IFC_5b.constructionjointspowerpoint_revised.ppt

Editor's Notes

• #1: The following presentation is designed to help you understand firestopping and how that relates to construction joints located within the building construction industry. Applications such as top-of-wall or head-of-wall joints, control joints, along with curtain wall or edge-of-slab joints will be discussed.
• #2: So why is there such a concern about fire-resistive construction joints? Because they move and present a weakness in fire containment if not properly firestopped! Not only is fire performance a key factor for these joints, but movement is equally taken into consideration. Before each of these applications are subjected to the fire test (UL 2079/ASTM E1966), these construction joints are cycled through the intended movement. As an example, if a 1 inch joint is going to be tested for 50% movement, the joint is extended to 1-1/2 inches, then compressed to 0.5 inches and returned to 1 inch. This process is repeated until 500 cycles are completed in most cases (See Slide 9 for more information). Movement of these construction joints can be caused by many factors including: Load – the placement or movement of machines, equipment, furniture, etc. within a facility for daily operation. This change in weight can cause a wall or floor joint assembly to expand or compress. Movement – natural events such as earthquakes, tornados and hurricanes can cause wall and floor assemblies to move in both horizontal and vertical directions. Differing assembly types – the use of gypsum, concrete, concrete over metal deck, masonry block, etc. can cause wall and floor assemblies to react differently to load, movement and thermal changes. This reaction can cause fire-rated joints to expand or contract. Thermal – Changes in temperature can have different reactions on floor and wall assemblies based upon construction type and actual temperature. These changes can cause expansion of contraction of a construction joint.
• #3: These fire-rated joint applications can be found in the following locations: Curtain Wall Gap (also known as edge-of-slab) – the gap located between the exterior wall or façade and the fire-rated floor assembly. These exterior walls are typically not fire-rated and may consist of brick, stone, concrete, glass or other materials specified by the building Architect Top-of-Wall (also known as Head-of-Wall) – the gap located between the top of a fire-rated wall assembly and the underside of the floor or roof assembly located above. Expansion Joints – May be horizontal or vertical joints located in both wall and floor assemblies. Designed to allow for movement within these fire-rated assemblies.
• #4: When working with firestop system and construction joints, it is important to understand all of the terminology: Overall depth of floor assembly – this is the dimension from the bottom of the flute (closest point to the wall assembly below) to the upper most part of the floor (in this case the top of the concrete poured floor) Flute depth – the height or the dimension of the flute from the bottom to the top Joint width – the dimension from the wall below to the lowest point of the floor assembly above (in this case the flute) Minimum concrete depth – the thinnest part of the floor assembly Valley – the lower part of the corrugated deck that is filled with concrete.
• #5: Additional construction joint terminology that is important to understand especially when utilizing laboratory test reports and listings include: Assembly rating – Measures both the fire and temperature ratings on the non-fireside of the test assembly (combination of F and T rating). This is measured in hours (i.e. 1, 2, 3 or 4) Movement – the distance of travel that a firestop joint system is tested to based upon system design / capabilities. Most firestop joint systems will specify movement of extension and compression. Construction joint systems with movement capabilities usually specify a nominal joint width and the movement (extension/compression) in either a numerical value or as a percent of the nominal joint width. Nominal joint width – the “normal or standard” design distance between each assembly (wall or floor) Extension – This movement is the distance from the nominal joint width to maximum width as designed and tested Compression - This movement is the distance from the nominal joint width to minimum width as designed and tested Percent (%) extension / compression – The calculation of the minimum and maximum joint width of a test joint system as determined from the nominal joint width. For example: a construction joint with a nominal width of 1” and 50% extension/compression will have compression movement down to ½” and extension up to 1-1/2” Mineral wool compression – Many tested systems specify that the backing material (in many cases mineral wool) must be compressed a specific percent (%) for proper installation and performance. For example: a construction joint with a nominal width of 3” and requiring 50% compression will require the installer to take mineral wool 6” wide and squeeze (compress) it down to fit into the 3” joint. Sealant depth – the minimum amount of firestop material that is required for proper installation according to the laboratory tested system. In order to achieve the desired rating of the firestop system – ALL components (minimum requirements) of the tested system must be achieved on the jobsite.
• #6: ASTM E 1966 and UL 2079 are the basic test standards used to evaluate fire test performance of construction joint firestop system. The types of joints that may be tested using these standards include: Floor to floor – where two rated floor assemblies meet (control joint) Floor to wall – where a rated floor assembly intersects with a rated wall assembly Head of wall (top of wall) – where a rated wall assembly meets the underside of a rated floor/ceiling assembly Wall to wall - where two rated wall assemblies meet (control joint) These firestop systems are tested in duration (time) equal to the ratings of the wall/floor assemblies. In the case where there are two different fire ratings, the system is tested to the minimum rated assembly. For example: an 1-hour rated gypsum wall intersecting a 2-hour concrete floor assembly. The system would be tested for 1-hour.
