Delegated Design in Specs for Glazing Systems

We've been asked to review several engineering company’s calculation packages and found engineers
stamping calculations that don’t meet specifications and code requirements.  Please check your calculation packages to be sure.

We found:

1. DL of the frame was not taken into consideration (flexure/axial load interaction) Typical C-Beam Calculations did not include axial load interaction with flexure required by the Aluminum Design Manual
2. Corner location analysis (75% WL acting simultaneously). Bite loss or movement into glazing pocket was not checked. Analysis of corners for 45 degree orthogonal loading was not considered as required by ASCE 7. Important for bite loss at the glazing pocket.
3. No Jam/perimeter mullion deflections to check caulking requirements. Deflections at Jamb perimeter joints were not checked for appropriate joint design. Important for preventing leaks at curtain wall interface to the structure.
4. LL movement was not taken into consideration at all.  Building structural live load movement and system thermal expansion was not accounted for in joint design, splices and glazing pockets. This is required by contract specifications as part of the delegated design.
5. Analysis of local buckling modes and lateral torsional analysis was omitted but is required by the Aluminum Design Manual.

“If undone, you are buying calculations half done                                                and not according to code requirements.”

It may be tempting to overlook it and we understand some contractors will simply say, "It's not worth the effort."  Just keep in mind that these calculations are a part of the “delegated design” required by contract documents. If left undone, glazing contractors, general contractors, AEs and the building owners are buying a design half done and not according to code requirements.

“Half done calculations may result in glass breakage, joint leakage, system failure or other liability.”

Half done calculations may result in damage such as glass breakage, joint leakage, system failure or other liability that quality service providers choose to steer clear of.

Let’s work together to design systems fast, affordable and correct.

Info@ JEIstructural.com 

816-505- 0987

FAST | CLEAR | FRIENDLY | RIGHT

Info@ JEIstructural.com 

816-505- 0987

Point Supported Glass Guardrail Engineering & Glass Rail Design

Glass Rail Design

glass balustrade design, glass rail detail, glass handrail engineering 

Cutting Holes In Glass Engineering Tips

Glass Rail Design

glass balustrade design, glass rail detail, glass handrail engineering 

JEI Structural Engineering

816-505-0987

Info@ JEIstructural.com

Vitrum 2017 JEI Structural Engineering - Introduction

Cladding Design

Cladding design, cladding detail, cladding drawings and more. 

We're cladding engineer & design, cladding engineering working on composite panel design, metal panel detail, and metal panel design.

Universities do not teach aluminum panel design, aluminum panel detail, composite panel detail, composite panel design, or metal panel design.

Finding an experienced cladding engineer in aluminum consulting, or aluminum detail working as an aluminum engineer isn't easy.   JEI Structural Engineering is to "go to" for glazing contractors, manufacturer and architects.

New Patent Curtain Wall Anchor - Test Project 1

Curtain Wall Engineer - New Patented Curtain Wall Anchor.  

Curtain wall design, curtain wall details, curtain wall detail, glass curtain wall details

Having a curtain wall plan and curtain wall detail are the first step to curtain wall engineering.  Glazing contractors need curtain wall drawings or a curtain wall drawing. A curtain wall engineer with curtain wall calculations can offer curtain wall consulting.   

At JEI Structural Engineering, our team is innovative and solves problems.  We've invented and patented a new curtain wall anchor system that is available for sell or license now.

Glass Canopy Engineering

Glass handrail engineering, glass wall engineering, glass calculations, glazing design, glazier design, glazing calculations, structural glazing design, and window blast engineering.

Contact JEI Structural Engineering at 816-505-0987.

Temporary Set Up To Hold Glass In Place

Shop Drawings & Details

We work on curtain wall details, curtain wall detail, facade detail, glass wall detail, and structural glazing details.  Facade detail, glass balustrade detail, glass wall detail, glass detail, glass floor detail.  Cladding detail, structural glazing detail, glass canopy detail.

Glazing detail, glass plan, glass wall plan, window wall detail.  JEI Structural Engineering offers storefront detail, curtain wall drawings.  Facade drawings, metal panel detail, glass rail detail, glass stair detail, glass staircase detail.  Skylight drawing, storefront drawings, aluminum detail, and aluminum panel detail. Our team are experts in cladding drawings, compost panel detail, glass floor drawing, glass wall drawing, glazing drawings, glazing plan, skylight drawings, glass curtain wall detail, glass curtain wall details, window mullion details and more.

