Monthly Archives: June 2011

Requirements for Firestopping

firestoppingCODE REQUIREMENTS

Requirements for firestopping in building codes date to before the development of the International Building Code (IBC), which most states and local authorities follow today.

Although the IBC has gone through significant changes since its advent and not all types of construction require firestopping or fire-rated assemblies, one item that has stayed constant is that firestopping is required if a fire resistance-rated assembly is penetrated. IBC Chapter 7, “Fire and Smoke Protection Features,” outlines the requirements for fire resistance-rated assemblies and passive fire protection including firestopping for the various construction types. The sections in Chapter 7 provide detailed information on the minimum requirements for fire and smoke protection. (It is important to note that the IBC varies in content and requirements from version to version. The International Code Council, which develops the IBC, currently maintains a code-development cycle of three years. Because of the gap between code development and jurisdictional code adoption, the requirements will vary from state to state. Although the 2009 IBC is now available, some states are still using the 2003 or 2006 versions.)

The 2009 International Building Code provides requirements for firestopping in Sections 713 and 714, but in previous versions firestopping was located in Sections 712 and 713. The protection of penetrations of horizontal assemblies and fire resistance-rated wall assemblies is described in Section 713. Section 714 governs joints installed in or between fire resistance-rated assemblies and requires an approved fire resistance-rated system to be installed. The code requirements for firestop and smoke stop installations provide protection of the structure, and they also help maintain a minimum degree of protection for occupants who live or work in a structure and for fire safety personnel who must enter the building if a fire occurs.

Penetrations

A closer look at IBC (2009) Section 713 shows exactly what is required for protection when fire-resistant assemblies are penetrated. Section 713.3.1.2 states that through penetrations shall be installed and protected with an approved firestop system tested to ASTM E814 or UL 1479. The section also states that the fire-resistance rating of the firestop system (F rating) must be at least equal to the fire-resistance rating of the assembly penetrated. In Section 713.4.1.1.2, the code goes further to state that through penetrations of fire resistance-rated floors must have F and T ratings of at least one hour, but not less than the fire resistance rating of the floor penetrated. The code contains an exception for the T rating if the penetrating item is concealed in a wall cavity. However, when selecting systems for floor penetrations, it is necessary to find an approved firestop system that satisfies the F rating as well as the T rating when both are required.

Smoke Barriers

Section 710 in the 2009 IBC explains the protection requirements for smoke barriers in construction. It seems simple enough that a smoke barrier just needs to stop smoke, correct? Unfortunately, life is never that simple and neither is the building code. Smoke barriers are required to restrict the movement of smoke by definition, but when you look more closely you will see that Section 710.3 requires smoke barriers to also maintain a one-hour fire-resistance rating. Thus, if the smoke barrier assemblies must have a minimum one hour fire-resistance rating and must stop the movement of smoke, then what are the requirements for penetrations? All penetrations through smoke barrier assemblies must comply with Section 713, which, as mentioned, governs all firestopping for penetrations in the IBC. All penetrations in smoke barriers must be firestopped, but they also must stop smoke, which means that they need to have an L rating. Section 713.5 states that penetrations of smoke barriers must be tested to UL 1479 air-leakage testing and maintain an L rating of no more than 5 cubic feet per minute per square foot or 50 cubic feet per minute per any 100 square feet.

Understanding the specific requirements for construction that are prescribed in the building code is an elemental part of the construction process. Codes dictating passive fire protection ensure a minimum standard for passive life safety and property protection. The building codes are effective only when properly followed and enforced. No one wishes to be trapped in a burning building that was not firestopped to code. Maintaining minimum safety standards is what the building codes do for all of us.

Insert from “Stop Fire in its Tracks” by Riley Archer

 

Why use Air Admittance Valves (AAV)?

