Designing Buildings - User contributions [en]

Pattress Plates

2025-12-22T16:27:35Z

PatrickBarry:

A pattress plate is a name for an anchor plate for a wall tie.

The term “pattress” is believed to derive from the French patrice or patresse, referring to a backing or support plate.

Structurally speaking, they are the method by which the very concentrated force in a tensioned wall tie is spread out onto a wide area of material to avoid local failures. The tie may pass through a building or structure and have an anchor on both ends, or may be driven and fixed into embedded material, to help tie back a retaining wall.

Sometimes, such as a railway viaduct that could not be excavated for installation, pattress plates may be present on both sides, but not actually connected. Their presence normally shows that a repair was carried out, but doesn't give much indication of the current condition of the structure. NDT (Non-Destructive Testing) measurement of the tie tension is difficult, and will need to consider seasonal temperature effects.

[[File:Marburg_-_Ritterstraße_02_ies.jpg|link=File:Marburg_-_Ritterstraße_02_ies.jpg]]

An example of a forged wrought iron pattress plate from Germany. S shapes are relatively common on agricultural buildings in the UK.

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[[File:Cast_iron_patress.jpg|link=File:Cast_iron_patress.jpg]]

An example of a cast iron pattress plate from Wells-next-the-sea, Norfolk. The lack of thread and nut on this end of the wall tie suggests that tightening was applied at the other end, or inside the building.

[[File:Pattress plate skew tie ductile iron.jpg]]

An example of a 1985 ductile steel patress plate. The off center bulge is to accomadate and spread forces from a wall tie that is an an angle to the wall. In this case, it is tying through a corner.

[[File:Pattress and ties through corner.jpg]]

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In historic building practice pattress plates were used to:

* Provide a solid fixing where masonry was weak, uneven or friable.
* Distribute point loads over a larger area.
* Create a true, flat plane for ironmongery or fittings.

They were commonly made from timber, slate or metal and were often built into the wall or floor during construction, rather than being surface mounted.

In classical and medieval masonry embedded timber pattresses were used to:

* Anchor iron straps, tie bars and railings.
* Receive door furniture and shutter hinges.
* Support grilles, hooks and wall-mounted fittings.

In these contexts, the pattress plate acted as a sacrificial or replaceable interface between hard masonry and metal fixings, reducing damage to the surrounding stone or brickwork.

When gas lighting, bell systems and early electrical fittings were introduced in the nineteenth century, builders adopted the pattress plate concept. A timber pattress was fixed or built into the wall, plaster was run up to it or over it and the fitting was screwed into the pattress rather than the masonry.

This is still visible in Victorian buildings where switches or bell pulls are mounted to flush timber pattress plates, sometimes hidden beneath decorative plates.

This idea has developed into the modern concept of the patress box, positioned behind power sockets, light switches and other electrical fittings, and containing wiring, switches and other circuitry. This may sometimes be secured to a timber or plywood pattress.

See Pattress for more information.

= Related articles on Designing Buildings =

* Aqueduct.
* Anchor beam
* Bolt.
* Bridge.
* Earth anchor
* Expansion anchor
* Fixing.
* Ground anchor
* Mechanical anchor
* Pattress.
* Percussion driven earth anchor
* Viaduct.
* Wall tie failure.
* Wall tie.

[[Category:DCN_Product_Knowledge]] [[Category:Products_/_components]] [[Category:Conservation]]

File:Pattress plate skew tie ductile iron.jpg

2025-12-22T16:26:10Z

PatrickBarry: An example of a more recent pattress plate, designed to spread forces from a steel tie that is acting at an angle to the wall.

An example of a more recent pattress plate, designed to spread forces from a steel tie that is acting at an angle to the wall.

File:Pattress and ties through corner.jpg

2025-12-22T16:23:20Z

PatrickBarry: Showing pattress plates and steel ties through the acute corner of a skew railway bridge.

Showing pattress plates and steel ties through the acute corner of a skew railway bridge.

Pattress Plates

2025-12-16T17:17:37Z

PatrickBarry:

A pattress plate is a name for an anchor plate for a wall tie. 
 
Structurally speaking, they are the method by which the very concentrated force in the tensioned wall tie is spread out onto a wide area of material to avoid local failures. The tie may pass through a building or structure and have an anchor on both ends, or may be driven and fixed into embedded material, to help tie back a retaining wall. 
 
