BUILDING BYELAWS Made under Section 16 of the
Public Health Act 1936

THERMAL INSULATION AND FLUE PIPES

BUILDING BYELAWS

Made under Section 61 of the Public Health Act 1936, by the Mayor, Aldermen and Burgesses of the Borough of Shrewsbury acting by the Council for the Borough of Shrewsbury

1. After byelaw 53 of the series of building byelaws made by the Mayor, Aldermen and Burgesses of the Borough of Shrewsbury acting by the Council for the Borough of Shrewsbury on the 19th day of January 1954 and confirmed by the Minister of Housing and Local Government on the 8th day of March 1954 (and hereinafter called "the byelaws of 1954") there shall be inserted the following:-

Interpretation

 53A In this Part of these byelaws, unless the context otherwise requires, the following expressions have the meanings hereby assigned to them:-

  "appliance" means a heat producing appliance designed to burn solid or oil fuel, other than an appliance designed to burn oil fuel without being connected to a flue, and includes a cooker;
  "flue" means a passage for conveying the products of combustion from an appliance to the open air;
  "flue pipe" means a pipe containing a flue but does not include a pipe fitted as a liner in a chimney.

2. After byelaw 61 of the byelaws of 1854 there shall be inserted the following-

Openings in chimneys
 61A Subject to the provisions of byelaw 69, there shall be no opening into a flue in a chimney other than:-

(a) an opening made for the purpose of receiving the products of combustion from the appliance;
(b) an opening made for the purpose of inspection or cleaning and fitted with a non-combustible close fitting cover;
(c) an air inlet made in that part of the chimney which is in the room where the appliance to which it is connected is situated or which is in the open air;
(d) an opening fitted with a combined draught stabiliser and explosion door; or
(e) an opening made for the purpose of discharging the products of combustion into the open air.

3. To byelaw 64 of the byelaws of 1954 there shall be added the following
(3) In this byelaw references to a flue do not include a flue in a flue pipe.

4. For byelaw 85 of the byelaws of 1954 there shall be substituted the following:-

THERMAL INSULATION OF CERTAIN BUILDINGS
Thermal Insulation

85 - (1) This byelaw shall apply to any domestic building intended to be used wholly for human habitation and in the case of any domestic building intended to be partly so used to that part of the building which is intended to be so used.

 (2) The roof of every building or part of a building to which this byelaw applies shall, apart from any roof light or opening therein, be so constructed that, when the sum of the surface resistances of -
(a) the external surface of the roof, and
(b) the internal surface of the roof, or the lower surface of the ceiling of the storey immediately below the roof, is taken as 0.85, the thermal transmittance co-efficient of the roof, or of the roof in conjunction with any such ceiling, is not more than 0.25.

(3) For the purposes of this byelaw any floor which so projects or is otherwise so situated that its upper surface only is exposed to the outer air shall be deemed to be the roof of that part of the building beneath it.

(4) A roof, or a roof in conjunction with a ceiling, shall be deemed to have the resistance to the transmission of heat required by paragraph (2) of this byelaw if it is insulated in a manner provided in Table A of the fifth schedule.

(5) Every external wall of any building or part of a building to which this byelaw applies, including the internal surface finish thereof, shall, apart from any window or other opening therein, be so constructed that, when the sum of the surface resistances of the internal and external surfaces of the wall is taken as 1.00, the thermal transmittance co-efficient of the wall is not more than 0.30

(6) A wall shall be deemed to have the resistance to the transmission of heat required by the previous paragraph if it is insulated in a manner provided in Table B of the fifth schedule.
(7) The floor next to the ground of every building or part of a building to which this byelaw applies, or any floor thereof which projects or is otherwise so situated that its lower surface is exposed to the outer air, shall-
(a) be so constructed that, when the sum of the surface resistances of the upper and lower surfaces of the floor is taken as 1.00, the thermal transmittance co-efficient of the floor is not more than 0.25, or
(b) be constructed of suspended timber joists and tongued and grooved boarding not less than five-eights of an inch in thickness with or without the addition of any other material and having the space beneath the lowest timbers in the floor enclosed by walls on all sides apart from any necessary openings to afford ventilation, or
(c) be constructed of concrete laid upon the ground or upon hardcore filling.