Air Admittance ValvesVent stacks that protrude out of a roof are used to protect the water that is inside the ‘P’ trap in a DWV system. It allows air into the system to balance the pressure inside the system and prevents the water in a ‘P’ trap from being siphoned off. The ‘P’ trap in all drains is used to prevent sewer gasses from backing up into an occupied space and causing obnoxious and unhealthy fumes. This is a simple and reliable method that has been used for many years and up until now was the only method available. Air Admittance Valves (AAV’s) are now a viable alternative. AAV’s are a pressure-activated, one-way mechanical vent. AAV’s allow air into a DWV system just like a vent stack to protect the ‘P’ trap and do not allow air to escape out.  When water flows into the drain system, the valve opens to allow air into the system. Once the pressure in the system is equalized, the valve closes thus allowing water to remain in the ‘P’ trap and prevent sewer gasses from escaping into the occupied space. Otherwise the AAV remains closed preventing the escape of sewer gas through the vent. AAV’s allow for easier installation, more design flexibility and uses less piping material than traditional vented systems. They eliminate the use of unsightly air vent stacks through the roof and lessen the risk of roof leaks. AAV’s are code approved and are an excellent alternative to vent stacks especially during remodeling and in new construction.

 

Conserving Water

Conserving WaterConservation is major concern with most municipalities today. In 1990, 30 US states reported water-stress conditions, in 2000 40 states, in 2009 45 states. 75% of water used indoors is in the bathroom and 25% of this is for the toilet. The average toilet uses 4 gallons per flush. By using water-saving devices you can reduce your water use by 35%. This means an average household which uses 130,000 gallons per year could save 4400 gallons of water per year or daily the average is 350 gallons and you could save 125 gallons of water per day just by retrofitting a toilet to use less water.

Saving water can be achieved with an insignificant investment. It can help your community and provide you benefits of saving money on your water bill.

There are a few ways to retrofit a toilet. The most common approach is a displacement device. The devices are placed inside the tank to take up room and the tank will not fill up with as much water each time you flush. Some devices used are bricks, or plastic bottles. This can reduce the water used by a toilet by 4 gallons a day but this is a short term solution. Bricks can deteriorate and cause damage to the other mechanisms and water bottles need to be weighted down so they will not float.

Another device is a displacement dam; the plastic dams are wedged into the tank on both sides decreasing the amount of water in the tank. This saves about 6 gallons of water per day. They are less likely to move around than the bricks or bottles, but they also deteriorate over time and affect the flush performance which can lead to double flushing.

The best solution is an early-close toilet flapper. An early-close toilet flapper shuts off the water flow to the bowl before the toilet tank is empty. The flapper is adjustable to find the ideal level that saves water and still cleans the toilet avoiding double flushing. The toilet flapper closes after a certain amount of water leaves the tank. This helps gravity drain the tank more quickly. This type of device can save up to 50% of present water consumption.

Why Clean Air Conditioner coils?

Summer is here and the temperatures are soaring. A properly functioning air conditioning unit is vital in order to survive the heat, especially in the South. Electric bills are also topping the charts. When was the last time you had your air conditioning coils cleaned? Dirt and debris collects on the surface of the coils restricting air flow and reducing the efficiency of the a/c unit. Cleaning the coils can improve the efficiency of the cooling system and reduce unnecessary wear on the compressor. An annual cleaning is recommended. The reason dirt collects on the surface is because the fan on the outside condensing unit pulls air through the fins on the coil along with dirt and debris which collects over time and restricts airflow. This also happens on the inside unit where the evaporator coil is located. Dirty coils cause equipment to run longer resulting in more wear and tear on the compressor. It uses more energy resulting in larger electric bills. The solution is to clean the coils on your air conditioning unit. The least labor intense way to do this is to use a good coil cleaner. Coil cleaners come in a range of choices, these are acid or alkaline used for cleaning condensing coils and an evaporator coil cleaner used for cleaning evaporator coils. An alkaline cleaner is most effective on greasy oily coils and acid is used to clean other organic matter.  Read all cautions, directions and warnings before beginning and follow all safety instructions printed on the label. Wear the recommended safety equipment. The use of coil cleaners is best left up to the professional contractor who has the proper equipment and experience in cleaning coils. Once the coils have been properly cleaned, don’t forget to change the air filters as well. This will assure that your unit will operate efficiently with minimum air flow restrictions. You are now ready for the summer heat.