Fire and Smoke Intumescent Seals

Intumescent seals are a practical, well-established method of achieving fire resistance in designated fire doors. Heat from a fire causes the intumescent material to foam and swell, thus filling the gap between the door and frame and preventing the flow of hot gases and smoke. However, not all such seals are equal, and as concern over litigation grows, the thoughtful specifier must examine all the options to ensure that the seal chosen for each project really is the most appropriate. As the recognised leader in intumescent seal technology, Sealmaster offers products of proven performance and demonstrable cost-effectiveness, which can be specified with absolute confidence.

Sealmaster manufactures intumescent fire and smoke seals which are compatible with all types of fire-resisting door assemblies. Although the principal seals are intended for 30 or 60 minute rated doors, their design and performance characteristics indicate far longer endurance potential.

Sealmaster intumescent fire and smoke seals comply with all relevant British Standards and conform to the requirements of the Building Regulations.

The heat-treated aluminium holder is attractice in appearance, easy to install, and retains the intumescent material securely and correctly positioned in the rebate but without weakening either the frame or door, Robust and durable in use, it offers excellent vandal and damage-resistance, plus good heat conductivity to assist early intumescence.

Sealmaster's specially-formulated intumescent material is based on mono-ammonium phosphate, and is compounded to resist degredation by moisture or carbon dioxide. When triggered by heat it produces a low-pressure, high volume foam. A high-pressure exfoliated graphite foam is combined with Sealmaster's traditional material to produce the unique sealmaster Ultima seal, giving the benefits of high expansion with high pressure to restrict leaf movement in a fire.

The flexible and easy-to-replace flame-retarding elastomeric blade seal acts as a draught seal in normal use and prevents the passage of hot or cold smoke, noxious gases and flames during a fire, thereby keeping escape routes open.

Although the intumescent material remains hard under normal conditions, it intumesces rapidly at approximately 140^oC, and achieves a 40-fold expansion ratio. All seals contain sufficient intumescent material to ensure that the designed integrity ratings of both 30 and 60 minutes are achieved with comfortable margins.