Glossary Letter J

J Channel

Metal edging used on drywall to give the edge a better finished appearance when a wall is not "wrapped" Generally, basement stairway walls have drywall only on the stair side. J Channel is used on the vertical edge of the last drywall sheet

Jack post

A type of structural support made of metal, which can be raised or lowered through a series of pins and a screw to meet the height required. Basically used as a replacement for an old supporting member in a building. See Monopost.

Jack rafter

A rafter that spans the distance from the wall plate to a hip, or from a valley to a ridge.

Jamb

The side and head lining of a doorway, window, or other opening. Includes studs as well as the frame and trim.

Joint

The location between the touching surfaces of two members or components joined and held together by nails, glue, cement, mortar, or other means.

Joint cement or Joint compound

A powder that is usually mixed with water and used for joint treatment in gypsum-wallboard finish. Often called "spackle" or drywall mud.

Joint tenancy

A form of ownership in which the tenants own a property equally. If one dies, the other automatically inherits the entire property.

Joint trench

When the electric company and telephone company dig one trench and "drop" both of their service lines in.

Joist

Wooden 2 X 8's, 10's, or 12's that run parallel to one another and support a floor or ceiling, and supported in turn by larger beams, girders, or bearing walls.

Joist hanger

A metal "U" shaped item used to support the end of a floor joist and attached with hardened nails to another bearing joist or beam.

Jumpers

Water pipe installed in a water meter pit (before the water meter is installed), or electric wire that is installed in the electric house panel meter socket before the meter is installed. This is sometimes illegal.