Multiflex® flexible flue liner
Multiflex liners are covered with a 20 year warranty, please click here to download the Topstak Multiflex Warranty Form
Our exclusive Multiflex "Class 1" flexible stainless steel multifuel flue liners are designed to provide a quick and economical solution for improving the safety and efficiency of old chimneys for use with wood, coal, gas or oil burning appliances.
In many situations Multiflex is the best choice for solving common chimney problems.
Multiflex leads the market in terms of quality, proven performance and technical back up. According to chimney specialists and installers across Britain it is the strongest and most flexible liner on the market.
The liners are CE marked with a performance designation which exceeds Building Regulation Requirements and is far better than many other liners. (See specifications below for the full performance designations).
Multiflex protects old chimneys against deterioration and leakage by providing a smooth gastight flue that withstands high temperatures, minimises the risk of tar deposits and warms up quickly to create a strong up draught, allowing stoves and fires to operate efficiently.
Multiflex is the unique name for our exclusive range of liners that are recognised for their high quality, leading specification and performance that many try to copy. Beware of any imitations that attempt to use the Multiflex name, which is a Registered Trademark owned by Topstak Ltd.
The liners are specially designed for quick installation with the minimum of disruption, and their flexibility can cope with bends of up to 45 degree and typical "offset" Victorian chimneys.
A comprehensive range of fittings and adaptors are available to ensure quick installation and easy connection to stoves, boilers, inset and open fires.
We also supply Rockwool preformed insulation pipes and purpose made wraps for insulating the liners in large or cold chimneys.
More details are given in the Multiflex Brochure showing the full range of fittings and installation instructions.
Multiflex approvals and specifications
Multiflex liners have a robust double-skin construction for use with multifuel burning stoves, fires or boilers. The inner wall is designed to provide a smooth gas tight flue for the safe and efficient passage of flue gases. The outer skin has a durable corrugated construction to allow maximum flexibility and strength.
The liners are CE marked and included in the HETAS list of approved products for use with wood and solid fuel appliances. Multiflex liners are covered with a conditional 20 year warranty, please click here to download the warranty form.
There are two grades of Multiflex liner for use with multifuel or wood burning stoves, boilers, open fires and appliances burning gas or oil.
- Multiflex 316 is made from 316 grade stainless Steel. Performance designation is EN 1856-2 T600 N1 W V2 L50010 G
- Multiflex 904 made entirely from 904L grade stainless steel where a higher specification of liner is required. Performance designation is EN 1856-2 T600 N1 W V2 L70010 G
Approvals and certification
CE marked and certified to European Standard EN 1856-2.
Approved by HETAS and included in their list of approved products for use with solid fuel.
Complies with UK Building Regulations.
Performance Designation -A brief explanation
Approved Document J 2010 of the Building Regulations specifies a minimum performance designation of T400 N2 D3 G for flexible flue liners used with solid fuel or wood burning appliances. This means they have to be tested to European Standard EN 1856-2 to prove their performance designation. Multiflex has a far higher designation, which proves its strength, flexibility and resistance to high temperatures.
- T600 means Multiflex has passed testing for a nominal working temperature of 600°C, which gives a better safety margin than the minimum T400.
- N1 means the liners have passed gas tightness testing at DOUBLE the pressure of the minimum N2 requirement. This test is done after the liner is subjected to the flexibility and temperature testing.
- W means the liners are designated suitable for wet operating conditions. V2 shows they have passed tests proving corrosion resistance to the products of combustion from light oil and natural wood. This is far higher than the D3 minimum requirement for dry operating conditions.
- G means our liners have passed the 1000ºC soot fire test and passed the N1 pressure test after exposure to this
Many feel these performance results prove that the design and quality of the Multiflex is far superior to ordinary liners that have the lower designation of a T400 operating temperature and N2 gas tightness test carried out at only 20 Pascal pressure.
We provide a technical and estimating service for our Multiflex liners, so please contact us. Our friendly staff is always pleased to help.
If you have a chimney to reline and want us to help with working out what liner and fittings are needed please download the Chimney Relining Formthat shows the information needed.
Installation services We also offer a supply and installation service in South Wales using our HETAS registered installers based in The Vale Of Glamorgan, Cardiff, Dyfed, Swansea, Monmouyh, Powys and Gwent.
For other areas we have chimney and stove specialists around the UK who stock Multiflex and can offer a local installation service.
Relining Chimney and Building Regulations It is a legal requirement that all relining installations comply with the Building Regulations, which for England and Wales is explained in the Approved Document J. These are minimum requirements aimed at making sure installations are safe.
Most people recommend using a HETAS registered installer to fit a stove and liner. However, you need to be sure that they are covered for this type of work.