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{{Short description|Construction industry terms in the UK and Ireland}}
'''First fix and second fix''' are terms used in the UK and Irish [[construction|housebuilding]] and commercial building construction industry.

First fix comprises all the work needed to take a [[building]] from [[Foundation (architecture)|foundation]] to putting [[plaster]] on the internal [[wall]]s. This includes constructing walls, [[floor]]s and [[ceiling]]s, and inserting [[Electrical cable|cables]] for [[mains electricity|electrical supply]] and [[water pipe|pipes]] for [[water supply]].

Some argue that First Fix starts after the shell of the building is complete, and ends when the walls are plastered. Here is a list, in no particular order, of the elements of First Fix.
* Drain runs: must be downhill and straight
* Spare conduits: draw strings
* Soil pipes
* Copper pipes
* MVHR (mechanical [[heat recovery ventilation]] runs)
* Push-fit or other plastic piping
* Electrical back boxes
* Electricity cable runs
* Telephone, data and audiovisual cables
* Socket location
* Security
* Fire alarm
* Normal pipes
* Door bell
* Door frames
* Pocket doorframes
* Stair well: floating / cantilevered?
* Sound insulation
* Plasterboarding

The list is not exhaustive.

Second fix comprises all the work after the plastering of a finished house. Electrical fixtures are connected to the cables, [[sink]]s and [[bathtub|baths]] connected to the pipes, and [[door]]s fitted into doorframes. Second fix work requires a neater finish than first fix.

The division of work is a convenient description because [[electrician]]s, [[plumber]]s and [[carpenter]]s will probably have to make two separate visits to one property under construction, at separate times. [[Project manager]]s can report "first fix complete" or "second fix 50% done" and others can understand.

Some construction companies specialise in first fix work or second fix work, but most do both.

In North America, terms such as '''roughing in''' and '''finishing''' or '''rough-in''' and '''finish work''' are often heard, referring to similar concepts. Another related set of terms is '''outside work''' and '''inside work''' (the building is closed to the weather when the latter occurs). Carpenters speak of '''rough work''' and '''trim work''' (or framing versus trimming), and other fields have analogues, such as [[machining]] (roughing versus finishing cuts) and communications (rough [[draft document|draft]] versus revised draft).

== Electrical installations and "third fixes" ==

Electrical installations can be further divided into first, second and third fixes:<ref>Russell, Jack (2007). ''The Streetwise Subbie: How to Survive the Contracts Jungle''. 3rd ed. Oxford: Newnes. {{ISBN|978-0-7506-8061-5}}. App. 4</ref>

* First Fix:    Positioning and securing of accessory boxes
* Second Fix:   Preparation and positioning of cables
* Third Fix:    Termination of conductors to accessories and protective devices

As modern society's reliance on technology increases, the need to properly house sensitive electronic equipment becomes a greater concern.  The installation of this equipment takes place in the "third fix" segment of a construction project.  It is especially important that installation of sensitive electronic equipment be installed only when a construction site is dust-controlled and prepared for what would be considered "dust free" conditions.  For example, for the modern computer [[server room]], equipment would be installed only when dust and atmospheric conditions are minimized and controlled.  Similar to the atmospheric needs of medical and scientific research laboratories, the production of [[Discrete component|discrete]] [[semiconductor device]]s and [[integrated circuit]]s is undertaken in a [[cleanroom]] atmosphere where low levels of environmental pollutants such as particulates and airborne microbes are strictly minimised and most preferably eliminated.<ref>{{cite news |url= https://www.wired.com/gadgetlab/2010/10/inside-a-state-of-the-art-cleanroom/?pid=629&viewall=true |title= A Chip Is Born:Inside a State-of-the-Art Clean Room |publisher=[[Wired (magazine)|Wired]] |date=October 19, 2010 | first1=Dylan | last1=Tweney |first2=Jonathan | last2=Snyder }}</ref>

The UK national building specifications, British Standard 5295:1989, specifically addresses "clean room" environments serving electronics manufacturers, as well as the pharmaceutical industry (the Pharmaceutical Industry has, for some time, worked to the ISO standard 14644 which is subtly different).  Standard 5295:1989 specifically pertains to constructed interior spaces where higher than normal environmental standards must be maintained, in order to control particulate contamination, temperature and humidity.  It is only at the third fix stage, when building site conditions are rendered virtually ''dust free'', so as to minimise the introduction, generation and retention of particles which may contaminate equipment serving the electronics and pharmaceuticals manufacturing process, that the build-out of "clean room" spaces can commence.<ref>{{cite web |url=http://www.saa.gov.uk/resources/148164/clean_rooms_pn_no5.pdf |title= Industrial Committee Practice Note 5, Reevaluation 2005, Valuation of Subjects Containing Clean Rooms. |publisher= Scottish Assessors Association |date=2005 }}</ref>

==References==
{{Reflist|2}}

[[Category:Building engineering]]