WHAT IS AN EJ?
 

An engineering judgment (EJ) is a drawing typically generated in PDF format by a firestop manufacturer for a jobsite-specific application. They are generally submitted to contractors, customers, architects, or MEP consultants. EJs are recommended as a solution when a jobsite condition deviates from a tested firestop system. When creating EJs, firestop manufacturers must adhere to certain guidelines which are defined by local official authorities. 

What is their purpose?

Contractors and customers frequently encounter unique firestop applications at construction jobsites that require various arrangements of penetrations through fire-rated assemblies or joints/curtain walls. These applications often deviate from tested and approved firestop systems. In such cases, customized solutions are provided as drawings for a single application or for an entire project. These drawings are based on a combination of multiple third-party approvals/certificates, internal test data, expertise and an understanding of the properties of different firestop products in certain conditions of application.

    
Pic 1: Example of an engineering judgement (EJ)
 
How are these drawings created? 
After an application description has been provided by the customer, engineering judgments are created by using the most relevant / closest third-party tested and approved systems (e.g. tested acc. to UL1479, ASTM E814. Qualified personnel creating the EJ may include a trained engineer of the firestop manufacturer.
 
Engineering judgments at Hilti 
Firestop systems are designed and installed to impede the passage of fire and smoke, with some systems designed to also restrict water and sound, through construction openings in fire-rated assemblies (walls and floors).
These systems are required by all Building Codes to be tested and rated as part of an assembly in accordance with different standards like ASTM E-814/UL 1479 for through penetration, ASTM E-1966/UL 2079 for construction joints & ASTM 2307 for curtain wall joint.

Presently, there are no particular guidelines around EJs in standards other than ASTM, but the use of EJs is widely accepted. The testing and rating process ensures that each specifically designed system will maintain or exceed the hourly fire rating, as tested, for which it was approved.

Characteristics of a well-regulated EJ regulation or guidance paper for evaluating engineering judgments 

• Uses tested systems in lieu of EJs when available 
• Issued only by qualified technical personnel 
• Based upon interpolations of previously tested and closest firestop systems
• Based on the expectation that the recommended firestop system will perform as designed if subjected to the appropriate firestop test standard for the required fire-rated time 
• Limited only to the specific conditions for which it was designed 
• Issued for a single construction project and is not transferable without review by the issuing entity
• Issued only in those locales where local codes permit their use as suitable for meeting building code requirements 

 
Basic EJ presentation requirements 

• Present in descriptive formal written form, with or without detailed drawings
• Indicate clearly that the recommended firestop system is an engineering judgement and NOT a listed system
• Identify job, contractor, non-standard conditions and required hourly rating
• Provide complete descriptions of all vital elements of the firestop system (i.e. type of assembly being penetrated, type of penetrant, size of opening, annular space requirements, etc.) 
• Include clear installation instructions for the firestop system
• Show date of issue and authorization signatures, as well as issuer’s name, address and telephone number 
• Reference the number of the tested system(s) the design is based on
• Must be prepared based on a single standard

As you can see, an EJ is an important and handy tool to deal with unique site conditions and help to ensure safety at the same time. It is also mandatory to use an EJ in case of deviations from already available tested systems. HILTI has dedicated resources to help our customers by providing EJs in a quick and efficient manner.
 
Steps to request an engineering judgment

1. Gather all required project and application information.
2. Login to www.hilti.com.ph if you already have an account. Register and complete the form if you don’t have an existing account.
3. Navigate to Firestop Engineering Judgement under Engineering Services and download an Engineering Judgment Request Form. Fill out the required fields. Accurate information helps expedite your request.

4. Fill up the customer, project information and application description. Attach drawings to be clearer about the requirements of the application. Click request service.

5. A Hilti firestop specialist will reach out to you through email for clarification and will provide you the Engineering Judgement with the firestop system solution.

Source: Engineering judgement guidelines from firestop.org