Schiedel ISOKERN DM

DM Double Module Chimney System

When the ease of construction and maximum insulation matter then the Double Module System comes into its own. This chimney system is designed to be quick and easy to install.

The lightweight blocks are easy to handle. The outer and inner blocks are laid at the same time but with staggered joints for safety and stability. The double layer of pumice separated by an air gap maximises the chimney insulation.

The Pumice chimney systems are suitable for wood logs, solid fuel, oil and gas (not suitable for condensing appliances).

Isokern DM

There are 3 systems covering a range of different internal diameters to meet the requirements of different appliances and uses:

DM 36
150mm internal diameter for smaller output inserts stoves and solid fuel/oil cookers
DM 44
180mm and 200mm internal diameters for inserts, stoves and small open fires
DM 54
300mm and 345mm internal diameters for Magnum fire chests, larger appliances and open fires.

Features

Unique Features of the Isokern DM system

  • Zero distance to combustibles on straight rendered chimneys (when using top ring terminal)
  • Quick and easy to assemble
  • Lightweight materials, easy to handle
  • Highly insulating pumice for better draw and minimum heat loss
  • Staggered joints for maximum safety and stability
  • Air gaps between outer casing and flue prevents surface staining
  • Good resistance to temperature variations gives the maximum performance for your appliance.
  • CE Certified to EN1858 with the designation T450, NI, D, 3, G (00).

Technical Specification

DM36

DM 36 is designed for smaller output inserts, stoves and cookers.

Isokern DM
Isokern DM
DM44

DM 44 is designed for inserts, stoves and small open fires.

Available in 2 internal diameters, 180mm and 200mm. All inner blocks fit into the same external block.

Isokern DM
DM54

DM 54 for larger open fires and appliances.

Available in internal diameters Ø300mm and Ø345mm. Both inner liners fit into the same external block size.

Isokern DM

Applications

Construction begins by providing a suitable foundation and constructional hearth in accordance with Building Regulations and site requirements.
Click the links mentioned below for details about a particular installations.

Open Fire Option
  • Bed the base plate of the firechest onto a suitable foundation/constructional hearth in accordance with Building Regulations and at the level required on site using Isokern Lip Glue.
  • Install the firechest using lip glue making sure all elements are level. 100mm of brick/blockwork must be built around the sides and back of the firechest to comply with Building Regulations. The inside of the firechest must be finished with a suitable fireback or firebrick slips.
  • Install the gather using lip glue making sure all the elements are level. The front face of the gather can be finished with platerboard, rendered or clad in masonry. Lintels may be required above the gather to help carry the brick or blockwork. The maximum loading capacity of the ISOKERN firechest and gather is 2500kg.
Isokern DM
Stove In Recess Option
  • Pre-stressed lintels or a suitable cast-in-situ concrete slab must be provided above the stove recess,please make sure they are strong enough to carry the load(see appropriate Isokern DM drawing for aperture size). It is recommended to have a minimum of 600mm of stove flue pipe before connecting to the support block.
  • The support block is bedded onto the lintels using a weak mix mortar. A stainless steel adaptor is used to create a positive connection from the support blcok to the stove flue pipe(fibre rope should be used to create a seal).
Isokern DM
Free Standing Stove
  • A soot door casing and access flue block must be used below the flue pipe entry.
  • The DM 45° access kit is then used for the connecting flue pipe
  • A suitable wall sleeve must be used to seal the cavity wall.
  • Any combustible insulation within the wall must then be kept away from the single wall connecting flue pipe by at least 1.5 X its diameter.
  • Fibre rope is used to seal between the flue pipe and wall sleeve , a suitable trim collar can be used to finish the inner wall surface.
Isokern DM
Chimney Construction
  • Bed the first outer casing using lip glue making sure the rebate (raised lip) is uppermost.
  • The starter flue block is then put inside the casing bedded with lip glue.
  • The socket on the starter flue block must be uppermost and the air gap between the starter flue and the casing should be kept clear.
  • The finished lip glue joints should be 2-3mm thick, a special bag is provided for ease of application and the lip glue should be applied in 12-15 mm beads.
Isokern DM
  • Casings and flue blocks are added using lip glue for all joints. Ensure the air gap between the inner and outer casing remains clear.
  • The outer surface of the casings to be finished with plasterboard on dabs or plaster.
  • The side that faces the wall does not need an external finish.
Isokern DM
  • Offset blocks ‘if required’ must be used immediately above the support block or firechest gather. They must be glued together with lip glue and be fully supported.
  • Please note a chimney should be built straight wherever possible. A starter flue block will be required above the offset blocks to stagger the joints between the outer casing and inner flue blocks .
Isokern DM
  • On a rendered stack with top ring fitted , where a straight chimney passes though a floor or roof, zero mm distance to combustibles can be applied.
  • A sliding joint is made using mineral wool or similar non-combustible material.
  • In all other cases ,38mm clearance must be maintained between the outer face of the chimney and any structural timber or loose combustible material . Floor boards ,skirting boards ,dado rails and other non -structural components may, however ,be in contact with the chimney.
Isokern DM
  • External chimneys must be tied to the structure at maximum intervals of 1.5 m and at the point where it departs from the roof using 2 x suitable stainless stell wall ties.
  • These are fitted into the outer casing joints. They are not always required for internal chimneys .Please consult our team at the Isokern technical office.
Isokern DM
  • High tensile steel reinforcement rods will be required for all chimneys with a height that exceeds 1.4 m above the roof line, 1.1 m if the wind speed exceeds 44ms.
  • These rods are available from Isokern and must be grouted (1:3 cement/sand) into the holes provided in the outer casings.
  • You must start the rods at least the same height below the roof as what’s above ,please check with our technical department.
Isokern DM
Rendered Stack Option
  • Code 4 lead flashing to be fitted at roof level as per Building Regulations. We recommend that you scorch a 5-10 mm deep channel into the outer surface of the casings and fold in the top edge of the flashing .
  • Finish the outer surface of the casings above the roof with 2 part waterproof render.
  • The recommended mix is 1:2:5-6 cement:lime:sand for the undercoats.1:2:8-9 cement:lime:sand for the final coat.
  • The number of coats required will depend upon the degree of exposure, generally a two coat mix is acceptable.
  • The mix may very due to climate conditions ,the thickness of any one coat should not exceed 15 mm and each subsequent coat should be reduced by approximately 3 mm
  • Isokern concrete capping for render to be lip glued onto the last casing .
Isokern DM
Brick Stack Option
  • To take brick or stonework externally a corbel is fitted just below the roof.
  • Use trusses and trimmers to brace the cladding as it passes through the roof
  • Code 4 lead tray with 50 mm upstands and stepped flashing to be fitted in accordance with Building Regulations .
  • A 50 mm upstand should be fitted tight to the outside of the flue block  and where possible turned in by approx 10 mm.
  • Lead trays should be coated with bituminous paint where it is in contact with mortar.
  • The D.P.C tray should be fitted at least 150 mm above the lowest point of intersection with the roof.
  • Weep holes should be provided at the front of the stack above the tray for water drainage .
  • Casings can be deleted above the corbel if stack height is less than 1.4 m above the roof.
Isokern DM
Termination

