Framing & Fireblocking in a Basement

Purpose

• The way that fireblocking is installed provides an indication of what the overall purpose of the material is used for. The primary purpose of fireblocking material is to prevent fire in concealed spaces, especially inside of the walls. Fireblocking is used in situation where the walls have drywall on only one side, such as in basement walls. Gaps between the framing and the concrete wall provide a perfect place for fires to creep in, once a fire is started.

Materials

• Fireblocking materials can consist of various types of fire-retardant insulation, but they usually consist of certain types of hardwoods used to create a barrier between an open space and the space in the home above it. Wood needs to be as thick as possible to hold off the effects of fire, but thinner nonwood materials can be used also. Some of these include gypsum board, glass fiber and cement fiber board.

Framing

• Framing the walls of a basement using fireblocking material is done in such a way that the fireblocking material is used to cut off or cover existing horizontal and vertical draft openings. The Prince William County Department of Developmental Services notes that the most critical area to use fireblocking material in is the space between the basement's concrete wall and the top plate of the studded exterior wall. Also critical is the area between the concrete wall and the sill plate.

Stairs

• Stairs are a critical part of the basement, and you should install fireblocking there, too. Install fireblocking on the underside of each stair to prevent fire from making its way above to the rest of the house via the underside of the stairs. Also fireblock the walls enclosing the underside of the stairway so that they prevent fire from making its way underneath in the first place.