Search Legislation

The Gas Safety (Installation and Use) Regulations 1998

 Help about what version

What Version

 Help about opening options

Opening Options

More Resources


This is the original version (as it was originally made).


Safe use of pipes

18.—(1) No person shall install any installation pipework in any position in which it cannot be used with safety having regard to the position of other pipes, pipe supports, drains, sewers, cables, conduits and electrical apparatus and to any parts of the structure of any premises in which it is installed which might affect its safe use.

(2) Any person who connects any installation pipework to a primary meter shall, in any case where electrical equipotential bonding may be necessary, inform the responsible person that such bonding should be carried out by a competent person.

Enclosed pipes

19.—(1) No person shall install any part of any installation pipework in a wall or a floor or standing of solid construction unless it is so constructed and installed as to be protected against failure caused by the movement of the wall, the floor or the standing as the case may be.

(2) No person shall install any installation pipework so as to pass through a wall or a floor or standing of solid construction (whether or not it contains any cavity) from one side to the other unless—

(a)any part of the pipe within such wall, floor or standing as the case may be takes the shortest practicable route; and

(b)adequate means are provided to prevent, so far as is reasonably practicable, any escape of gas from the pipework passing through the wall, floor or standing from entering any cavity in the wall, floor or standing.

(3) No person shall, subject to paragraph (4), install any part of any installation pipework in the cavity of a cavity wall unless the pipe is to pass through the wall from one side to the other.

(4) Paragraph (3) shall not apply to the installation of installation pipework connected to a living flame effect gas fire provided that the pipework in the cavity is as short as is reasonably practicable, is enclosed in a gas tight sleeve and sealed at the joint at which the pipework enters the fire; and in this paragraph a “living flame effect gas fire” means a gas fire—

(a)designed to simulate the effect of a solid fuel fire;

(b)designed to operate with a fanned flue system; and

(c)installed within the inner leaf of a cavity wall.

(5) No person shall install any installation pipework or any service pipework under the foundations of a building or in the ground under the base of a wall or footings unless adequate steps are taken to prevent damage to the installation pipework or service pipework in the event of the movement of those structures or the ground.

(6) Where any installation pipework is not itself contained in a ventilated duct, no person shall install any installation pipework in any shaft, duct or void which is not adequately ventilated.

Protection of buildings

20.  No person shall install any installation pipework in a way which would impair the structure of a building or impair the fire resistance of any part of its structure.

Clogging precautions

21.  No person shall install any installation pipework in which deposition of liquid or solid matter is likely to occur unless a suitable vessel for the reception of any deposit which may form is fixed to the pipe in a conspicuous and readily accessible position and safe means are provided for the removal of the deposit.

Testing and purging of pipes

22.—(1) Where a person carries out work in relation to any installation pipework which might affect the gastightness of any part of it, he shall immediately thereafter ensure that—

(a)that part is adequately tested to verify that it is gastight and examined to verify that it has been installed in accordance with these Regulations; and

(b)after such testing and examination, any necessary protective coating is applied to the joints of that part.

(2) Where gas is being supplied to any premises in which any installation pipework is installed and a person carries out work in relation to the pipework, he shall also ensure that

(a)immediately after complying with the provisions of sub-paragraphs (a) and (b) of paragraph (1) above, purging is carried out throughout all installation pipework through which gas can then flow so as to remove safely all air and gas other than the gas to be supplied;

(b)immediately after such purging, if the pipework is not to be put into immediate use, it is sealed off at every outlet with the appropriate fitting;

(c)if such purging has been carried out through a loosened connection, the connection is retested for gastightness after it has been retightened; and

(d)every seal fitted after such purging is tested for gastightness.

(3) Where gas is not being supplied to any premises in which any installation pipework is installed—

(a)no person shall permit gas to pass into the installation pipework unless he has caused such purging, testing and other work as is specified in sub-paragraphs (a) to (d) of paragraph (2) above to be carried out;

(b)a person who provides a gas supply to those premises shall, unless he complies with sub-paragraph (a) above, ensure that the supply is sealed off with an appropriate fitting.

Marking of pipes

23.—(1) Any person installing, elsewhere than in any premises or part of premises used only as a dwelling or for living accommodation, a part of any installation pipework which is accessible to inspection shall permanently mark that part in such a manner that it is readily recognisable as part of a pipe for conveying gas.

(2) The responsible person for the premises in which any such part is situated shall ensure that the part continues to be so recognisable so long as it is used for conveying gas.

Large consumers

24.—(1) Where the service pipe to any building having two or more floors to which gas is supplied or (whether or not it has more than one floor) a floor having areas with a separate supply of gas has an internal diameter of 50 mm or more, no person shall install any incoming installation pipework supplying gas to any of those floors or areas, as the case may be, unless—

(a)a valve is installed in the pipe in a conspicuous and readily accessible position; and

(b)a line diagram in permanent form is attached to the building in a readily accessible position as near as practicable to—

(i)the primary meter or where there is no primary meter, the emergency control, or

(ii)the gas storage vessel,

indicating the position of all installation pipework of internal diameter of 25 mm or more, meters, emergency controls, valves and pressure test points of the gas supply systems in the building.

(2) Paragraph (1) above shall apply to service pipework as it applies to a service pipe except that reference therein to “50 mm or more” is to be reference to “30 mm or more”.

(3) In paragraph (1)(b) above “pressure test point” means a gas fitting to which a pressure gauge can be connected.

Back to top


Print Options


Legislation is available in different versions:

Latest Available (revised):The latest available updated version of the legislation incorporating changes made by subsequent legislation and applied by our editorial team. Changes we have not yet applied to the text, can be found in the ‘Changes to Legislation’ area.

Original (As Enacted or Made): The original version of the legislation as it stood when it was enacted or made. No changes have been applied to the text.


Opening Options

Different options to open legislation in order to view more content on screen at once


More Resources

Access essential accompanying documents and information for this legislation item from this tab. Dependent on the legislation item being viewed this may include:

  • the original print PDF of the as enacted version that was used for the print copy
  • lists of changes made by and/or affecting this legislation item
  • confers power and blanket amendment details
  • all formats of all associated documents
  • correction slips
  • links to related legislation and further information resources