Simpson Strong-Tie Archives

Masonry Reinforcement and Concrete Strengthening with Composites

Guest blogger Brad Erickson, Engineering Manager: Composite Strengthening Systems™ — Guest blogger Brad Erickson, Engineering Manager

This week’s post comes from Brad Erickson, who is the Engineering Manager for the Composite Strengthening Systems™ product line at our home office. Brad is a licensed civil and structural engineer in the State of California and has worked in the engineering field for more than 17 years. After graduating from Cal Poly, San Luis Obispo with a B.S. in Architectural Engineering, he worked for Watry Design, Inc. as an Associate Principal before coming to Simpson Strong-Tie. Brad is the Engineering Manager for Composite Strengthening Systems and his experience includes FRP design, masonry and both post-tensioned and conventional concrete design. While not at work, Brad enjoys spending time carting his three kids around to their competitive soccer games and practices.

Have you ever had a concrete or masonry design project where rebar was left out of a pour? Chances are, the answer is yes. Did you wish you could solve this problem by putting rebar on the outside of that element? That’s exactly what Simpson Strong-Tie Composite Strengthening Systems™ (CSS) can do for you and your project. In effect, composites act like external rebar for your concrete or masonry element. Composites can be used in similar configurations to rebar but are applied on the exterior surface of the element being strengthened.

The initial offering in our CSS line is our fiber-reinforced polymer (FRP) product group. An FRP composite is created by taking carbon or glass fabric and saturating it with a two-part epoxy which, when cured, creates the composite. Together, the weight of the fabric and the number of layers in the composite determine how much strength it will add to your concrete or masonry element.

Another form of FRP composite is a precured carbon laminate. The carbon fibers are saturated in the manufacturing facility and are attached to the structure using CSS-EP epoxy paste and filler, an epoxy with a peanut butter–like consistency. We also carry paste profilers (pictured below) that help contractors apply the proper amount of paste to a piece of precured laminate.

Of course, before any concrete or masonry reinforcement project can succeed, proper surface preparation is of the utmost importance. Without a good bond with the substrate, a composite will not be able to achieve the intended performance. Concrete voids must be repaired, cracks must be injected and sealed, and any deteriorated rebar must be cleaned and coated. Prior to composite placement, the surface of the substrate must be prepared to CSP-3 (concrete surface profile) in accordance with ICRI Guideline No. 310.2. Grinding and blasting are the most common surface-preparation techniques.

The following are just a few applications where composites can be used for concrete and/or masonry retrofits. The orange arrows show the direction of the fibers in the fabric – in other words, the direction in which the composite provides tension reinforcement.

This is a summary of the basics of composites and their installation on strengthening projects. As composites are not yet in the design codes in the United States, the American Concrete Institute has produced 440.2R-08: Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures. This guide has numerous recommendations for using fiber-reinforced polymer systems to strengthen your concrete or masonry construction.

If you would like more information about FRP design, you can learn the best practices for fiber-reinforced polymer (FRP) strengthening design during a recorded webinar offered by Simpson Strong-Tie Professional Engineers. We look at FRP components, applications and installation. We also take you behind the scenes to share the evaluation process informing a flexural beam-strengthening design example and talk about the assistance and support Simpson Strong-Tie Engineering Services offers from initial project assessment to installation.

Learn more: Webinar – Introducing Fabric-Reinforced Cementitious Matrix (FRCM)

In this free webinar we dive into some very important considerations including the latest industry standards, material properties and key governing limits when designing with FRCM.

Continuing education credits will be offered for this webinar.
Participants can earn one professional development hour (PDH) or 0.1 continuing education unit (CEU).

For complete information regarding specific products suitable to your unique situation or condition, please visit strongtie.com/rps or call your local Simpson Strong-Tie RPS specialist.

Overcoming Adhesive Anchor Orientation Challenges with the Piston Plug Adhesive Delivery System

Modern code-listed adhesive anchors offer high-strength connection solutions for a variety of applications. However, as in all construction projects, good product performance requires proper selection and installation. In this blog post, we will discuss the challenge of installation orientation and an accessory that can help installers more easily make proper adhesive anchor installations—the piston plug adhesive delivery system.

