Wellhofer Airtight Attic Hatch

Product Description

  • The Wellhöfer 4D attic hatch not only features a certified airtight and pre insulated attic door, but also features an independent airtightness sealing system which seals the hatch frame to the surrounding timber joists, noggins or the adjacent airtightness and vapour control layer.

  • The hatch door is not only 3rd party certified airtight door, but the additional hatch frame sealing system has also received 3rd party airtightness certification. The system has been used in many buildings achieving low energy and even Passivhaus levels of performance for airtightness.

Wellhofer Attic Hatch


  • Therefore one cannot underestimate the importance of not only installing an airtight and adequately insulated attic hatch, but also to ensure the frame is also installed airtightly.
  • 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. The airtightness of Wellhöfer 4D is 5 times better than that required by DIN 4108-2 and is certified to EN 1026:200-09.

  • The complete hatch also features a low U value of 0.78W/m2k certified to EN ISO 12567 – 1: 2001/02.

  • It should be noted that this U value is for the complete system rather than a single optimum position in the centre of the door.

  • When specifying a truly airtight attic hatch one should ensure not only that the door is airtight, but also, the means by which the attic hatch’s frame is sealed to the adjoining vapour control layer or timber noggin.

  • One may install an attic hatch which has an airtight door, yet, the leakage area between the frame and the surrounding noggin can lead to an additional 70-100 litres of heating oil required per year.
  • The Wellhöfer 4D attic hatch and ladder provides homeowners and specifiers with the optimum level of thermal performance and airtightness.
  • The long term durability of an attic hatch is critically important. In recognition of how cold and humid an attic void can become in winter, Wellhöfer have certified and tested the 4D hatch under extreme climate conditions equivalent to that required for external doors on buildings; to EN 1121
  • The Wellhöfer 4D hatch and ladder are ideal for both new build and retrofit projects.  Wellhöfer 4D airtight attic hatch is supplied in a standard 1200x 600mm and 1300 x 600mm dimensions

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Technical Detail


Standard Size (size of ceiling opening in cms)
Length 120
Width 60
Height 25
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 2570-2680mm.
U Value 0.78



Attic stairs according to EN 14975 do not fall under construction products guideline
and/or Construction Products Regulation
Therefore no CE mark based a declaration of performance is needed

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