Certified airtight and pre-insulated attic door from Wellhofer.
- Certified airtight (Class 4 airtightness) and pre -insulated attic door providing homeowners and specifiers with the optimum level of thermal performance and airtightness.
- Certified and tested under extreme climate conditions equivalent to that required for external doors on buildings; to EN 1121.
- Ideal for both new build and retrofit projects
- Independent airtightness sealing system which seals the hatch frame to the surrounding timber joists, noggins or the adjacent airtightness and vapour control layer.
- The airtight seal of the hatch door is maintained by means of a pre-stressed spring which ensures the door remains airtight, even when a blower door test is carried out. This spring is full adjustable to the homeowner’s requirements.
- Airtightness is 5 times better than that required by DIN 4108-2 and is certified to EN 1026:200-09.
- The hatch also has a U value of 0.58W/m2k certified to EN ISO 12567 – 1: 2001/02. It should be noted that this U value is for a single optimum position in the centre of the door, not the installed value.
- A Passivhaus-certified option is also available (please get in touch)
- Airtightness Products Pricelist
|Standard Size||(size of ceiling opening in cms)|
|Finished Measurement||The finished measurement of the casing is 1.5 cm smaller in length and width than the ceiling.|
|Attic Ladders||The Wellhofer 4D is supplied with a ladder which has a floor to ceiling height of 2570-2680 mm.|
|U Value||0.58 (not installed value)|
A smaller certified airtight pre insulated access hatch is also available (600 x 600mm).
Alternative dimensions are also available on request.
|Wellhofer Certified Airtight Attic Hatch WS4D||Datasheets||Download|
|Wellhofer AIRTIGHT ATTIC HATCH WS4D Technical Drawings 1200 x 600 x 250mm||Datasheets||Download|
|Installation Guide Wellhofer Attic Hatch||Datasheets||Download|
|Additional Guidance Attic Hatch Installation||Datasheets||Download|
|GBS Airtightness Price List April 2018||Pricelist||Download|