Draughtproofing and waterproofness of access hatches

Professional roof access hatches provide the safest way of accessing flat roofs. The roof access hatch covers the recess in the roof construction, forming a direct connection between the shell and the interior of the building.

Just like for recesses in other external partition constructions such as windows and doors, draughtproofing and waterproofness are essential. The pressure exerted by the wind results in a difference in pressure between the internal and external surfaces, causing external moisture to gravitate towards the interior. In light of this, it is crucial that the construction keep out external moisture at all times. This same wind pressure will exert pressure on the hinged lid of the roof access hatch, which may move if not secured.

Sealing roof access hatch

The roof access hatch therefore needs to be fixed on the upstand so that no air can pass through the roof access hatch. The roof access hatch helps to prevent this movement of water in various ways. Of course, it is essential that all hinged constructions such as roof access hatches, windows, or doors be equipped with high-quality and hard-wearing sealing. Staka roof access hatches are waterproofed and made airtight using a high-quality rubber sealing between the upstand and the hinged lid. This rubber is also pressed in evenly by the strong stainless steel hinges and the two-point closure.

Alongside this, a Staka roof access hatch is equipped with draining edges on the top of the upstand. These edges are on all sides of the upstand, meaning water cannot build up to reach the lid and creating an excellent barrier up to which the roofing material can be laid against the upstand.

Tested access hatch

To guarantee the windproofness and watertightness of a Staka roof access hatch, the roof access hatch must undergo and pass relevant tests. The windproofness and waterproofness of a Staka roof access hatch is tested by SKG. Both aspects also play a crucial role in passing the KOMO assessment. The assessment involves a 'test case' on which the roof access hatch is mounted. In order to simulate a natural situation, pressure from above and below is applied to the roof access hatch. The test then investigates whether any air passes through during the time this pressure is applied. The same pressure is applied when the roof access hatch is sprayed with water. The test is carried out according to the NEN 3661 and NEN 2778 standards, and establishes whether a Staka roof access hatch is windproof and waterproof and meets the requirements of the Dutch Buildings Decree.