Finding your feet
Finding the right roof hatch to meet your requirements is important to ensure a safe means of access is always provided. With such a wide variety of roof hatch types it may seem daunting at first to know what you need. Whether it is for just for maintenance or to facilitate the installation of equipment into or out of the building. Other common applications for roof hatches include factories, office buildings, shopping centres, storage facilities, and non-residential buildings that require access to the roof area. Sizes mentioned in this article refer to the structural opening which is the hole within the roof.
What is a roof hatch?
Roof hatches are horizontal doors that provide access to the roof through a roof opening. The roof is often accessed via a fixed ladder, ships staircase or retractable ladders with a hatch at the top. The ceiling height often determines the size of roof hatch required as different heights require different means of access.
Retractable ladders are suitable for up to 3.5m however require a minimum opening of 900 x 750. Ships type ladders are more heavily regulated so require a minimum headroom clearance (Clear space from the angle of the ladder) of 1200mm. Fixed ladders can be used with smaller size roof hatches such as 750 x 750 providing the ceiling height is no more than 2.5 metres. Ceilings higher then this will require a cage on the ladder.
Roof access for individuals often falls within this category. Ideal for general maintenance and repairs on a roof, these hatches are generally smaller starting from 600 x 600 as a minimum recommended size (It is important to consider how the roof would be accessed at this size) moving upwards towards the more recommended size of 900 x 750. This size allows adequate space to access with ease and also provides enough space to use with most ladders.
Access hatches for equipment usage are generally larger sizes specified as double leaf covers often offered as bespoke manufactured to custom sizes. Electric operation or manual assisted opening is available depending on size. Electric operation can be operated using a wall switch at the bottom of a staircase for easy access when carrying heavy equipment. The application and area should be considered as coastal regions may require the use of stainless steel materials to avoid erosion.
Traditional roof hatches open vertically using actuators or springs, these are ideal in the majority of applications due to ease of use and cost effectiveness.
A sliding roof hatch differs due to its horizontal sliding mechanism. Using internal telescopic rails or external fixed rails, the hatches open horizontally providing the maximum amount of clear opening with no hold open stays or actuators obstructing the space. Tall buildings with high wind loads, buildings or floor with restricted head spaces all benefit from sliding roof hatches.
They can be offered as glazed lids which are ideal for accessing roof terraces and green roof spaces as a unique architectural aspect. Sliding roof hatches are perfect along with a staircase of ships ladder due to the large clear opening.
Most roof hatches should be thermally broken and insulated, generally they may come with off the shelf insulation which provides adequate thermal performance but what happens if ‘adequate’ does not quite cut it? Superior insulation can be specified which uses specially designed insulation components to offer a superior U-value then standard insulation. This is ideal in specialised applications such as cold stores and highly energy efficient buildings where every improvement on insulation is required to meet increasingly stringent energy saving goals.
Most roof hatches are sold with an existing upstand to be installed on a new roof. However, some applications may involve renovating old roofs and damaged/old roof hatches. A low profile replacement hatch is perfect for retrofitting into existing systems. These covers mount directly on top of the existing curb/upstand once the old hatch is removed. The hatch comes to the edge of the curb to ensure weather tightness
In conclusion the importance of specifying the correct roof hatch is crucial to ensure a safe means of access is provided. Contractors should consider the intended purpose of the roof hatch, facility and requirements. Where further information is required manufacturers can assist in the specification process and identify a suitable product to meet requirements.
|Personnel Roof Hatch||Equipment roof access||Sliding roof hatch||Superior Insulation||Retrofit|
|Single Leaf Manual Opening||Double leaf electric operation||Manual sliding or electric||Manual Opening||Manual Opening|
|Ideal for single person without tools or equipment||Provides a larger area to access with equipment and tools||Provides maximum clear opening for a variety of uses||Individual access||Individual access|
|Smaller sizes kept in stock||Bespoke made to order to almost any size||Bespoke sizes||Smaller stock sizes||Small stock sizes|
|Sizes above 900 x 750 available with select ladders||Most ladders are suitable for these sizes||Ladders and stairways are compatible||Sizes above 900 x 750 available with select ladders||Roof structure dependnet|
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