ACI 318-11 Appendix D (Anchoring to Concrete) calculations use a uniform bond stress model to calculate an adhesive anchor’s resistance to bond failure. According to this theory, an adhesive anchor is assumed to transfer applied loads into the concrete base material uniformly along its effective embedment depth, h_ef. The equation for an anchor’s basic bond strength (expressed in pounds of force) is simply the adhesive formulation’s bond strength per unit area (λ * τ_cr) multiplied by the idealized cylindrical surface area of the insert that is in contact with the adhesive (π * d_a * h_ef):

N_ba = λ τ_cr π d_a h_ef (ACI 318-11, Eq. D-22)

Although the model is a simplification of reality, the mathematical expression represents the core assumption that the adhesive is able to transfer stress completely along the entire depth of the anchorage. This is a key requirement in installation: Anchoring adhesives must be installed such that air entrapment and significant voids are prevented.

Downward installations (Figure 1) have historically presented relatively few challenges for adhesive injection in this regard. In such applications, gravity is helpful; the adhesive naturally flows to the bottom of the drilled hole while being dispensed from the cartridge through a static mixing nozzle. The installer maintains the open end of the nozzle below the free surface of the adhesive until the drilled hole is filled to the desired level. For deep holes, extension tubing is affixed to the open end of the nozzle to increase reach. This procedure avoids entrapping air bubbles in the adhesive material.

Downward adhesive installation in concrete. — Figure 1 – Downward installation orientation

Installations into horizontal, upwardly inclined or overhead drilled holes (Figure 2) require more care on the part of adhesive anchor installers. Although the installation principle to avoid entrapping air is similar for these orientations, a key difference is that gravity does not help to keep the adhesive towards the “bottom” (deepest point) of the drilled hole. At worst, it can work against the installer when ambient temperatures may cause the adhesive to run out of the hole during injection. These adhesive anchor installations can be more difficult for an untrained installer and can slow the rate of work. This is one of the reasons that ACI 318-11 Section D.9.2.4 requires continuous special inspection of adhesive anchor installations in these three orientations when the application is also intended to resist sustained loads.

Figure 2 – Overhead, upwardly inclined and horizontal installation orientations (Source: ACI 318-11, Section RD.1) — Figure 2 – Overhead, upwardly inclined and horizontal installation orientations
(Source: ACI 318-11, Section RD.1)

To aid the installer, Simpson Strong-Tie offers a piston plug adhesive delivery system (Figure 3). Consisting of pre-packaged flexible tubing, piston plugs and an adhesive retaining cap, this system allows installers to more easily and consistently make high-quality installations while completing their work efficiently. The installation sequence is provided in Figure 4.

The system consists of three components:

Piston plug – The key component of the system, it is slightly smaller in diameter than the drilled hole. As the adhesive is dispensed into the drilled hole, the piston plug is displaced out of the hole by the advancing volume of the injected adhesive. The displacement creates a more positive feel for the installer to know where the free surface of the adhesive is.

Flexible tubing – For use with the piston plug to facilitate injection at the deepest point of the drilled hole.
Adhesive retaining cap – Provided to prevent adhesive material from flowing out of the drilled hole after dispensing and to provide a centering mechanism for the insert. For heavy inserts in overhead conditions, other means must be provided to carry the weight of the insert and prevent it from falling or becoming dislodged from the hole before the adhesive has fully cured.

What do you think about the piston plug adhesive delivery system? Let us know by posting a comment below.

Seismic Bracing Requirements for Nonstructural Components

Have you ever been at home during an earthquake and the lights turned off due to a loss of power? Imagine what it would be like to be in a hospital on an operating table during an earthquake or for a ceiling to fall on you while you are lying on your hospital bed.

Wood-framed Deck Guard Post Resources and Residential Details

A deck and porch study reported that 33% of deck failure-related injuries over the 5-year study period were attributed to guard or railing failures. While the importance of a deck guard is widely known, there was a significant omission from my May 2014 post on Wood-framed Deck Design Resources for Engineers regarding the design of deck guards.

A good starting point for information about wood-framed guard posts is a two-part article published in the October 2014 and January 2015 issues of Civil + Structural Engineer magazine. “Building Strong Guards, Part 1” provides an overview of typical wood-framed decks, the related code requirements and several examples that aim to demonstrate code-compliance through an analysis approach. The article discusses the difficulties in making an adequate connection at the bottom of a guard post, which involve countering the moment generated by the live load being applied at the top of the post. Other connections in a typical guard are not as difficult to design through analysis. This is due to common component geometries resulting in the rails and balusters/in-fill being simple-supported rather than cantilevered. “Building Strong Guards, Part 2” provides information on the testing approach to demonstrate code-compliance. Information about code requirements and testing criteria are included in the article as well.