• #7: The ASTM E 1966 and UL 2079 test standards have specific criteria which must be measured in order for a firestop system to pass and become listed. These include: ASTM 1399 – For joint systems requiring movement, the firestop system will be cycled 500 times (for class I and II) through it intended range of movement before being exposed to fire. The joint is then extended to its maximum width and put to the fire test. ASTM 119 – The same time/temperature curve is used for construction joints as for through penetrations. The temperature at 10 minutes averages 1300 oF and accelerates nearing 2000 oF in 3-hours Assembly rating – Temperature of the non fire side is critical. Measurements are taken throughout the test measuring the temperature of the joint assembly. The way this is measured is dependent on the test standard chosen. If using the UL 2079 standard - if any of the thermocouples reach 325 oF plus the initial air temperature at the beginning of the test (i.e. 75 oF air temp + 325 = 400 oF), the test stops and the time is recorded and the system is given an assembly rating rounded down to the whole hour (i.e. 1, 2, 3 & 4-hr). There is an exception to this rule and that is where the joint width is greater than 6-inches – then an average of all the thermocouple readings are used and the temperature rise can be no more than 250 oF above the initial temperature. The ASTM E1966 test uses a similar format as the UL 2079 however their exception for joint width starts at 4-inches. At that point, average temperature rise of thermocouple readings on the face of the test specimen are used (250 oF above the initial temperature). Within 10 minutes after the end of the fire endurance test, the test specimen is subjected to hose stream test. This test is for head-of-wall and wall-to-wall joints only. The other joint tests do not require the hose stream test. The purpose of the hose stream test is to provide impact, erosion and cooling effects to the firestop system ensuring proper performance during a fire. The hose stream test is conducted in the following manner: Located the nozzle of the hose no further than 20 feet from the test specimen Direct the hose stream first at the bottom and then at all parts of the exposed surface, making changes in direction slowly while keeping the stream approximately 1 ft apart. Time and pressure for the hose stream are determined as follows: Fire Endurance (min.) Water Pressure at Base of Nozzle (psi) Duration of Application (sec/ft2) 240 < 480 45 3.0 120 < 240 30 1.5 90 < 120 30 0.9 < 90 30 0.6
• #8: This is a visual slide that demonstrates what Fire Tests are used for building construction materials. Floor and wall assemblies: Tested in accordance with ASTM E119, UL 263 and/or NFPA 251 Joint systems: Tested in accordance with ASTM E1966 / UL 2079 Through-penetration systems: Tested in accordance with ASTM E814 / UL 1479
• #9: Based upon the type of movement required/desired for the tested firestop joint system, the movement table is used. Both the number of movement cycles and the cycle rate are the two criteria that can be modified.
• #10: The cycling of a firestop joint is a critical part of the firestop design. The ability of the firestop sealant or spray to maintain the proper bond with the wall/floor assembly, compress or stretch with the movement and maintain the proper fire protection must be defined in order to achieve a testing certificate. The most difficult motion for the firestop joint system is when the joint and extended to its maximum. Here the firestop and backing material (mineral wool) is at its thinnest dimension. This is considered the “worst case scenario” and is why the joint is fire tested in this position.
• #11: When picking a firestop joint system, it is important to understand the nomenclature associated with the type of listed system chosen. For this example we use the Underwriters Laboratories Inc. (UL) nomenclature for Firestop Joint Systems. A typical UL Listing for a firestop joint system is listed as an alpha-numeric system (i.e. HWD-0000). Each of the letters and numbers have a meaning, which is important to understand. The letters represent the type of firestop joint system: FF – Floor to floor joint: System used when two fire-rated floor assemblies intersect FW - Floor to wall joint: System used when a fire-rated floor assembly intersects with a fire-rated wall assembly HW – Head of wall joint: System used when a fire-rated wall assembly intersects to the underside of a fire-rated floor assembly WW – Wall to wall joint: System used when two fire-rated wall assemblies intersect D – Dynamic: Indicates that the firestop joint system is designed and tested for movement capabilities S – Static: Indicates that the firestop joint system has NOT been designed or tested for movement The numbers represent the maximum size of the firestop joint system design: 0000 – 0999: a joint system that is designed for joints 2-inches wide or less 1000 – 1999: a joint system that is designed for joints greater than 2-inches wide up to 6-inches 2000 – 2999: a joint system that is designed for joints greater than 6-inches wide up to 12-inches 3000 – 3999: a joint system that is designed for joints greater than 12-inches wide up to 24-inches 4000 – 4999: a joint system that is designed for joints greater than 24-inches
• #12: To ensure proper fire protection of any firestop system, it is critical that the installer follows the recommended installation instructions from the manufacturer. Items such as application temperature, storage, safety precautions, etc. are important to understand and follow. In addition, to maintain the fire-rated as tested and listed – the installer should also have a drawing (cut sheet) of the listed system they are installing. By verifying all of the pertinent information of the installation – they will help ensure proper system performance if a fire were to occur.
• #13: The use of sprayed-on fireproofing can change the application of a top-of-wall joint assembly. In many cases the installation process is the same, however you must check with the firestop manufacturer and the test certifications to ensure the firestop system you have chosen includes the use of fireproofing.
• #15: There are other educational seminars available on the International Firestop Council’s website. Please take advantage of these at www.firestop.org