Sometimes, such as a railway viaduct that could not be excavated for installation, patress plates may be present on both sides, but not actually connected. Their presence normally shows that a repair was carried out, but doesn't give mcuh indication to current condition of the structure. NDT measurement of the tie tension is difficult, and will need to consider seasonal tempreture effects. 
 
 
[[File:Marburg - Ritterstraße 02 ies.jpg]]

An example of a forged wrought iron pattress plate from Germany 
S shapes are relatively common on agricultural buildings in the UK. 
 
 
 
[[File:Cast iron patress.jpg]]

An example of a cast iron pattress plate from Wells-next-the-sea, Norfolk. The lack of thread and nut on this end of the wall tie suggests that tighening was applied at the other end, or inside the building.

[[Category:Articles_needing_more_work]] [[Category:Conservation]]

File:Cast iron patress.jpg

2025-12-16T17:15:17Z

PatrickBarry: A round cast iron pattress plate. Image provided to the creative commons by Leo Reynolds. from https://www.flickr.com/photos/lwr/474357637/

A round cast iron pattress plate. Image provided to the creative commons by Leo Reynolds. from [https://www.flickr.com/photos/lwr/474357637/ https://www.flickr.com/photos/lwr/474357637/]

File:Marburg - Ritterstraße 02 ies.jpg

2025-12-16T17:06:03Z

PatrickBarry:

Wrought iron pattress plate.

full size options and details at [https://commons.wikimedia.org/wiki/File:Marburg_-_Ritterstra%C3%9Fe_02_ies.jpg https://commons.wikimedia.org/wiki/File:Marburg_-_Ritterstra%C3%9Fe_02_ies.jpg]

File:Marburg - Ritterstraße 02 ies.jpg

2025-12-16T17:05:38Z

PatrickBarry: Wrought iron pattress plate

Wrought iron pattress plate

Pattress Plates

2025-12-16T17:04:09Z

PatrickBarry: Created page with "A pattress plate is a name for an anchor plate for a wall tie. Structurally speaking, they are the method by which the very concentrated force in the tensioned wall ..."

A pattress plate is a name for an anchor plate for a wall tie. 
 
Structurally speaking, they are the method by which the very concentrated force in the tensioned wall tie is spread out onto a wide area of material to avoid local failures. 
 
[[File:Marburg - Ritterstraße 02 ies.jpg|thumb|Marburg - Ritterstraße 02 ies]]

[[Category:Articles_needing_more_work]] [[Category:Conservation]]

Pattress

2025-12-16T16:44:18Z

PatrickBarry:

A pattress is a plywood or timber board fixed within in a partition to which equipment can be secured, such as ceiling roses, power outlets, basins, wall cabinets and so on. [[Pattress plates]] are the structural equivilent.

Confusingly, the term ‘pattress’ can also be used to refer to a container or box (correctly described as a pattress box) that is positioned behind power sockets, light switches and other electrical fittings, and contains wiring, switches and other circuitry. This may sometimes be secured to a timber or plywood pattress.

These boxes can also be referred to as a ‘wall box’ or 'installation box' or, when it is recessed into the wall, a ‘flush box’. If it is installed within timber or plasterboard walls, it can be referred to as a ‘cavity box’,‘plasterboard box’, or 'dry lining box'.

A pattress box can be designed to be either surface-mounted, or can be recessed into a wall or skirting board.

{|
| [[File:Surface_mounted_pattress.JPG|link=File:Surface_mounted_pattress.JPG]]
| [[File:Recessed_pattress.JPG|link=File:Recessed_pattress.JPG]]
|-
| Surface mounted pattress box
| Pattress box that will be recessed
|}

Pattress boxes are typically made from metal or plastic. PVC or urea-formaldehyde resin is often used for surface-mounted boxes, while thin galvanised metal is used for recessed boxes.

The generally have 'knockout' sections that can be removed as required to allow cables into the box.

= Related articles on Designing Buildings =

* Commercial lighting.
* Fused spur.
* General lighting v task lighting.
* Lamp.
* Light fitting.
* Lighting.
* Space classifications for lighting controls.
* The impact of lighting in retail design.

[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Product_Knowledge]] [[Category:Products_/_components]]