Research and commentary from Virginia Tech on the performance of several tested guard post details for residential applications (36” guard height above decking) is featured in an article titled “Tested Guardrail Post Connections for Residential Decks” in the July 2007 issue of Structure magazine. Research showed that the common construction practice of attaching a 4×4 guard post to a 2x band joist with either ½” diameter lag screws or bolts, fell significantly below the 500 pound horizontal load target due to inadequate load transfer from the band joist into the surrounding deck floor framing. Ultimately, the research found that anchoring the post with a holdown installed horizontally provided enough leverage to meet the target load. The article also discussed the importance of testing to 500 pounds (which provides a safety factor of 2.5 over the 200-pound code live load), and the testing with a horizontal outward load to represent the worst-case safety scenario of a person falling away from the deck surface.

Simpson Strong-Tie has tested several connection options for a guard post at the typical 36” height, subjected to a horizontal outward load. Holdown solutions are included in our T-GRDRLPST10 technical bulletin. In response to recent industry interest, guard post details utilizing blocking and Strong-Drive® SDWS TIMBER screws have been developed (see picture below for a test view) and recently released in the engineering letter L-F-SDWSGRD15. The number of screws and the blocking shown are a reflection of the issue previously identified by the Virginia Tech researchers – an adequate load path must be provided to have sufficient support.

SDWS Detail C: Interior Post on Rim Joist between Joists, at 500-Pound Horizontal Test Target Load

Have you found any other resources that have been helpful in your guard post designs? Let us know by posting a comment.

24th Short Course on CFS Structures:
October 27-29 in St. Louis

This three-day course is for engineers who have limited or no experience designing with cold-formed steel (CFS), as well as those with experience who would like to expand their knowledge of cold-formed steel structural design. Lectures will be given by industry-recognized experts Roger LaBoube, Ph.D., P.E., and Sutton Stephens, Ph.D., P.E., S.E. The course is based on the 2012 AISI North American Specification for the Design of Cold-Formed Steel Structural Members and the 2012 North American Standards for Cold-Formed Steel Framing. Dr. Wei-Wen Yu’s book Cold-Formed Steel Design (4^th Edition) will be a reference text.

The course will address such topics as design of wall studs, floor joists, purlins, girts, decks and panels. It is eligible for 2.4 Continuing Education Units (CEUs). Advance registration is requested by October 10, 2015. For more information and to register, click here.

24th Short Course on CFS Structures: October 27-29 in St. Louis

Simpson Strong-Tie is sponsoring the 24^th Short Course on Cold-Formed Steel Structures hosted by the Wei-Wen Yu Center for Cold-Formed Steel Structures (CCFSS). The course will be held on October 27-29, 2015 at the Drury Plaza Hotel at the Arch in St. Louis, MO.
This three-day course is for engineers who have limited or no experience designing with cold-formed steel (CFS), as well as those with experience who would like to expand their knowledge of cold-formed steel structural design. Lectures will be given by industry-recognized experts Roger LaBoube, Ph.D., P.E., and Sutton Stephens, Ph.D., P.E., S.E. The course is based on the 2012 AISI North American Specification for the Design of Cold-Formed Steel Structural Members and the 2012 North American Standards for Cold-Formed Steel Framing. Dr. Wei-Wen Yu’s book Cold-Formed Steel Design (4^th Edition) will be a reference text.
The course will address such topics as design of wall studs, floor joists, purlins, girts, decks and panels. It is eligible for 2.4 Continuing Education Units (CEUs). Advance registration is requested by October 10, 2015. For more information and to register, click here.

BRACE FOR IMPACT! Bracing Design for Cold-Formed Steel Studs

While consideration of bracing is important for any structural element, this is especially true for thin, singly symmetric cold-formed steel (CFS) framing members such as wall studs. Without proper consideration of bracing, excessive buckling or even failure could occur. Bracing is required to resist buckling due to axial or out-of-plane lateral loads or a combination of the two.

