Tag Archives: Simpson

NEW Hansen Pole Buildings Connections

NEW Hansen Pole Buildings Connections

For decades wood-to-wood connections for post-frame building construction have been with nails. Usually lots of nails, or (for non-engineered construction) not nearly enough.

Hansen Pole Buildings’ engineers have always specified 10d common hot-dipped galvanized nails for connecting 1-1/2” thick wood members to other framing members. Great part for strength, yet difficult to source.

Let’s take a look at strength characteristics of popular nails.

First (from 2018 NDS Table 11.3.3) if building with green lumber (over 19% moisture content), nails with a diameter of under ¼” have a 30% reduction in lateral strength and a 75% reduction (no reduction for post-frame ring shank nails) in withdrawal values! This would include driving through a dry 2x member into a solid-sawn column. A convincing argument for use of dry framing lumber and glu-laminated columns.

Lateral loads (shear) attaching a 1-1/2 inch thick member, both members of same species (from NDS)

10D commons / 20D box / 16d sinkers SYP 128# Dfir 118#

Pole barn ring shank nails (0.177” diameter) SYP 178# Dfir 163#

Withdrawal values (2018 NDS Table 12.2C) in pounds per inch of penetration into main member

Same nails as above SYP 46# HemFir 25#

Pole barn ring shank nails (with a 0.177” diameter), regardless of length, are limited by head pull-through values. With a 3/8” head maximum value is 191# (2018 NDS Table 12.2F). With a withdrawal value of 96# per inch in SYP, when attaching a 1-1/2”, any nail length over 3-1/2” is not adding to connection serviceability.

Simpson Strong-Tie SDWS16300 screws have a values with SYP of 229# in lateral loads and a withdrawal value of 192# per inch.

For attaching a 1-1/2” SYP member to another SYP member, SDWS screws are 179% stronger laterally loaded. For withdrawal (example being an externally mounted wall girt to a column), previously using a 10d common nail through a girt, into a Hem-Fir column would have been 25# x 1.5” x 0.25 = 9.375# of resistance. A SDWS screw into a SYP glu-lam 192# x 1.4” = 268.8#.

Hands down SDWS screws are superior and result in far fewer fasteners being needed, resulting in quicker installations.

Added benefit, have a board not quite where you want it? Much easier to back a screw out, than to pull a nail!

All NEW Hansen Pole Buildings now include SDWS16300 screws for attaching 1-1/2 inch (2x) members!

Call 1.866.200.9657 TODAY to participate in “The Ultimate Post-Frame Building Experience”.

And, don’t forget to watch for our next article

Simpson Strong-Drive SDWS Timber Screw

Simpson Strong-Drive® SDWS Timber Screw

In yesterday’s article I discussed attachment of roof trusses in post frame building construction. In most cases, Hansen Pole Buildings utilizes Simpson Strong-Drive® SDWS Timber screws.
It was more than twenty years ago Simpson Strong-Tie changed fastening world with introduction of a heavy-duty structural connector screw used in wood construction as an alternative to bolts. This screw, SDS or Strong-Drive® screw, was first screw of its kind able to be installed without predrilling and get loads comparable to bolts.

Simpson Strong-Drive® SDWS Timber screws have been newly redesigned for faster starts and less torque while driving.

They are designed to provide an easy-to-install, high-strength alternative to through-bolting and traditional lag screws. Strong-Drive® SDWS Timber screw proves ideal for both contractors and do-it-yourselfer alike. Code listed under AAPMO USE ER-192 it meets 2012 and 2015 IRC® (International Residential Code) and IBC® (International Building Code) requirements for several common wood framing and engineered-wood applications.

Photo: Simpson SDWS – Simpson Strong-Tie

A new patented point called SawTooth™ improves SDWS performance in two key respects. First it grabs wood, helping screw start fast and drive quickly. Occasionally, an installer runs into a piece of wood harder than others or engineered wood with a hard surface. When a hard surface condition becomes encountered, most screw points will spin around upon surface, grinding away wood fibers until one thread can finally catch and begin to cut in. Simpson designed this SawTooth™ point with a sharp angle and serrated threads to penetrate wood quickly. Threads begin to work right away, pulling screw in faster without frustration of waiting for point to scrape open a hole.

A bold thread design provides superior holding power. Under-head nibs offer greater control when seating screw head. Large low-profile washer head provides maximum bearing area (3/4” head diameter). All SDWS screw heads have a size identifier, making inspections easy. 6-lobe T-40 drive reduces driver-bit cam-outs, resulting in easier installations and longer bit life.

A second performance enhancement made to SDWS screws was to lower driving torque. Let’s face it, some of these screws are long, and you don’t want to have to fight to keep from being thrown by a drill. SawTooth™ point has a cutting knurl built into screw point. This helps open a hole in wood to receive threaded length of screw all while it’s being pulled in by threads. Having a thread top knurl helps reduce shank friction. Result – a screw driving with less wear and tear upon installer, drill motor or drill battery.

Double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making it suitable for certain exterior and preservative treated wood applications.

Watch the video here: https://www.youtube.com/watch?v=VpZmjgz2ckE

Simpson Strong Tie

I believe in the use of engineered connectors, wherever they can be prudently used in post frame (pole building construction). The average consumer who has visited a lumber yard, or a big-box home improvement center has probably seen many of them, but may not have given them more than a passing thought.

About two decades ago, when I was constructing pole buildings, one of our clients called us after a freakishly high wind storm (significantly higher than the design Code required wind load, at the timSimpson Strongtie H1 Hangere, of 70 miles per hour) had plowed through their building. This particular building had 2×6 roof purlins on edge, cantilevered over the endwall roof truss, to support the end overhang. The wind literally tore the purlins off the end truss, and flipped the first bay of the roof upside down onto the second bay!

In doing forensic analysis, after the wind died down of course, we determined the connection of the purlins to the end truss with toenails was adequate to have withstood a Code wind load, but not the wind speeds which had attacked the building. The solution for the repair, as well as for future building designs was to utilize a Simpson H-1 bracket to attach overhanging roof purlins to end trusses.

Typical Hansen Pole Buildings utilize many engineered steel connectors manufactured by Simpson.  Most typically they include joist hangers to attach roof purlins and bottom chord bracing to interior trusses and strap hangers to attach X bracing to trusses as well as end trusses to columns in high wind load applications.

There is an interesting history to the development of Simpson brackets, which I had been unaware of:

“The Simpson Family has been in the San Francisco Bay Area building community since 1914, but it wasn’t until the mid-1950s that they launched the business that would become a world leader in their industry. And it all really began with a visit from a neighbor.

“The doorbell rang one Sunday night in 1956,” recalled Barclay Simpson, who took over a window screen business from his father in 1947. Outside was a neighbor who was looking to make structural connectors for the ends of 2x4s for a flat roof. Could Simpson help him out? “I said, ‘Of course’ and then tried to figure out whether I could.”

It was that request for a joist hanger that led to the creation of Simpson Strong-Tie, a global company with more than $550 million in sales worldwide (2010), more than 1,800 employees, and nine U.S. and 10 international manufacturing locations. As a publicly traded company, Simpson Manufacturing Co. has had exceptional performance records since the company’s 1994 IPO. As a result, it has consistently commanded the respect of industry analysts for its market leadership, strong fiscal management, and innovative approach to growth.”

My experience is, if an engineered steel connector exists, Simpson makes it – and if it doesn’t exist, their engineering team will find a solution!