A pattress or pattress box or fitting box (in the United States and Canada, electrical wall switch box, electrical wall outlet box, electrical ceiling box, switch box, outlet box, electrical box, etc.) is the container for the space behind electrical fittings such as power outlet sockets,

light switch In electrical wiring, a light switch is a switch most commonly used to operate electric lights, permanently connected equipment, or electrical outlets. Portable lamps such as table lamps may have a light switch mounted on the socket, base, or i ...

es, or fixed light fixtures. Pattresses may be designed for either surface mounting (with cabling running along the wall surface) or for embedding in the wall or

skirting board In architecture, a baseboard (also called skirting board, skirting, wainscoting, mopboard, trim, floor molding, or base molding) is usually wooden or vinyl board covering the lowest part of an interior wall. Its purpose is to cover the joint be ...

. Some

electrician An electrician is a tradesperson specializing in electrical wiring of buildings, transmission lines, stationary machines, and related equipment. Electricians may be employed in the installation of new electrical components or the maintenance ...

s use the term "pattress box" to describe a surface-mounted box, although simply the term "pattress" suffices. The term "flush box" is used for a mounting box that goes inside the wall, although some use the term "wall box". Boxes for installation within timber/plasterboard walls are usually called "cavity boxes" or "plasterboard boxes". A ceiling-mounted pattress (most often used for

light fixture A light fixture (US English), light fitting (UK English), or luminaire is an electrical device containing an electric lamp that provides illumination. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets for ...

s) is referred to as a "ceiling pattress" or "ceiling box".

British English British English (BrE, en-GB, or BE) is, according to Oxford Dictionaries, "English as used in Great Britain, as distinct from that used elsewhere". More narrowly, it can refer specifically to the English language in England, or, more broadl ...

speakers also tend to say "pattress box" instead of just "pattress". Pattress is alternatively spelt "patress" and Wiktionary lists both spellings. The word "pattress", despite being attested from the late 19th century, is still rarely found in dictionaries. It is etymologically derived from ''pateras'' (

Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

for bowls, saucers). Pattress page
– DIY''faq'' Wiki The term is not used by electricians in the United States.

Pattresses

Pattresses contain devices for input (switches) and output (sockets and fixtures), with transfer managed by

junction box An electrical junction box (also known as a "jbox") is an enclosure housing electrical connections. Junction boxes protect the electrical connections from the weather, as well as protecting people from accidental electric shocks. Construction ...

es. A pattress may be made of metal or plastic. In the United Kingdom, surface-mounted boxes in particular are often made from

urea-formaldehyde resin Urea-formaldehyde (UF), also known as urea-methanal, so named for its common synthesis pathway and overall structure, is a nontransparent thermosetting resin or polymer. It is produced from urea and formaldehyde. These resins are used in adhesive ...

or alternatively PVC and usually white. Wall boxes are commonly made of thin

galvanised Galvanization or galvanizing ( also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged ...

metal. A pattress box is made to standard dimensions and may contain embedded bushings (in standard positions) for the attachment of wiring devices (switches and sockets). Internal pattress boxes themselves do not include the corresponding faceplates, since the devices to be contained in the box specify the required faceplate. External pattress boxes may offer include corresponding faceplates, limiting the devices to be contained in the box. File:Sockets.jpg, External pattress boxes:
Power and Data Sockets Although cables may be joined inside pattress boxes, due simply to their presence at convenient points in the wiring, their main purpose is to accommodate switches and sockets. They allow switches and sockets to be recessed into the wall for a better appearance. Enclosures primarily for joining wires are called

es.

New work boxes

New work boxes are designed to be installed in a new installation. They are typically designed with nail or screw holes to attach directly to

wall stud A wall stud is a vertical repetitive framing member in a building's wall of smaller cross section than a post. It is a fundamental element in frame building. Etymology ''Stud'' is an ancient word related to similar words in Old English, Old No ...

s. File:New work box.jpg, New work pattress box.
Nails attach box to side of

stud Stud may refer to the following terms: Animals * Stud (animal), an animal retained for breeding ** Stud farm, a property where livestock are bred Arts and entertainment * Stud (band), a British progressive rock group * The Stud (bar), a gay ba ...

. Image:Opened light switch.JPG, New work pattress box.
Nails attach box to face of

via metal bracket.

Old work boxes

Old work boxes are designed to attach to already-installed wall material (usually drywall). The boxes will almost always have two or more ''parsellas'' (from Latin: "small wing ''or'' part). The parsellas flip out when the box screws are screwed, securing the box to the wall with the help of the four or more tabs on the front of the box. File:Hohlwanddose.jpg, German round old work pattress box File:Electrical box03.jpg, German round old work pattress box Image:Подрозетник C3M3.jpg, round old work pattress box

Alternative systems

In some countries, for instance in Germany, wall boxes for electrical fittings generally are not actual rectangular boxes at all but standard-sized round recessed containers. This has the advantage that the corresponding round holes can be simply drilled out with a

hole saw A hole saw (also styled holesaw), also known as a hole cutter, is a saw blade of annular (ring) shape, whose annular kerf creates a hole in the workpiece without having to cut up the core material. It is used in a drill. Hole saws typically ...

rather than needing the cutting-out of a rectangular cavity to accommodate the wall box. Even with those round-hole systems, the faceplates that cover them are mostly rectangular however.

Image gallery

Image:singsurf.jpg, UK-pattern single (1

gang A gang is a group or society of associates, friends or members of a family with a defined leadership and internal organization that identifies with or claims control over territory in a community and engages, either individually or collective ...

) white plastic surface pattress box Image:doubmetl.jpg, UK-pattern double (2 gang) metal wall box for sub-surface use Image:Pattress.jpg, US-style new work wall box with room for three light switches. To be nailed sideways to a wooden beam. Image:Opened light switch.JPG, US-style new work wall box (blue) behind two light switches. Not shown: the corresponding faceplate. File:VIKO light switch with fitting box.JPG, ψ-way light switch with fitting box File:TEM fitting boxes.JPG, TEM fitting boxes File:Preparing wires in junction box.JPG, round wall box File:Dual light switches with exposed wiring.jpg, Dual light switches in square wall box File:Three light switches with exposed wiring.jpg, Three light switches in square wall box

References

{{reflist

External links

DIY Wiki Pattress page
– more information on (British) pattresses and terminology Cables Electrical wiring