There are two methods for bracing CFS studs as prescribed by the American Iron and Steel Institute (AISI) Committee on Framing Standards (COFS) S211 “North American Standard for Cold-Formed Steel Framing – Wall Stud Design” Section B1. One is sheathing braced design and the other is steel braced design.

Sheathing braced design has limitations, but it is a cost effective method of bracing studs since sheathing is typically attached to wall studs. This design method is based on an assumption that the sheathing connections to the stud are the bracing points and so it’s limited by the strength of the sheathing fastener to stud connection. Due to this limitation, the Designer has to use a steel braced design for most practical situations. AISI S211 prescribes a maximum nominal stud axial load for gypsum board sheathing with fasteners spaced no more than 12 inches on center. AISI S211 Section B1 and the Commentary discuss the design method and assumptions and demonstrate how to determine the sheathing bracing strength.

CFS Curtain Wall Stud Steel Clip and Bridging Bracing

Sheathing braced design requires that identical sheathing is used on each side of the wall stud, except the new AISI S240 standard Section B1.2.2.3 clarifies that for curtain wall studs it is permissible to have sheathing on one side and discrete bracing for the other flange not spaced further than 8 feet on center. The wall stud is connected to the top and bottom tracks or supporting members to provide lateral and torsional support and the construction drawings should note that the sheathing is a structural element. When the sheathing on either side is not identical, the Designer must assume the weaker of the two sheathings is attached to each side. In addition, the Designer is required to design the wall studs without the sheathing for the load combination 1.2D + (0.5L or 0.2S) + 0.2W as a consideration for construction loads of removed or ineffective sheathing. The Designer should neglect the rotational restraint of the sheathing when determining the wall stud flexural strength and is limited by the AISI S100 Section C5.1 interaction equations for designing a wall stud under combined axial and flexural loading.

Steel braced design may use the design methodology shown in AISI S211 or in AISI Committee on Specifications (COS) S100 “North American Specification for the Design of Cold-Formed Steel Structural Members.”

AISI S211 Table B1-1 Maximum Axial Nominal Load Limited by Gypsum Sheathing-to-Wall Stud Connection Capacity

Steel braced design is typically either non-proprietary or proprietary “clip and bridging” bracing, or “flat strap and blocking” bracing periodically spaced along the height of the wall stud.

CFS Wall Stud Steel U-Channel Bridging Bracing

CFS Wall Stud Steel Flat-Strap Bracing and Blocking Bracing

Proprietary wall bracing and wall stud design solutions can expedite design with load and stiffness tables and software as well as offer efficient, tested and code-listed solutions such as Simpson Strong-Tie wall stud bridging connectors.

Steel braced design is a more practical bracing method for several reasons. First, during construction, wall studs go unsheathed for many months, but are subjected to significant construction loads.This is especially true for load-bearing, mid-rise structures. Second, some sheathing products, including gypsum wallboard, can be easily damaged and rendered ineffective if subjected to water or moisture. Third, much higher bracing loads can be achieved using mechanical bracing. IBC Section 2211.4 permits Designers to design steel bracing for axially loaded studs using AISI S100 or S211. However, S100-07 requires the brace to be designed to resist not only 1% of the stud nominal axial compressive strength (S100-12 changes this to 1% of the required compressive axial strength), but also requires a certain brace stiffness. S211 requires the Designer to design the bracing for 2% of the stud design compression force, and it does not have a stiffness requirement. . AISI S100 is silent regarding combined loading, but S211 provides guidance. S211 requires that, for combined loading, the Designer designs for the combined brace force determined using S100 Section D3.2.1 for the flexural load in the stud and either S100 or S211 for the axial load. In addition, the bracing force for stud bracing is accumulative as stated by S211 Commentary section B3. As a result, the periodic anchorage of the bracing to the structure such as strongbacks or diagonal strap bracing is required.

CFS Wall Stud Diagonal Strap Steel Bracing Anchorage

Some benefits and challenges of steel clip and bridging bracing include:

Proprietary solutions, such as the Simpson Strong-Tie SUBH bridging connector, can significantly reduce installed cost since many situations require only one screw at each connection.
Unlike strap bracing, u-channel bracing can be installed from one side of the wall.
U-channel bracing does not create build-up that can make drywall finishing more difficult.
Extra coordination may be required to ensure that u-channel bridging does not interfere with plumbing and electrical services that run vertically in the stud bay.
Bracing for axial loaded studs requires periodic anchorage to the structure, such as using strongbacks or diagonal strap bracing.
Bracing of laterally loaded studs does not require periodic anchorage since the system is in equilibrium as torsion in the stud is resisted by bridging (e.g., U-channel) bending.

