Tag Archives: toe-nailing

Avoiding Being Driven Crazy With Barndominium Questions Part II

Part II of a two part series. If you didn’t see Part I, go back one day.

Mike’s answers are in italics.

 In each house at ends of the “L” layout, I plan to have 1/3 open plan at two stories, for our great room, with nice windows for great views.

The other 2/3 areas will have 2 bedrooms and maybe a sitting area on the second floor.

  • Do  really need 6” * 6” poles in this area for the 2nd floor?
  • I was planning on building the upstairs like you do in a stick built house which would be use the 1st floor wall as load supporting, use 12” floor joists and  add a beam where needed and then use steel adjustable poles. (Cover poles later)
  • Is this OK to do?
  • Would the steel poles need to be on thicker concrete?
  • Would the 1st floor walls that will load support the 2nd floor need to be on thicker concrete?
  • You are free to say, “Greg if you had a decent floor plan, we should add a few poles, as it would be so much stronger, better, and other”.
  • Thoughts? Mike: Personally I would clearspan your second floor using prefabrciated wood floor trusses. There would be supported by LVL beams attached to your perimeter columns. This allows for walls to be placed anywhere without having to create bearing walls or have interior columns. All mechanicals can then be run through this floor truss system. If you were to approach your second floor as if it was traditional stick frame – you would then be faced with how to support it at exterior walls, since they are horizontally girted. Any bearing walls would have to have thicker concrete below and adjustable steel pole locations would probably require some sort of concrete pier (or at least slab being thicker and perhaps requiring some extra rebar). If using adjustable steel poles, I would want them to at least be wrapped with two layers of 5/8″ Type X sheetrock so in event of a fire they would not lose their temper, deform and collapse. 

Wall Girt System questions:

  • If the posts are 6” * 6” what width are the horizontal girt boards?  Are they 2” * 6” *  X’ or 2” * 8 “ * X’? Mike: For glulams of 2×6 you would have 2×8 girts, for 2×8 columns, 2×10 girts. These will project 1-1/2″ outside of your perimeter building columns.
  • If they are the 2 * 8’s, is there a little board you would put on the post, between the post and the outside metal? (This little stuff drives me crazy too!) Mike: Blocking would be placed on column exterior faces, aligned with wall girts to provide a continuous line for attaching steel siding with screws.
  • Are the vertical spacer boards nailed to the side of the post as shown on the attachment, so horizontal bookshelf girts can be nailed vertically into the spacer to avoid toe-nailing all of the girt boards? Mike: Bookshelf girts will be supported at each end with solid blocking against columns – no toe-nailing of girts to columns.

Does the lowest board on the posts, (Grade Board?), does it actually contact the dirt floor before pouring the floor? Mike: Bottom of pressure preservative treated grade board/splash plank is set at grade, so it is in contact with ground.

So the board will have 4” – 5” of cement contact? Mike: Top of your concrete slab would be 3-1/2 inches above bottom of splash plank.

How far does the siding cover the lowest board? Mike: Bottom edge of steel base trim drip leg will be at four inches above bottom of splash plank. This allows for any exterior concrete (walkways, approaches, door landings) to be poured against treated splash plank rather than against steel siding or trims.

Do you ever use a composite board for the grade board? Mike: Splash planks are used to transfer wind shear loads from siding to columns and into the ground. Composites are not structural and do not have an ability to transfer these loads.

Sorry for all the dumb questions. Mike: Only a question not asked would be considered as being dumb.

I appreciate all the effort from Hansen Pole Buildings.


Hangers & Toenailing

As the Nail Turns….

Every once in a while I write something which “touches a nerve” for someone.

Here is an, “Ask The Pole Barn Guru” exchange which got an engineer entertained:


And here is the feedback:

“You are very knowledgeable on almost every topic I read, but from one PE to another I am sad to read this post from you.  The toenails that “Novice” is inquiring about are a requirement in numerous hangers from Simpson, they are called double-shear nails.  For you to promote the use of the 1 1/2″ hanger nails amazes me.  The three particular hangers you call out do not need the toenails, but there are several issues with those hangers, if you are using 1 1/2″ nails you have to take a severe penalty to the load values listed, as well as the fact that those hangers do not offer the best solution.  If there is one thing that makes me cringe on projects is improper fasteners, and to see you promoting it amazes me.  I sincerely hope you write a new article on the matter.”

