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CERAMIC FLUE LINERS INSTALLATION GUIDELINES

Liners are installed with the male spigot pointing downwards. Schiedel Rapid HT Cement should be applied to the inside of the female socket and any excess projecting into the flue should be wiped off as installation progresses.

BUILDING REGULATIONS

The construction and application of chimneys and flues is covered by Building Regulations in conjunction with the relevant European Standards. Whilst these differ in emphasis, they all mandate the safe application of the chimney no matter where and how used. These Regulations and Standards dictate the minimum criteria which it is necessary to apply if the chimney or flue is to function safely and correctly.

Building control approval is necessary for building new chimneys and in some cases for relining old chimneys particularly if some alteration or change of the heating appliance occurs. The appropriate Regulations and Standards are listed below.

England & Wales:
Building Regulations Approved Document J

Scotland:
Building Regulations Technical Standards

Northern Ireland:
Building Regulations Technical Booklet L

Republic of Ireland:
Building Regulations Technical Guidance Document J

FLUE SIZING

It is important to match the internal diameter of the flue with the outlet on the appliance. It should never be less than the outlet diameter of the appliance. The appliance manufacturer’s chimney sizing recommendations should always be followed.

For open fires with a standard fire opening up to 500mm wide by 550mm high the minimum required flue diameter is 200mm round. For larger open fires, such as inglenooks, dog grate installations or special appliances and stoves designed to operate with a fire opening greater than 500mm x 550mm, the flue size should be at least 15% of the free unobstructed area of the fire opening (including sides if open). Many Decorative Fuel Effect gas fires (DFE’s) that imitate a coal or log burning open fire require the same chimney arrangement as for solid fuel open fires and must be installed in accordance with respective local building regulations

OPEN FIRE OPTION

Construction begins by providing a suitable foundation and constructional hearth in accordance with local Building Regulations and site requirements.

Form the fire opening onto the constructional hearth. 100mm of brick or blockwork must be built around the sides and back of the firechest to comply with Building Regulations.Apply Schiedel Rapid HT Cement onto a suitably formed fire gather.

Position the flue liner onto the prefabricated gather, female rebate facing upwards. Arrows on each flue liner indicate the directional flow of flue gases. Continue to apply Schiedel Rapid HT Cement to each flue liner, cleaning any access material from the joints.

RECESSED STOVE OPTION

A suitable cast-in-situ concrete slab lintel must be provided above the fireplace recess. Alternatively you could use suitable pre stressed lintels, for this method a support plate is required under the support block. It is recommended to have a minimum of 600mm length of flue pipe before connecting to the chimney.
 
The support block is bedded onto the slab lintel using weak mix mortar. A stainless steel adaptor or a section of Prima Smooth connecting flue pipe is used to connect from the support block to the stove flue pipe. This adaptor is pushed up onto the support block spigot (fibre rope should be used to create a seal).

FREE STANDING STOVE OPTION

A soot door must be provided below the flue pipe entry to allow for inspection and removal of soot and debris. A suitable wall sleeve is to be used to seal the cavity wall. Any combustible insulation within the wall must be kept away from the single skin connecting flue pipe by at least 1.5 x its diameter. (Example: diameter 150mm x 1.5 = 225mm distance).

The flue pipe is a push fit over the spigot on the adaptor. Seal off the gap between the flue pipe and wall sleeve with fire proof rope and closing plate.

Clad the flue liners with a minimum of 100mm suitable masonry. A minimum of 15mm light expanded clay aggregate insulation must be installed between the flue liners and masonry. Mix 20 parts light expanded clay aggregate to 1 Part cement and a small amount of water. Ensure it is well mixed before using. 

ALL OPTIONS

Apply Schiedel HT Cement onto the male rebate of the flue liner. 

Position the flue liner on a suitably formed fire gather or support block with the female rebate facing upwards. Arrows on each flue liner indicate the directional flow of flue gases. Continue to apply high temperature cement to each flue liner, cleaning any access material from the joints.

If Bends are required in the chimney make sure adequate support is provided and always backfill with light expanded clay aggregate insulation mix. Liners can be cut between bends to achieve a required offset distance. A steel collar as well as high temperature cement must be used for any cut joints. A maximum of 2 complete offsets (4 bends) are allowed per chimney and the angle must not be greater than 45˚ from the vertical.

SUPPORTING AN OFFSET

The bends and liners that make up an offset must be supported adequately
You must provide adequate clearance from combustible material in accordance with local Building Regulations. Combustible materials must be 200mm from the inner surface of flue liner or 40mm from the outside of the masonry chimney unless it is a floorboard, skirting board, dado or picture rail, mantel-shelf or architrave.

Fit appropriate lead dpc’s and flashings in accordance with the relevant regulations. It is recommend that the lead tray should be dressed up the outside of the flue liners to avoid a weak joint. Weep holes should be provided above the tray for moisture drainage.

Terminate the chimney to the correct height in accordance with local Building Regulations. The chimney can be finished by flaunching (1:3 cement/sharp sand) around a suitable chimney pot. Approved rain caps can be used to help prevent water entering the flue.

AFTER COMPLETION

After installation is complete tests and checks should be carried out in accordance with local Building Regulations. A chimney notice plate must be completed and permanently fixed in the dwelling, ideally near the electrical consumer unit. The checklist and notice plate are available from Schiedel

USE AND MAINTENANCE

The chimney should be swept at least twice a year, once before the heating season and once after the heating season. You may need to sweep during the heating season depending upon use.

Always follow the appliance manufacturer’s operating instructions. Always burn approved fuels or dry seasoned wood. Avoid burning unseasoned wood and slow burning of solid fuels as this can produce excessive soot and condensation which can in turn cause soot fires and damage. If correctly installed, operated and maintained these systems should last the life of the dwelling.