Some benefits and challenges of steel flat strap and blocking bracing include:

May be installed at other locations than stud punchout.
Required to be installed on both sides of wall.
Bumps out sheathing.
Bracing for axial loaded studs requires periodic anchorage to structure, such as using strongbacks or diagonal strap bracing (same load direction in stud flanges).
Bracing for laterally loaded studs requires design of periodic blocking or periodic anchorage to the structure (opposite load direction in stud flanges).

There are several good examples Designers may reference when designing CFS wall stud bracing. They include AISI D110 Cold-Formed Steel Framing Design Guide that may be purchased from www.cfsei.org, SEAOC Structural/Seismic Design Manual Volume 2 Example 3 that may be purchased from www.seaoc.org, and the Simpson Strong-Tie wall stud steel bracing design example on page 60 of the C-CFS-15 CFS catalog.

AISI S110 Cold-Formed Steel Framing Design Guide

SEAOC 2012 IBC Structural/Seismic Design Manual Volume 2

Cold-formed steel framing is a versatile construction material, but Designers need to carefully consider the bracing requirements of the AISI specification and wall stud design standard. What cold-formed steel wall bracing challenges have you encountered and what were your solutions?

Florida Product Approvals Made Simple

This year, the new 5^th Edition of the Florida Building Code was released and is now in effect statewide. First printed in 2002, the Florida Building Code was developed as part of Florida’s response to the destruction caused by Hurricane Andrew and other hurricanes in the state.

Another component, which I would like to take a closer look at in today’s post, is a separate Florida Product Approval system designed to be a single source for approval of construction products for manufacturers, Designers and code enforcers. This single system streamlines the previous approach of different procedures for product approval in different jurisdictions. While statewide approval is not required, many jurisdictions, manufacturers and specifiers prefer using the statewide system to the alternative, which is called local product approval. To ensure uniformity of the state system, Florida law compels local jurisdictions to accept state-approved products without requiring further testing and evaluation of other evidence, as long as the product is being used consistent with the conditions of its approval.

The rules of the Florida Product Approval system are in Florida Rule 61G20-3. Here is some basic information about Florida Product Approval.

The Florida Product Approval system is only available for “approval of products and systems, which comprise the building envelope and structural frame, for compliance with the structural requirements of the Florida Building Code.” So users will only find certain types of products approved there. However, if you work in areas where design for wind resistance is required, the Florida system can be a gold mine of information for tested, rated and evaluated products. Not only will you find products like Simpson Strong-Tie connectors with our ICC-ES and IAPMO UES evaluation reports, but thousands of other tested and rated windows, doors, shutters, roof covering materials and other products that don’t typically get evaluation reports from national entities. The specific categories of products covered under the Florida system are exterior doors, impact protective systems, panel walls, roofing, shutters, skylights, structural components and windows.

To protect consumers, a recent law passed in Florida states that a product may not be advertised, sold or marketed as offering protection from hurricanes, windstorms or wind-borne debris unless it has either State Product Approval or local product approval. Selling unapproved products in this way is considered a violation of the Florida Deceptive and Unfair Trade Practices Act.

Once a manufacturer understands the process for achieving a statewide approval, it is not difficult to achieve, but it can be expensive. The manufacturer must apply on the State of Florida Building Code Information System (BCIS) website at www.floridabuilding.org. To prove compliance with the code, the manufacturer must upload either a test report, a product certification from an approved certification entity, an evaluation report from a Florida Professional Engineer or Architect, or an evaluation report from an approved evaluation entity (ICC-ES, IAPMU UES, or Miami-Dade County Product Control). Then, the manufacturer must hire an independent validator to review the application to ensure it complies with the Product Approval Rule and that there are no clerical errors. Finally, once the validation is complete, staff from the Department of Business and Professional Regulation reviews the application. Depending on the method used to indicate code compliance, the application may be approved at that time or it may have to go through additional review by the Florida Building Commission.

Here are several ways to find out if a product is approved.