Option 1 – Raincap Ventilated Option (installation with 0 distance to combustibles for straight rendered chimneys only)

  • Take the last flue block up through the capping ,do not fill the gap between the flue block and capping.
  • Push fit the aluminium top ring onto the flue block and make sure there is a 10 mm air gap between the outer edge of the ring and the capping .
  • The flue block may need cutting to suit.

Option 2 : Chimney Pot Option

  • This option always required a 38mm distance to combustibles from the outside of the block .
  • Fit a chimney pot at least 75mm down into the capping and flaunch with 1:3 cement and sharp sand to seal around .
  • This option is not possible if 0 distance to combustibles is required.
After Completion
  • After installation is complete, tests and checks should be carried out in accordance with document J of the 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 Isokern.
Use & Maintenance
  • The chimney should be left for at least 72 hours before use , then start only with small fires for the first week and gently increase thereafter.
  • 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.
  • The brush should be a medium density polypropylene bristle type and should be the same diameter as the flue. Steel brushes must not be used to sweep the Isokern pumice flues
  • 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 product excessive soot and condensation which in turn cause soot fires and damage.
  • If correctly installed, operated and maintained these systems should last the life of the dwelling.

Components & Systems

DM 36 - for smaller output inserts, stoves and cookers

All Dimensions are external unless otherwise stated
SAP Code Description Weight (kg)
 
Isokern DM
130714 360mm square casing 250mm high 15
Isokern DM
130712 360mm square access casing 250mm high (150mm i/d access hole) 13
Isokern DM
130713 360mm square casing & soot door 250mm high 18
Isokern DM
130709 DM36 45º flue entry kit (four parts) 500mm high 42
Isokern DM
126363 150mm i/d 255 x 255 starter flue block 125mm high 4
Isokern DM
126369 150mm i/d 255×255 flue block 250mm high 8
Isokern DM
126368 150mm i/d 255×255 access flue block 500mm high (177mm i/d access hole) 16
Isokern DM
130715 570mm square corbel for brickwork 75mm high 32
Isokern DM
130710
130711
490mm square capping – render
690mm square capping – brickwork
13
31
Isokern DM
126378 150mm i/d 360 x 435 offset block (86mm, 30˚ offset) 150mm high
(allow 38mm distance to combustibles on offset chimneys)
25
Isokern DM
130716 150mm i/d 360 square support block 100mm high 15
Isokern DM
126373 150mm i/d (205mm o/d) stainless steel adaptor
Isokern DM
126357 125-150mm i/d (205mm o/d) stainless steel decreaser adaptor
Isokern DM
135070 Top Ring (for ventilation)
Isokern DM
130732 Raincap (with fixing rods for top ring)

