Category A And B Doors
Category b doors a fire door that requires the use of an edge seal to comply with positive pressure requirements.
Category a and b doors. Once tested the door and frame receive a label that describes the amount of time the component is expected to provide protection when exposed to fire. These doors are usually used for stairwell doors but are sometimes used at all the rated walls in a building. These door slabs systems may have been evaluated with an edge sealing system category g field applied to the labeled frame or door. For example for most applications the 2015 edition of the international building code ibc requires a two.
Smoke seal labels in addition to standard fire ratings a 3 hour b 90 or 60 minute c 45 minute and 20 minute some positive pressure doors may also be required to carry a smoke seal s label. Steel front doors are stronger and more energy efficient but are limited on design styles. 100 square inches of exposed glass is allowed. A fire door that requires the addition of and edge seal to comply with positive pressure requirements.
Class a 3 hour approved for doors in dividing fire walls with openings not exceeding 1 200 sq. Doors with a 60 minute rating are also classified as b label doors and are used in some interior exit stairway and ramp enclosures. Fiberglass options combine the versatile designs of wooden doors with the strength of steel. Woodharbor 20 minute fire rated doors fall into category b classification as shown above.
Rating of the fire door assembly is usually required to be 90 minutes aka b label. When combined all of the components of the door form an assembly that protects the opening. Category b doors a fire door slab that may have been evaluated with the addition of a category g edge sealing system between the door and frame. The andersen 2500 series self storing storm door is the andersen 2500 series self storing storm door is a heavy duty and seasonal ventilation storm door that offers a wide variety of features and options.
In some cases category g sealing systems might be required on the meeting stiles of pairs of category a doors. To achieve the supplemental s label a door must also pass for smoke and air infiltration. 1 1 2 hour rating for a 2 hour wall. Class c 0 75 hour approved for doors in corridor or room partition opening not exceeding 1 200 sq.
Doors are tested following standards including ul10b ul10c astm e2074 and nfpa 252. All intumescence and or gasketing is furnished by others. No glass is allowed in these doors. These doors are used for openings in walls separating buildings that are joined together.
Class b 1 5 hour approved for doors in vertical shall openings not exceeding 1 200 sq. The edge seals are typically added to the frame or field applied to the door i e.