For Simpson Strong-Tie products, we maintain a page on www.strongtie.com that lists our Florida Product Approvals.
The Florida Department of Business and Professional Regulation maintains a page where users can search Product Approvals by categories such as manufacturer, category of product, product name, or other attributes such as impact resistance or design pressure.
A third-party group we work with has created a website called www.ApprovalZoom.com that lists various product evaluations and product approvals. In addition to listing Florida Product Approvals, they also list ICC-ES evaluation reports, Miami-Dade County Notices of Acceptance, Texas Department of Insurance Approvals, Los Angeles Department of Building Safety Approvals, AAMA certifications and Keystone certifications among others.

florida3 — Florida Department of Business and Professional Regulation Product Approvals search

The process for searching for approved products on the Florida BCIS is fairly simple.

Go to www.floridabuilding.org
On the menu on the left side of the page, click on Product Approval. Or, click this link to go directly to the search page.
On the Product Approval Menu, click on Find a Product or Application. Note that at this location you can also search for approved organizations such as certification agencies, evaluation entities, quality assurance entities, testing laboratories and validation entities.
Ensure the proper Code Version is shown. The current 2014 Florida Code is based on the 2012 International Codes.
At this point, several options can be searched. You can search for all approvals by a specific product manufacturer or a certain type of building component by searching Category and Subcategory, or if searching for a specific product, by entering the manufacturer’s name and the product name.

florida2 — Select the option highlighted in red

I hope you find the information contained in the Florida Product Approval system useful. Do you have other needs to find approved products?

Kids + Structural Engineering = The Tech Challenge!

This week’s post comes from Marlou Rodriguez who is an R&D Engineer at our home office. Prior to joining Simpson Strong-Tie, Marlou worked as a consulting engineer. His experience includes commercial, multi-family residential, curtain wall systems and the design of seismic bracing for non-structural components. Marlou is a licensed professional Civil and Structural Engineer in California, and too many other states to list. He received his bachelor’s degree in Architectural Engineering from Cal Poly San Luis Obispo. Here is Marlou’s post.Continue Reading

Design Examples for Steel Deck Diaphragm Calculator Web App

This week’s blog post was written by Neelima Tapata, R&D Engineer for Fastening Systems. She works in the development, testing and code approval of fasteners. She joined Simpson Strong-Tie in 2011, bringing 10 years of design experience in multi- and single-family residential structures in cold-formed steel and wood, curtain wall framing design, steel structures and concrete design. Neelima earned her bachelor’s degree in Civil Engineering from J.N.T.U in India and M.S. in Civil Engineering with a focus on Structural Engineering from Lamar University. She is a registered Professional Engineer in the State of California.

Like most engineers, you are probably often working against tight deadlines, on multiple projects and within short delivery times. If you have ever wished for a design tool that would make your work easier, we have an app for that. It’s a simple, quick and easy-to-use tool called the “Steel Deck Diaphragm Calculator” for designing steel deck diaphragms. This tool is so user friendly you can start using it in minutes without spending hours in training. This app can be found on our website, and you don’t need to install anything.

The Steel Deck Diaphragm Calculator has two parts to it: “Optimized Solutions” and “Diaphragm Capacity Tables.” Optimized Solutions is a Designer’s tool and it offers optimized design solutions based on cost and labor for a given shear and uplift. The app provides multiple solutions starting with the lowest cost option using different Simpson Strong-Tie® structural and side-lap fasteners. Calculations can be generated for any of the solutions and a submittal package can be created with the code reports, Factory Mutual Approval reports, fastener information, corrosion information, available fliers, and SDI DDM03 Appendix VII and Appendix IX that includes Simpson Strong-Tie fasteners. Currently, this tool can be used for designing with only Simpson Strong-Tie fasteners. We will be including weld options in this calculator very soon. Stay tuned!

The Diaphragm Capacity Tables calculator can be used to develop a table of diaphragm capacities based on the effects of combined shear and tension.

When “Optimized Solutions” is selected, the following input is requested:

Step 1: Building Information ̶ Enter general information about the project, like the project name, the length and width of the building to be designed along with spacing between the support members such as joist spacing, is entered.

