Sectional Overhead Door Safety Devices

The graphic below shows optional safety devices for Sectional Overhead Doors. 

Under current UK and European legislation, Safety brakes and Spring break safety devices should be fitted to all overhead sectional doors.

Choosing the right type of industrial door

When choosing to replace or install a new industrial door, the choices can be overwhelming if you don't understand the options available to you.

Here is a short guide to the types of industrial door that are available and situations where they are appropriate to use.

Sectional Overhead Doors

Sectional Overhead doors are made from panels that are typically 610mm in height. Individual panels are connected together with a hinged brackets.

Typically, each panel is formed from two aluminum outer panels with insulating foam, injected between them. This gives a high degree of strength as well as extremely good insulating properties.

The number of sections required in a door will depend on the height of the door opening.

The doors are fitted in guide rails that run up each side of the door opening and continue up around on tracks that are suspended from the building roof. The angle of the track can be up to 90 degrees from the door opening. This track angle will depend on the height of the roof available above the door opening.

Sectional doors are raised and lowered by cables, one attached to each end of the bottom panel of the door. When the door is raised, the cables are wound onto barrels at each end of a shaft, normally mounted above the door opening, that rotates during the operation.

Tensioned springs, on the shaft, are the driving force for the door opener.

Depending on the height of the door opening, sectional doors can take some time to open, so are therefore best suited for low traffic openings, or situations where the door will remain open for prolonged periods of time.

Sectional doors can be operated manually or electrically. For manual operation, a chain is attached to the end of the shaft and the operator pulls the chain through a gear system that rotates the shaft. Manual operation is mostly recommended where the doors are not frequently used and where the height of the door is not excessive, making it difficult to open due to it's overall weight.

Electrically operated sectional doors are used where the weight of the door makes manual opening difficult, or where the door is operated frequently throughout the day. The motors can be either single or 3 phase, depending on the available on-site electricity supply and the weight of the door.

Wicket doors

Wicket doors are personnel doors that are built into the main sectional door. These allow people to enter or exit the building without the sectional door being opened.

Wicket doors must be closed when the main door is operated, and safety devices are available that will prevent the door for operating should the wicket door be open when it is operated.

Advantages/Disadvantage

Very high thermal insulating properties, sectional overhead doors are a great solution where the door is not operated frequently throughout the day.

Disadvantage

Because of the way that sectional doors open and close on tracks, there is a need to have enough space for the tracks to run into. Depending on the height of the door, this could be up to 8 meters of track behind the door opening. If the structure of the building does not allow this, a sectional door may not be the best solution for your building, a roller shutter may be a better choice.

Roller shutter doors

The panels (known as Lath) of a roller shutter door, are on average 65 mm in height. This allows the door to wrap around a barrel at the top of the door, therefore roller shutter doors are a good solution where the height above  the door is limited or too high to suspend the tracks necessary for a sectional door.

Individual lath are generally made from of  aluminum or steel sheet, pressed to form the required shape. As such, they present a poor thermal rating, and as there is generally no seals around the door, wind and weather can come in through the door.

Insulated lath are available, that provide a much better thermal barrier that a standard lath.

The lath are held together by end plates (known as end locks) fitted at alternate lath at the ends. The end locks run in a guide rail either side of the door opening.

Unlike sectional doors, the individual lath on a roller shutter link together along the whole edge of the lath.

As the lath wrap around a central barrel, springs and cables are not required.

Roller shutters can be operated manually via a chain, or electrically by single or 3 phase motors.

Advantages

Roller shutter doors require less above door space than a sectional door and because the individual lath can be easily replaced, are less costly to maintain than sectional doors.

Disadvantages

Much lower thermal barrier capabilities than a sectional door.

Fire Resistant Roller Shutters

Fire Resistant Roller Shutter Doors are for internal use, in order to isolate one part of a building from another to prevent the rapid spread of fire.

In most applications, fire rated roller shutters are open for the majority of the time. They operate automatically when a fire is detected. This can be via a fuseable link, or they can be linked to fire alarm systems.

Depending on the model of Fire resistant roller shutter used, they can be rated to withstand fire for 2 to 4 hours.

In order to prevent the spread of fire, the structure surrounding the door opening must be adequate to not only hold the weight of the door, but also to be fire rated, to prevent the spread of fire around the door.

Rapid rise doors

Rapid rise doors are named such because they open in just a few seconds. In fact a rapid rise door can be open at a rate of 1 meter per second, making then an ideal door for automatically opening when a fork lift truck approaches, allowing very quick egress through the opening.

They then close, at a slower rate, once the  opening is again clear.

The main curtain of a rapid rise door is a made from a neoprene sheet.

There are two main kinds of rapid rise doors, roller and folding.

Similar to a sectional door, folding rapid rise doors are made from individual panels that fold into the upper space when they are operated. These doors use webbing belts that are attached to a barrel across the top of the door to wind the door up and down.

Roll up rapid rise doors are an ideal solution where it is necessary to keep internal sections of a building environmentally separate, but allow fast passage of goods or people.

Rapid rise doors are also a good solution to prevent the ingress of pests in a food manufacturing environment.

Rapid rise doors are electrically operated and can be activated by push switches, remote control transmitters or radar movement detection systems.

Combinations of doors

Where the situation is that there is a need for a secure external door when the building is vacant, yet a high level of traffic bringing goods in and out of the building during working hours, a combination of doors can be used.

For instance, a sectional overhead door can be fitted to provide the required out of hours security, and an inner rapid rise door is used during working hours to allow the fast movement of goods, whilst giving a degree of weather and environmental shielding.

This can also done internally, where a rapid roll door can be used on one side of a wall opening in normal working hours providing an environmental shield between sections of a building, with a fire rated shutter on the other side to prevent the spread of fire.

About

Anglia Door Systems Ltd provide supply, installation, industrial door maintenance, industrial and commercial door repair to a wide variety of business sectors including warehousing, factories, office buildings, schools, care homes, clincs, surgerys, hospitals, motor tarde showrooms, industrial units, shops and retail premises, throughout the East Anglia area of the UK.