Curtain Wall - Structurally Sealed Vertical Example

Curtain Wall - Structurally Sealed Vertical Example

JEI Structural Engineers show an example of structural sealant use in curtain wall design. Our goal is to help educate those new to our industry on common terms and examples from live projects so jobs run smoothly.

Glass and Glazing Sealants are prevalent.

Structural glazing systems, in their simplest form, are types of curtain wall systems consisting of glass that is bonded or anchored back to a structure without the use of continuously gasketed aluminum pressure plates or caps.

Structurally glazed systems create a greater transparency than traditional captured systems. There are less visual interruptions due to the lack of metal on the, creating a seamless, continuous glass look.   

The main types are:

Stick-built structural glazing system 

Unitized structural glazing system  

Point supported glass systems 

www.JEIstructural.com

Glass Storefront Engineering & Glazing Challenges

Glass Storefront Install & Engineering Challenges

New Project Specs Require “Sealed Calculations” for storefronts.  (That’s engineering!)

Most manufacture Wind load charts DO NOT fully account for updated code requirements.

In the past, there were loopholes that allowed engineers more flexibility than the current ADM 2015 requirements on open shapes.   This can mislead glazing project managers costing more steel, higher engineering & lost time.

Add to that, the issue of Building Movement, which is required by delegated design to consider.  

As you know, the impact of designing and installing a storefront wrong isn’t life threatening, so a few people overlook the issues entirely.  Preferring to bury their head in the sand.   The result is minor system failures that may cause water leaks or damage and sometimes require system replacement.   At worst, it’s a lawsuit.

At some point, all the codes will catch up to the new standards.     JEI Structural Engineering is ahead of the learning curve, developing:

·      Custom Wind Load Charts with lateral buckling checks, according to code.

·      Calculation and design methods that reduce steel.   

·      Pre-Design assist that Anticipates Building Movement at the storefront head.

At JEI, we realize glazing contractors want: speed of service, high quality communication and fair prices.   

Get us in the loop early and we’ll help spot potential obstacles and road blocks, freeing you to deliver the caliber of services a tradesman can be proud of.

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For a free quote, send construction documents to Info@JEIstructural.com  or Call 816-505-0987

www.JEIstructural.com 

Currently JEI Structural Engineering has PE’s in

AR, AL, CO, CT, DC, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, NE, NJ, NY, OH, OK, PA, SC, TN, TX, UT VA, WA, WV and growing.

If you need a  PE, please contact us to check updated licensing, certification and credentials.

Storefront design, storefront detail, storefront consulting, storefront drawing, and storefront drawings. 

Codes Changes Creating a Cladding Mess

If you’re a glazing contractor or a building envelop contractor; an estimator or project manager, you’ve probably tried to size your storefront and curtain wall members off of a wind design pressure.  

The wind design criteria are usually given on the contract structural drawings.   Sometimes design wind pressures for components and cladding are given as well.  However, the changes with the 2012 IBC have created much confusion regarding the actual design pressures to be used.

Many times the components and cladding pressures listed on the structural drawings are given in terms of “Ultimate strength design”, which is not used in any of the wind load charts given by manufactures.   Using these pressures will ultimately lead to overly conservative design.

Designers need to be able to calculate the allowable strength design loads from the information given off of the structural drawings.

If you have a question about what is on a structural drawing, give us a call.   

Stewart Jeske

816-734-8345

www.JEIstructural.com

 

Can you break me down the difference in Explosive Weight I and Explosive Weight II?

Explosive Weight I and Explosive Weight II?

Question

Can you break me down the difference in Explosive Weight I and Explosive Weight II?

 Answer

This is the criteria from the 2012 UFC:

Explosive weight I is associated with a larger weight of TNT for a van or truck bomb outside of the base perimeter.   Its based on the assumption that a vehicle bomb will not be able to penetrate the base perimeter and/or will be detected at the gate.  If we have a facility that is less than 200 feet from the base perimeter/fence, then we must consider explosive weight I in addition to explosive weight II and its pressure/impulse may govern over the explosive weight II.

Explosive weight II is associated with a smaller weight of TNT simulating a back-pack or smaller bomb that gets past the base gate.  The standoff for this explosive weight is no longer the 82 feet typical of the 2007 criteria.  Now it is based on the new conventional stand-offs that are listed in the tables based on construction type and load bearing/non-load bearing walls.  The actual stand-off must be used which is from the parking lot to the window/wall in question.

Hope this helps.  Please call if you have any questions.

Stewart P. Jeske, P.E.

JEI Structural - Glazing Systems Engineering

www.jeistructural.com