Gable – The upper triangular-shaped portion of the end wall of a building.

Gable End – The entire end wall of a house having a gable roof.

Gable Roof – Defined under “Roof Types”.

Galvanized Iron – Sheet iron that has been dipped in molten zing to protect it against rust, used for roofing, flashing and damp-proof courses.

Gambrel Roof – Defined under “Roof Types”.

Gauge – A standard for measuring e.g. diameter of nails or wire and thickness of metal sheets etc.

Girder – A larger or principal beam used to support concentrated loads at isolated points along its length.

Girths – A band let into, or blocking fitted between structural members to keep them in proper alignment.

Glass Wool Insulation – An insulating material composed of glass fibers that are formed into lightweight blankets of uniform thickness. Also known as fiberglass insulation.

Glaze – To put panes of glass in a sash, frame or prepared opening. Transparent liquid applied to tiles before being fired in order to produce a glossy surface.

Glazed Door – A door fitted with glass panels.

Glazier’s Points – Small triangular pieces of tin or zing inserted into the rabbet or wood sash to help in holding the glass.

Glazier’s Putty – A mixture of whiting and linseed oil, sometimes including white lead, forming a plastic substance for fixing panes of glass into frame after installation of Glazier’s Points.

Glazing Bead – A moulding or stop around the inside of a frame to hold the glass in place.

Grade (Lumber) – To separate lumber into different established classifications depending upon its suitability for different uses. A classification of lumber. 

Grade – The surface slope. The level of the ground surface around the foundation wall. To modify the ground surface by cut and fill.

Grade Line – A pre-determined line indicating the purposed elevation of the ground around a building.

Gradient – A slope.   

Grain – A term used with reference to the arrangement or direction of wood fibers (spiral grain, cross grain, etc.) and to the relative width of the growth rings. (Coarse grain, fine grain, etc.)

Gravity Warm Air Heating – Defined under “Heating”.

Green Lumber – Unseasoned lumber; lumber in that free water still remains within the cells; lumber that has a moisture content above the fiber-saturation point (approximately 25 to 30%).

Grounds – Strips of wood or metal that are attached to walls before plastering along the floor line and around windows, doors and other openings as a plaster stop and thickness guide.

Ground floor – The floor of a building closet to finish grade.

Ground Water – Free subsurface water, the top of that is the water table.

Grout – A thin mixture of cement mortar and additional water.

Gusset – A wood or metal plate attached to one or both sides of a joint to increase its holding power.

Gutter – An eave trough used to convey rainwater from the roof to the downspout.

Gypsum Board – Wallboard made of gypsum plaster, with a covering of paper.