DM 44 - for inserts, stoves and small open fires

All Dimensions are external unless otherwise stated
SAP Code Description Weight (kg)
Isokern DM
130727 440mm square casing 300mm high 30
Isokern DM
130725 440mm square access casing 300mm high (220mm i/d access hole) 29
Isokern DM
130726 440mm square casing & soot door 300mm high 36
Isokern DM
130719 440mm 180mm i/d 45˚ flue pipe entry kit (4 parts) 600mm high 86
130722 440mm 200mm i/d 45˚ flue pipe entry kit (4 parts) 600mm high 84
Isokern DM
130720 180mm i/d 310 x 310 starter flue block 150mm high 8
127684 200mm i/d 310 x 310 starter flue block 150mm high 6
Isokern DM
127068 180mm i/d 310 x 310 flue block 300mm high 15
127683 200mm i/d 310 x 310 flue block 300mm high 14
Isokern DM
130717 180mm i/d flue 310 x 310 access block 600mm high 28
127682 200mm i/d flue 310 x 310 access block 600mm high 28
Isokern DM
130728 650mm square corbel for brickwork 75mm high 40
130235 650 x 560mm offset corbel for brickwork 75mm high 34
Isokern DM
130818 740mm T corbel for external brickwork 75mm high 47
Isokern DM
130723 570mm square capping for render 18
130724 820mm square capping for brickwork 44
Isokern DM
131810 180mm i/d 440 x 500 offset block (56mm, 30˚ offset) 100mm high 22
130718 180mm i/d 440 x 500 offset block (86mm, 30˚ offset) 150mm high 22
127686 200mm i/d 440 x 500 offset block (56mm, 30˚ offset) 100mm high 20
127687 200mm i/d 440 x 500 offset block (86mm, 30˚ offset) 150mm high
(Allow 38mm distance to combustibles on offset chimneys)
30
Isokern DM
130721 180mm i/d 440mm square support block 100mm high 22
130730 200mm i/d 440mm square support block 100mm high 20
Isokern DM
127691 200mm i/d (255mm o/d) stainless steel adaptor
Isokern DM
127671 150-200mm i/d (255mm o/d) stainless steel decreaser adaptor
127672 175-200mm i/d (255mm o/d) stainless steel decreaser adaptor
Isokern DM
130675 Top Ring (for ventilation)
Isokern DM
130732 Raincap (with fixing rods for top ring)

DM 54 - for larger open fires and appliances

All Dimensions are external unless otherwise stated
SAP Code Description Weight (kg)
Isokern DM
130708 545mm square casing 300mm high 40
Isokern DM
129031 300mm i/d 420 x 420 starter flue block 150mm high 11
129093 345mm i/d 420 x 420 starter flue block 150mm high 11
Isokern DM
129033 300mm i/d 420 x 420 flue block 300mm high 22
129094 345mm i/d 420 x 420 flue block 300mm high 22
Isokern DM
130735 800mm square corbel for brickwork 75mm high 57
Isokern DM
130733 670mm square capping for render 20
130734 950mm square capping for brickwork 46
Isokern DM
129038 300mm i/d 545 x 635 offset block (86mm, 30˚ offset) 150mm high 44
129092 345mm i/d 545 x 635 offset block (86mm, 30˚ offset) 150mm high
(allow 38mm distance to combustibles on offset chimneys)
40
Isokern DM
129043 300mm i/d 545mm square support block 100mm high 30
Isokern DM
129039 300mm i/d (365mm o/d) stainless steel adaptor
Isokern DM
135093 Top Ring (for ventilation)
Isokern DM
130732 Raincap (with fixing rods for top ring)

DM Accessories

All Dimensions are external unless otherwise stated
SAP Code Description Weight (kg)
Isokern DM
146432 1500 x 2015 x 70mm support lintel
Max load (per pair) 1650kg
51
Isokern DM
130689 Stainless steel casing wall tie
Isokern DM
130771 Lip glue (5kg) 5
Isokern DM
102629 1m reinforcement rod 12mm diameter 1

Downloads

Pumice Brochure

Pumice Brochure

8.12 MB

Isokern Approvals & Certificates

Isokern Approvals & Certificates

96.21 KB

Videos

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External Double Module with Ignis Protect
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