To begin with – let me say I am highly flattered for a PE (Registered Professional Engineer) to assume I am also a PE. My training is in architecture and while I am structurally highly versed in post frame design, I would be remiss if I did not make it perfectly clear to my readers …..(disclaimer time – drum roll)…..

I am not a Registered Design Professional (RDP). Any recommendations I make, are based upon my educational training, as well as over three decades of actual experience in the prefabricated metal connector plated wood truss industry and the post frame industry. My advice has always been – and always will be – to consult with a RDP prior to taking any structural course of action.

While “novice” may have indeed been concerned about double-shear nailing, I am more inclined to believe the nails into the hangers on decks viewed by novice were not.


Engineered hangers are typically selected due to ability to carry the required loads, ease of installation and price.

Using (6)-10d common nails into the header and (4)-10d x 1-1/2” nails into the joist a Simpson® LU26 hanger will carry 700# of floor load, 795# of roof at a 15% increase for Duration of Load, or 565# of uplift. All of these values are for use with DF-L (Douglas-Fir/Larch) lumber.

A double-shear alternative to the LU26 would be the LUS26, with (4) 10d nails into both the header and the joist. The comparative values are 865# / 990# and 1165# respectively.

All of these values are based upon a minimum nail penetration into the side member (the piece of the nail is being driven into) of 12 times the diameter of the nail. In the case of a 10d common (0.148 inch diameter) the nail must extend 1.776 of an inch into the “holding” member. Where a 1-1/2” long 10d common is used, the above values would need to be decreased by multiplying by 0.845. Popular framing lumber species such as SPF have a lower specific gravity and the values much be further reduced by multiplying by 0.86.

Mind numb yet? Just wait…..it gets better!

So, what kind of loads are going to be placed on either of these example joist hangers? Either of them will support either a 2×6 or a 2×8. For a 2×8 #2 DFir, placed on edge as a roof purlin and spanning 12’, spaced every 24”, will support a combined live and dead load of roughly 43.4 psf (pounds per square foot). The reaction at each end of the purlin would be 520.8#. The LU26 above supports 990 X .845 X .86 (for nailing into SPF) or 719.4# using all 10d x 1-1/2” nails.

Either hanger is going to adequately carry the majority of loads placed upon it in typical pole building construction (of course every specific case should always be verified by a RDP).

Simpson HangerEase of installation….according to Simpson Strong-Tie, the LU26 is virtually tied with the LUS26 for ease of installation.

Cost….the $64,000 question…..Simpson’s catalog online has a list price of $0.88 for the LU26 and $1.17 for the LU26. For most installations the 33% increase in cost, does not justify the unneeded 24% extra strength.

Back to the original posting which began this brouhaha…..Eric’s self-storage building has a design where roof purlins are hung into the side of a single 2x rafter, this design solution negates the ability to utilize a nail into the rafter of longer than 1-1/2”.

A typical Hansen Pole Building kit package utilizes a two-ply ganged wood truss, which is three inches thick. Our installation instructions for Simpson LU series hangers are to attach them to the double truss with 10d common x 3 inch long nails, therefore getting full value from the length of the fastener.

My summary to the responding PE…..

Due to cost, it is unlikely “Novice” has viewed many installations using Simpson JUS series hangers. I still believe the great majority of any splitting he has seen in deck installations is due to improper nailing, or the particular species of wood as it is being used.

For this particular set of circumstances the “severe” penalty of being able to utilize only 84.5% of the tabulated strength does not jeopardize the safety of the completed structure.

While there may be “better” design solutions, the Simpson LU series hangers are adequate for the loads being imposed, as well as less costly than other alternatives.

I am in total agreement about the use of proper fasteners – there are a plethora of cases of building failures of all types due to inadequate or improper fasteners – from backyard sheds to high rises.

When in doubt (which will be in most situations) consult with an RDP for an adequate design solution or solutions to any sort of structural construction question. And be sure to have them sign and seal any plans or calculations done for you.

P.S. In case the average reader has not deduced, I am a firm believer in sound structural design done by an expert, not just doing it the same way it worked for Uncle Billy Bob’s second cousin’s friend’s neighbor.