Step 2: Steel Deck Information ̶ Select the type of the steel deck along with the fill type. You can select the panel width from the options or select “Any panel width” option for the program to design the panel width. Choose the deck thickness or select the “Optimize” option for the program to design the optimum deck thickness. You also have an option of editing the steel deck properties to accommodate proprietary decks that are within the limitations of SDI DDM03 Section 1.2. Select the joist steel (support) thickness that the deck material will be attached to. For some fasteners, the shear strength of the fastener is dependent on this support thickness.

Step 3: Load Information ̶ Enter the shear and uplift demand and select the load type as either “wind” or “seismic” and the design method as “ASD” or “LRFD.”

Step 4: Fastener Information ̶ This is the last step of input before designing. In the fastener information section, you have the option to choose a structural and side-lap fastener or let the program design the most cost-effective structural and side-lap options. This can be done by checking the “Provide optimized solutions” option. The default options in the program are usually the best choice. However, you can change or modify as needed for your project. You can also set the side-lap fastener range or leave it to the default of 0 to 12 fasteners.

Now let’s work on an example:

Design a roof deck for a length of L = 500 ft. and a width b = 300 ft. The roof deck is a WR (wide rib) type panel, with a panel width of 36″. The roof deck is supported by joists that are ¼” thick and spaced at 5 ft. on center. Design the diaphragm for wind loading using Allowable Stress Design method. The diaphragm should be designed for a diaphragm shear of 1200 plf. and a net uplift of 30 psf. The steel deck is ASTM A653 SS Grade 33 deck with F_u = 45 ksi.

This information is entered in the web app, as seen below.

After inputting all the information, click on the Calculate button. You will see the five best solutions sorted by lowest cost and least amount of labor. Then click on the Submittal Generator button. Upon pressing this button, a new column called “Solution” is added with an option button for each solution. You can select any of the solutions. Below the Submittal Generator button, you can select various Code Reports and Approvals and Notes and Information selections that you want included in the submittal. After selecting these items, click on the Generate Submittal button. Now a pdf package will be generated with all of your selections.

Below is the screen shot of the first page containing Table of Contents from the PDF copy generated. The PDF copy contains the solutions generated by the program, then the detailed calculations for the solution that is selected. In this case, as you can see in the screen shot above, detailed calculations for solution #1 are included with XLQ114T1224 structural screws; XU34S1016 side-lap screws; 36/9 structural pattern and with (10) side-lap fasteners; diaphragm shear strength of 1205 plf. and diaphragm shear stiffness of 91.786 kip/in. The detailed calculations are followed by IAPMO UES ER-326 code report and FM Approval report #3050714.

Below is another example of a roof deck to be designed for multiple zones.

Design a roof diaphragm that will be zoned into three different areas. Zoning is a good way to optimize the economy of the roof diaphragm. Below are the required diaphragm shears and uplift in the three zones.

Zone 1: Diaphragm shear = 1200 plf.; Net uplift = 30 psf.; Length and width of zone 1 = 300 ft. x 200 ft.
Joist spacing = 5 ft.

Zone 2: Diaphragm shear = 1400 plf.; Net uplift = 0 psf.; Length and width of zone 2 = 500 ft. x 200 ft.
Joist spacing = 5.5 ft.

Zone 3: Diaphragm shear = 1000 plf.; Net uplift = 25 psf.; Length and width of zone 3 = 300 ft. x 200 ft.
Joist spacing = 4.75 ft.

Refer to the example above for all other information not given.

To design for multiple zones first select the Multi-Zone Input button, which is below the Fastener Information section as shown below:

When you click on the Multi-Zone Input button, you can see a toggle button appearing above a few selections as shown below. The default for the toggle button is globalbutton , which means that this selection is same for all the zones. You can click on the toggle button to change to zonebutton . Then the selection below changes to a label and reads Zone Variable. After all the selections that need to be zone variables are selected, click the Add Zone button. Keep adding zones as needed. A maximum of five zones can be added. After creating the zones, add the information for each zone and click the Calculate button.

When the Calculate button is clicked, the results for each zone are listed. The five best solutions are listed for each of the zones as shown below.

Similar to previous example, select the Generate Submittal button to select the solutions to be included in the submittal generator. Select one solution for each zone and then check the items like the code reports or notes to be included in the submittal. Click Generate Submittal to create the submittal package.

See the screen shot below for the steps.

Now that you know how easy it is to design using our web app, use this app for your future projects. We welcome your feedback on features you find useful as well as your input on how we could make this program more useful to suit your needs. Let us know in the comments below.