(8) A floor shall be deemed to have the resistance to the transmission of heat required by sub-paragraph (a) of the previous paragraph if it is insulated in a manner provided in Table C of the fifth schedule.

(9) In this byelaw -
 "thermal transmittance co-efficient" means the number of British thermal units transmitted per hour through one square foot of the structure when there is a difference in temperature of one degree Fahrenheit between the air on the two sides of the structure;
 "surface resistance" means the reciprocal of the surface heat transfer co-efficient; and
 "surface heat transfer co-efficient2 means the amount of heat in British thermal units transferred per hour between each square foot of surface and the surrounding air when there is a difference in temperature of one degree Fahrenheit between the surface and the surrounding air.

(10) Nothing in this byelaw shall apply -
(a) to the roof, external wall or floor of any washhouse or watercloset not entered from within a building or part of a building to which the byelaw applies, or of a garage, boat-house, conservatory, shed or store attached to such a building or part of a building;
(b) to the external wall of any common stairway as defined in paragraph (3) of byelaw 46 (Fire resistance of floors, columns, beams and certain walls) of a building or part of a building to which this byelaw applies.

5. For byelaw 86 of the byelaws of 1954 there shall be substituted the following:- 
Interpretation

86 In this Part of the byelaws, unless the context otherwise requires-
"appliance", "flue" and "flue pipe" have the meanings assigned to them by byelaw 53A;
"domestic appliance" means an appliance with a rated output not exceeding 150,000 British thermal units per hour;
"slop sink" means a sink intended for receiving solid or liquid filth;
"soil pipe" means a soil pipe from a watercloset or a waste pipe from a slop sink or urinal; and
"waste stack" means a waste pipe which received the waste from two or more fittings such as baths, sinks (not being slop sinks), bidets or lavatory basins fixed in more than one storey of a building.

6. After byelaw 111 of the byelaws of 1954 there shall be inserted the following –
Flue pipes generally
 111A (1) A flue pipe, whether encased or not, shall not pass through-
(a) any floor;
(b) any roof space
(c) any ceiling other than a ceiling attached as a lining to the rafters or purlins of a pitched roof or to the joists of a flat roof; or
(d) any partition or wall other than an external wall of the building or, for the purpose of discharging into a flue in a chimney, a wall forming part of the chimney.

(2) Every flue pipe shall –
(a) be constructed of suitable non-combustible material of adequate thickness properly jointed and supported and shall be properly connected to the appliance and to any chimney into which it discharges;
(b) be so placed or shielded as to ensure that no part of the building can be ignited by heat from the pipe; and
(c) be so fitted as to discharge into a flue in a chimney complying with the requirements of Part III of these byelaws (or such of them as are relevant) or into the open air.
Materials for flue pipes for domestic appliances
 111B A flue pipe connected to a domestic appliance shall be deemed to satisfy the requirements with respect to materials of sub-paragraph (a) of paragraph (2) of the last preceding byelaw if –

(a) it is constructed of cast iron complying with British Standard 41 (Cast iron spigot and socket flue or smoke pipes) or of mild steel not less than three-sixteenths of an inch in thickness; or
(b) being a pipe other than a pipe connected with an open fire, so much of it as is within six feet of its junction with the appliance is constructed of materials satisfying paragraph (a) of this byelaw and the remainder is of asbestos cement complying with British Standard 835 (Asbestos cement flue pipes and fittings, heavy quality); or
(c) being a pipe not more than one foot six inches in length and connecting the outlet of a free-standing open fire to a chimney, it is made of sheet steel having a thickness of not less than No. 16 S.W.G. (standard wire gauge).

