Historic Resources Committee

Hello all: I'm researching the modern applications of pressed-metal "tin" ceilings in existing (and new) buildings and I am interested in any information on code and fire-separation spec's along the following lines:

*What is the commonly accepted fire separation rating of a historic pressed metal ceiling (applied to wood furring over three-coat plaster)? One hour? If poor or no plaster -- 1/2 hour?

*Is it correct that removing a metal ceiling, then installing 5/8" Type X gypsum board as a subsurface, then re-installing the metal ceiling would improve the fire separation rating? If so, then to what rating or with what time gain?

*What about adding non-combustible insulation (two to three times the thickness of a typical wall stud) to the floor cavity? Would this achieve a 30-45 minute gain in fire separation?

NFPA does not seem to address this in their Historic Building guidelines. Any leads on or experience in dealing with this issues is much appreciated! Thanks -- Gordon (301-933-1071)

Gordon H. Bock (AIA#30205161)

National Archives Associates

P.O. Box 668

Kensington, MD 20895

Hello all: I'm researching the modern applications of pressed-metal "tin" ceilings in existing (and new) buildings and I am interested in any information on code and fire-separation spec's along the following lines:

*What is the commonly accepted fire separation rating of a historic pressed metal ceiling (applied to wood furring over three-coat plaster)? One hour? If poor or no plaster -- 1/2 hour?

*Is it correct that removing a metal ceiling, then installing 5/8" Type X gypsum board as a subsurface, then re-installing the metal ceiling would improve the fire separation rating? If so, then to what rating or with what time gain?

*What about adding non-combustible insulation (two to three times the thickness of a typical wall stud) to the floor cavity? Would this achieve a 30-45 minute gain in fire separation?

NFPA does not seem to address this in their Historic Building guidelines. Any leads on or experience in dealing with this issues is much appreciated! Thanks -- Gordon (301-933-1071)

Gordon H. Bock (AIA#30205161)

National Archives Associates

P.O. Box 668

Kensington, MD 20895

Hello all: I'm researching the modern applications of pressed-metal "tin" ceilings in existing (and new) buildings and I am interested in any information on code and fire-separation spec's along the following lines:

*What is the commonly accepted fire separation rating of a historic pressed metal ceiling (applied to wood furring over three-coat plaster)? One hour? If poor or no plaster -- 1/2 hour?

*Is it correct that removing a metal ceiling, then installing 5/8" Type X gypsum board as a subsurface, then re-installing the metal ceiling would improve the fire separation rating? If so, then to what rating or with what time gain?

*What about adding non-combustible insulation (two to three times the thickness of a typical wall stud) to the floor cavity? Would this achieve a 30-45 minute gain in fire separation?

NFPA does not seem to address this in their Historic Building guidelines. Any leads on or experience in dealing with this issues is much appreciated! Thanks -- Gordon (301-933-1071)

Gordon H. Bock (AIA#30205161)

National Archives Associates

P.O. Box 668

Kensington, MD 20895

Hello all: I'm researching the modern applications of pressed-metal "tin" ceilings in existing (and new) buildings and I am interested in any information on code and fire-separation spec's along the following lines:

*What is the commonly accepted fire separation rating of a historic pressed metal ceiling (applied to wood furring over three-coat plaster)? One hour? If poor or no plaster -- 1/2 hour?

*Is it correct that removing a metal ceiling, then installing 5/8" Type X gypsum board as a subsurface, then re-installing the metal ceiling would improve the fire separation rating? If so, then to what rating or with what time gain?

*What about adding non-combustible insulation (two to three times the thickness of a typical wall stud) to the floor cavity? Would this achieve a 30-45 minute gain in fire separation?

NFPA does not seem to address this in their Historic Building guidelines. Any leads on or experience in dealing with this issues is much appreciated! Thanks -- Gordon (301-933-1071)

Gordon H. Bock (AIA#30205161)

National Archives Associates

P.O. Box 668

Kensington, MD 20895

Hello all: I'm researching the modern applications of pressed-metal "tin" ceilings in existing (and new) buildings and I am interested in any information on code and fire-separation spec's along the following lines:

*What is the commonly accepted fire separation rating of a historic pressed metal ceiling (applied to wood furring over three-coat plaster)? One hour? If poor or no plaster -- 1/2 hour?

*Is it correct that removing a metal ceiling, then installing 5/8" Type X gypsum board as a subsurface, then re-installing the metal ceiling would improve the fire separation rating? If so, then to what rating or with what time gain?

*What about adding non-combustible insulation (two to three times the thickness of a typical wall stud) to the floor cavity? Would this achieve a 30-45 minute gain in fire separation?

NFPA does not seem to address this in their Historic Building guidelines. Any leads on or experience in dealing with this issues is much appreciated! Thanks -- Gordon (301-933-1071)

Gordon H. Bock (AIA#30205161)

National Archives Associates

P.O. Box 668

Kensington, MD 20895

Hello all: I'm researching the modern applications of pressed-metal "tin" ceilings in existing (and new) buildings and I am interested in any information on code and fire-separation spec's along the following lines:

*What is the commonly accepted fire separation rating of a historic pressed metal ceiling (applied to wood furring over three-coat plaster)? One hour? If poor or no plaster -- 1/2 hour?

*Is it correct that removing a metal ceiling, then installing 5/8" Type X gypsum board as a subsurface, then re-installing the metal ceiling would improve the fire separation rating? If so, then to what rating or with what time gain?

*What about adding non-combustible insulation (two to three times the thickness of a typical wall stud) to the floor cavity? Would this achieve a 30-45 minute gain in fire separation?

NFPA does not seem to address this in their Historic Building guidelines. Any leads on or experience in dealing with this issues is much appreciated! Thanks -- Gordon (301-933-1071)

Gordon H. Bock (AIA#30205161)

National Archives Associates

P.O. Box 668

Kensington, MD 20895

Hello all: I'm researching the modern applications of pressed-metal "tin" ceilings in existing (and new) buildings and I am interested in any information on code and fire-separation spec's along the following lines:

*What is the commonly accepted fire separation rating of a historic pressed metal ceiling (applied to wood furring over three-coat plaster)? One hour? If poor or no plaster -- 1/2 hour?

*Is it correct that removing a metal ceiling, then installing 5/8" Type X gypsum board as a subsurface, then re-installing the metal ceiling would improve the fire separation rating? If so, then to what rating or with what time gain?

*What about adding non-combustible insulation (two to three times the thickness of a typical wall stud) to the floor cavity? Would this achieve a 30-45 minute gain in fire separation?

NFPA does not seem to address this in their Historic Building guidelines. Any leads on or experience in dealing with this issues is much appreciated! Thanks -- Gordon (301-933-1071)

Gordon H. Bock (AIA#30205161)

National Archives Associates

P.O. Box 668

Kensington, MD 20895