Chimneys and Flue Systems

Flue Designs and Specification Service

Orion Heating offer a chimney and flue design service for new builds, renovations and home improvements.

Working directly with architects and the flue manufactures we can assist from the earliest design stages. Avoid unnecessary planning issues by working with Orion Heating to design a correct and safe flue system or chimney.

If your home has no chimney or an old chimney, our Network of Trusted Installers can carry out Free Surveys to discuss the options available to you.

Existing chimneys

Built after 1966 for wood/solid fuel

The Building Regulations for flue systems changed in 1966, after which all chimneys are required to have a Class1 flue installed if intended for solid flue burning.

Class1 flues have an internal liner designed to withstand the high flue temperatures generated by wood and coal, usually this will be a clay or concrete liner built inside the chimney. Today it would ideally be a pumice liner or freestanding insulated flue system.

If your home has a Class1 lined chimney it may not need re-lining. However very large flues installed for big open fires or poorly installed clay liners will need upgrading. A chimney inspection is always recommended before coupling to an existing chimney.

Built before 1966

Typically you will find an unlined brick and mortar chimney in homes built before 1966. Brick and mortar expand and contract at different rates, during use the joints will fail and no longer seal against leaking fumes.

Once a chimney is worked on in any way it must be brought up to current standards. This means installing a Class1 flue system if you intend to burn wood or solid fuel.

Flexible steel liners are used to achieve the Class1 flue standard. High grade stainless steel is heat and corrosion resistant for at least 10 years. With a correctly sized steel flue the fire will work far better than if installed into an oversized brick stack. The flue gasses will move unrestricted and the whole system will reach optimum temperature much faster.

No chimney? No problem!

Option A –  Pumice flue system

Using volcanic pumice from Iceland to construct structural and thermally excellent flues. The Isokern system from Schiedel is designed with outer constructional blocks and inner liners. Built upwards like a Lego tower, it can be free-standing in a timber frame or tied against existing structures.

Alternatively in a brick stack your architect can specify Pumice liners instead of standard clay/terracotta liners. The pumice pipe and Leca insulating backfill offer all the benefits of Isokern but in a standard brick and block chimney stack.

Pumice is the best option when a steel insulated flue may look out of place – or a more substantial chimney structure is desired, but high performance and energy efficiency are most important.

Pumice flue systems can be constructed by your builder or contractor. The extensive fitting instructions and on-site advice available from Schiedel UK make this an ideal service for new builds or architectural projects.
More Info here Schiedel UK, or visit our shop to discuss the options and take away the CD data pack.

Pumice sectional flues are ideally suited to;

  • New build timer frame houses where distance to combustible material and narrow spaces are important
  • Builds where a standard brick and block chimney is specified, but a modern high performance flue is required to pair with a modern woodburning appliance.
  • New homes where flues can be hidden in-between rooms or integrated into walls
  • Home Extensions with a fireplace and requirements for a conventional looking chimney
  • Existing homes with no chimney and space for a high performance flue

Option B – Insulated stainless steel flue

The most popular, and in many homes the easiest way to install a woodburner where there is no chimney.

Connected directly to the stove or fire. These flue pipes can run up and through the roof or out and up the wall (see diagrams opposite). Because they are insulated there is no problem running through rooms or close to the buildings fabric.
Contact Orion Heating to discuss the best flue system for your property. We can work alongside Building Control, architects and builders to achieve the best insulated flue for your project and budget.

The STOVAX Professional XQ – Stove & Fireplace Chimney System combines top performance with a clean and sleek stainless steel finish. For more information see their product website. Orion Heating offer a full design service for Stovax Flue.

Insulated flues offer an immediate and straightforward solution for;

  • Extensions
  • Homes with no chimney
  • Barn conversions
  • Garden office or Summer House
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