Placing and shielding of flue pipes for domestic appliances
 111C A flue pipe connected to a domestic appliance shall be deemed to satisfy the requirements of sub-paragraph (b) of paragraph (2) of byelaw 111A if -

 (1) where it passes through a roof, or, subject to the provisions of sub-paragraphs (c) and (d) of paragraph (1) of byelaw 111A, through a ceiling or wall, the flue pipe -
(a) is distant not less than three times its external diameter from any combustible material forming part of the roof, ceiling or wall; or
(b) (i) in relation to the roof or ceiling is separated from any combustible material forming part thereof by solid non-combustible material not less than nine inches thick;
(ii) in relation to the wall is separated from any combustible material forming part thereof by solid non-combustible material not less than nine inches thick if the combustible material is below or beside the pipe, or not less than twelve inches thick if the combustible material is above the pipe; or
  (c) is enclosed in a sleeve of metal or asbestos cement which-
(i) is carried through the roof, ceiling or wall to project for not less than six inches beyond any combustible material forming part of the roof, ceiling or wall;
(ii) has between it and the pipe a space of not less than one inch, properly packed with non-combustible insulating material; and
 (iii) where the roof, ceiling or wall is of hollow construction so that there is an air space between the outer surface of the sleeve and any combustible material in the roof, ceiling or wall, is so fitted that such material is distant not less than one inch from the outer surface of the sleeve and not less than one-and-a-half times the external diameter of the pipe from the outer surface of the pipe;
 (iv) where the roof, ceiling or wall is of solid construction, is so fitted that any combustible material forming part of the roof, ceiling or wall is distant not less than seven-and-one-half inches from the outer surface of the pipe and is separated from the outer surface of the sleeve by solid non-combustible material not less than four-and-one-half inches thick;

 (2) where it is adjacent to a wall or partition, the flue pipe is distant not less than three times the external diameter of the pipe from any combustible material forming part of the wall or partition, or if such material is protected by a shield of non-combustible material which-

(a) has an air space of not less than one-half of an inch between the shield and the combustible material or between the shield and nay non-combustible material which covers the combustible material; and
(b) is of such width and is fixed between the wall or partition and the pipe in such a position in relation to the pipe that it projects on either side of it for a distance of not less than one-and-a-half times the external diameter of the pipe,

the flue pipe is distant not less than one-and-a-half times the external diameter of the pipe from any such combustible material;

 (3) where it passes under any floor, roof or ceiling, the flue pipe is distant not less than four times the external diameter of the pipe from any combustible material forming part of the floor, roof or ceiling, or if such material is protected by a shield of non-combustible material which

(a) has an air space of not less than one-half of an inch between the shield and the combustible material or between the shield and any non-combustible material which covers the combustible material; and
(b) is of such width and is fixed between the floor, roof or ceiling and the pipe in such a position in relation to the pipe that it projects on either side of it for a distance of not less than two and a half times the external diameter of the pipe,

the flue pipe is distant not less than three times the external diameter of the pipe from any such combustible material;

 (4) where it discharges in a vertical direction into a flue in a chimney, the flue pipe is separated from any combustible material in the chimney by solid non-combustible material not less than nine inches thick all round the pipe;

 (5) where it discharges into the side of a flue in a chimney, the flue pipe is separated from any combustible material in the chimney by solid non-combustible material not less than nine inches thick if the combustible material is below or beside the pipe, or at least twelve inches thick if the combustible material is above the pipe.

Further provisions as to flue pipes generally
 111D A flue pipe which discharges into the open air -
(a) if it passes through a roof, shall comply with the requirements as respects chimneys of byelaw 67;
(b) in any other case, shall be carried up to a height of not less than three feet above-
(i) the level of the eaves; or
(ii) the top of any dormer window or other opening in the roof (being a window or opening which is within a distance of seven feet six inches, measured horizontally, from the flue pipe)
whichever is the higher.

Openings in flue pipes
 111DE There shall be no opening in a flue pipe other than -
(a) an opening made for the purpose of receiving the products of combustion from an appliance;
(b) an opening made for the purpose of inspection or cle4aning and fitted with a non-combustible close fitting cover;
(c) an air inlet;
(d) an opening fitted with a combined draught stabiliser and explosion door, or
(e) an opening made for the purpose of discharging the products of combustion into a flue in a chimney or into the open air.

7. After the fourth schedule to the byelaws of 1954 there shall be inserted the following:-

FIFTH SCHEDULE