Patent ID: 7275352

Claim:
A fire retardant panel door, comprising: a) a panel door having at least one door panel and stiles and rails; b) said door panel including an interior composite section formed by a first plurality of layers of intumescent materials and a first plurality of layers of fire resistant materials disposed between and laminated to a first pair of outer coverings to form a composite laminated door panel; c) each of said stiles including a first core formed of an incombustible material and a second plurality of layers of intumescent materials and a second outer covering to form a composite laminated stile; d) each of said rails including a second core formed of an incombustible material and a third plurality of layers of intumescent materials and a third outer covering to form a composite laminated rail; e) said first, second, and third plurality of layers of intumescent materials being activated to expand upon exposure to heat and/or fire to prevent the heat and/or fire from passing through said at least one door panel, said stiles and said rails of said panel door during a fire for at least 90 minutes; and f) said at least one door panel being connected to said panel door by joints; and said joints having a fourth plurality of layers each comprising intumescent and fire resistant materials, wherein said fourth plurality of layers of intumescent and fire resistant materials in said joints being activated to expand upon exposure to heat and/or fire to seal said joints in order to prevent the heat and/or fire from passing through said panel door during a fire for at least 90 minutes.