Penetrating SIP with Selkirk STC twin wall flue

Penetrating a SIP roof or wall with Selkirk STC twin wall flue.

Prefabricated houses and house components are one way of achieving a very high standard of insulation and air tightness in a building as well as making for a very quick build. Solid Insulated Panels (S.I.P.s) are insulated, pre fabricated constructional panels used to create the walls and roof of a house.

A pumice chimney system is the most suitable chimney system for penetration of a SIP roof, but if you need to penetrate a SIP roof with twin wall flue then here is a method.
An air gap of 50mm to combustibles must always be maintained around the flue.

There must be no mineral wool insulation packed in around the flue pipe.

If this is not the case then flue would no longer be under manufacturers warranty - this might also affect house insurance in the case of a fire.

It is important to maintain the airtightness of the panel.

Where the airtight layer is to be maintained on the outside of the building a Dektite EPDM flashing is installed upside down on the external surface to achieve this air tightness. It is installed upside down so that the profile is reduced as there may need to be a standard lead flashing or similar above the Dekitite flashing. If the airtight layer is inside then the EPDM flashing can be installed on the inside facing down (and painted if necessary).

For further technical advice, chimney and flue design and consultancy please contact us on 0845 226 5754

If you would like us to design your flue system then please go to the flue design service section of this site.