Home Glossary of Terms Glossary of suspended timber floor terminology
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Terminology used to describe building components and construction might as well be a foreign language for those who are not familiar with it. Whilst it is appreciated that certain words have other meanings we have listed below an explanation of words often used when discussing the structure of a suspended timber floor. We hope that you find this useful.


Air Brick: A ventilation opening through a wall from a sub floor void to the outside. Sometimes called an air vent. (See sub floor ventilation)

Brick Pier(s): Vertical brick built column(s) sometimes used as an alternative to a sleeper wall to support a plate. (See Plate)


Boards: An abbreviation for floor boards.


DPC: An abbreviation for Damp Proof Course. Wall plates should be bedded on a damp proof material to protect them from moisture and possible decay.


Floor Brad: A type of nail once used to secure floor boards.


Joist: A bearing timber to which the floor boards are nailed. A ceiling may also be attached to the underside of a joist.


Joist hanger: A galvanised metal 'shoe' secured to masonry or timber to support the end of a joist. Often used to support joist ends thereby avoiding direct contact with masonry.


Lost head: A type of nail used to secure floor boards.


Nogging: Sometimes referred to as strutting. Inserted between large dimension joists to stiffen a floor and prevent joists twisting or tilting. Two types used; herring bone or solid.


Oversite: The ground that is beneath a ground floor level suspended timber floor. In Scotland it is called the Solum.


Plate: See Wall Plate.


Sleeper Wall: A wall within the sub floor void at ground floor level to provide intermediate support for the floor joists. Often a 'Wall Plate' is present on top of a sleeper wall.


Span: The distance between two points of support.


Strutting: Sometimes referred to as Nogging. Inserted between large dimension joists to stiffen a floor and prevent joists twisting or tilting. Two types used; herring bone or solid.


Sub Floor Ventilation: The movement of air beneath a ground floor suspended floor facilitated by air bricks at the appropriate level that penetrate  external walls.


Sub Floor Void: The space beneath a floor.


Suspended Floor: Consists of bearing timbers called joists covered by floor boards


T & G Boards: Softwood floor boards that have a protruding 'tongue' along one edge and a 'groove' along the other hence the term 'Tongue and Groove'.


Trimmer: A larger dimension joist that supports cut (trimmed) joists to create an opening in a floor e.g. for a stair case or fire place. A trimmer is supported by trimming joists which are also a larger dimension due to the increased weight they have to support.


Wall Plate: A wood member that provides a level bearing and fixing point for joists and distributes load from the joists to the wall or support below the plate.


Wrap: Term used to describe the wrapping of timber in a damp proof material to prevent direct contact with masonry that is damp or may become damp.
Contact Peter: Email - info@dampdecay.co.uk - Telephone: 015242 71794