 2×4 material provided. First girt block bottom edge starts 5-1/2” above splash plank bottom. After the concrete floor has been poured, a 2×4 pressure treated base plate will be inserted between floor top and girt block bottoms.  Base plate is toe-nailed to the pressure treated column at each end (exception being if columns are attached to brackets), as well as anchored to the concrete floor two feet on center (using concrete nails or nails “shot” into concrete). Base plate inside edge will be even with the inside edge of the girts above. Base plate should be installed over a sill gasket and/or caulked to the concrete floor. When space between treated columns is less than 24”, there is no base plate.

See Figure 29-1

Figure 29-1 Toe-nailing Base plate


Any pressure preservative treated lumber cut edge or end should be treated with a Copper Naphthenate solution. Copper Naphthenate is available as a brush-on (Cuprinol No. 10 Copper-Green® Wood Preserver https://www.homedepot.com/p/Copper-Green-1-gal-Wood-Preservative-176223/300502829) or spray-on (https://www.homedepot.com/p/Copper-Green-Wood-Preservative-14-fl-oz-Aerosol-CopperSpr/100191444).

Girt blocks are placed so the block inside edge is flush with the wall girt inside edge. This may cause girts, as well as blocking, to extend past columns on inside, without adversely affecting interior finish applications such as gypsum wallboard. Nail girt block with (2) 10d common nails at each end (unless specified otherwise on building plans).  

In any event, the total nail number used to attach any girt block to a column should never be fewer than the nail number used to attach girt to block top.

Cut girt to fit snugly between columns, with “crown” out, resting on girt blocking at each end. Outside girt edge extends from columns outward 1-1/2”. See Figure 29-2

Figure 29-2 Commercial Bookshelf Girts For Insulation

Nail each girt end securely into girt block tops below, with two 10d common nails minimum. Repeat for each bay around building.

Where two adjacent wall columns are 2’ or less in between, 2×4 exterior (barn style) girts will be provided to nail on outside column faces, as insulation batts will fill space remaining.

Nail 2x blocking material to exterior column faces in line with girts.  This a good way to use up cutoffs from bookshelf girts. See Figure 29-3

This blocking will serve as backing material for any screws falling in this area.

Figure 29-3: Commercial Bookshelf Girts 2x Blocking

Install 2×4 inverted “L” sidewall drywall backing using 2-10d common toe-nails through “L” vertical member into columns. See Figure 29-4

4” shown in Figure 29-4 is for 2×6 girts; for 2×8 girts, it will be 5-3/4”.

 Figure 29-4: L Sidewall Drywall Backing

For buildings without ceiling joists, install 2×4 inverted “L” endwall drywall backing using 2-10d commons toe-nailed through “L” vertical member into columns.

  See Figure 29-5

Figure 29-5:  “L” Endwall Drywall Backing

This should give you a good start. Good luck and let me know how it all turns out. Pictures appreciated!