Through Penetration – UL Term for a hole made or left in a fire rated floor or Wall.

Annular Space – Is the gap between a penetrating item and the wall of the opening.

Point Contact – Where the penetrant has zero gap to a side of the opening. (Touching at one point).

Continuous Point Contact – Where the penetrant and the opening are the same size, so point contact is on all sides.

Authority Having Jurisdiction (AHJ) – This is code officials, fire marshals, inspectors that will be involved in approvals.

Engineering Judgment (E.J.) – Recommendation for a firestop solution in untested conditions. In conditions, where no tested system is available, the manufacture can write an engineering judgment based upon tested systems and their unpublished results to cover this specific condition. The AHJ may require that the contractor/manufacture submit and pay for an independent lab review of the engineering judgment.

FireSafing – Mineral Wool (or ceramic fiber material) is referred to as firesafing. Some AHJ's refer to firestopping as firesafing.

Intumescent – Product that expands (up to 30 times) when heated or burned. Helps to seal voids created by combustible materials or movement.

Membrane Penetration – In hollow construction, an opening made through one side (membrane) of the assembly.

Assembly Rating – The rating of the assembly (i.e. wall, floor, shaft, etc.) as specified by code. Typically it is tested by ASTM E-119.

Firestop Rating – The rating of the listed firestop being penetrated is specified by codes. Typically it is tested to ASTM E-814.

F-Rating – “Fire” Rating, the amount of time that the firestop system is rated for in regards to preventing fire from burning through. Recorded in hours or fractions.

T-Rating – “Temperature” Rating, The time it takes for the temperature on the non fire side to rise 325/deg. above ambient temperature. Recorded in hours or fractions.

L-Rating – “Air Leakage” Rating, the amount of air leakage through firestop systems at two temperatures, ambient and 400/deg. Recorded in CFM / sq ft of hole opening, with the lowest value < 1.

W-Rating – “Water Leakage” Rating, the amount of water leakage through firestop systems.

Head-of-Wall – The gap at the top of a rated wall to the deck above.

Curtain Wall Joint – A type of joint in multiple story construction with a non-load bearing exterior facade walls. It is the joint of the slab edge to the exterior façade wall.

Non-Combustible Penetrants – Pipes or other penetrants that do not burn or melt during fire exposure. Typically 1000 series (metal pipe).

Combustible Penetrants – Pipes, cables or other penetrants that burn or melt during fire exposure. Typically 2000 series (plastic and glass pipe), 3000 series (cables) and 5000 series (insulated pipe).