Facia or Fascia - A flat board, band, or face, used sometimes by itself but usually in combination with moldings, often located at the outer face of the cornice.

Filler (wood) - A heavily pigmented preparation used for fining and leveling off the pores in open-pored woods.

Fire-Resistive - In the absence of a specific ruling by the authority having jurisdiction, applies to materials for construction not combustible in the temperatures of ordinary fires and that will withstand such fires without serious impairment of their usefulness for at least 1 hour.

Fire Retardant Chemical - A chemical or preparation of chemicals used to reduce flammability or to retard spread of flame.

Fire Stop - A solid, tight closure of a concealed space, placed to prevent the spread of fire and smoke through such a space. In a frame wall, this will usually consist of 2 by 4 cross blocking between studs.

Fishplate - A wood or plywood piece used to fasten the ends of two members together at a butt joint with nails or bolts. Sometimes used at the junction of opposite rafters near the ridge line.

Flagstone (flagging or flags) - Flat stones, from 1 to 4 inches thick, used for rustic walks, steps, floors, and the like.

Flashing - Sheet metal or other material used in roof and wall construction to protect a building from water.

Fly Rafters - End rafters of the gable overhang supported by roof sheathing and lookouts.

Footing - A masonry section, usually concrete, in a rectangular form wider than the bottom of the foundation wall or pier it supports.

Foundation - The supporting portion of a structure below the first floor construction, or below grade, including the footings.

Framing, balloon - A system of framing a building in which all vertical structural elements of the bearing walls and partitions consist of single pieces extending from the top of the foundation sin plate to the roof plate and to which all floor joists are fastened.

Framing, platform - A system of framing a building in which floor joists of each story rest on the top plates of the story below or on the foundation sill for the first story, and the bearing walls and partitions rest on the subfloor of each story.

Frieze - In house construction a horizontal member connecting the top of the siding with the soffit of the cornice.

Frostline - The depth of frost penetration in soil. This depth varies in different parts of the country. Footings should be placed below this depth to prevent movement.

Fungi, wood - Microscopic plants that live in damp wood and cause mold, stain, and decay.

Fungicide - A chemical that is poisonous to fungi.

Furring - Strips of wood or metal applied to a wall or other surface to even it and normally to serve as a fastening base for finish material.