Spiral Access Doors

The products below cover duct sizes from 100mm to 500mm, with the access-door dimensions changing according to the diameter of the ductwork.

Important: This information is general. Product selection depends on duct diameter and the requirements of the wider system. If you are unsure which access door you need, speak to our team before ordering.

Duct Access Doors for Spiral and Round Ductwork

A duct access door provides a removable opening into a section of ductwork. This allows the inside of the duct to be accessed without removing complete sections of the duct run.

The access doors in this category are manufactured from galvanised steel and are shaped for use with round spiral ducting. Different door sizes are available to suit different duct diameters, so both measurements need to be considered when choosing a product.

Product Details at a Glance

• Product type: Spiral/round duct access door
• Material: Galvanised steel
• Small door: 180mm × 80mm
• Medium door: 250mm × 150mm
• Large door: 400mm × 300mm
• Duct sizes covered on this page: 100mm to 500mm
• Application: Access into spiral ductwork for inspection, cleaning and maintenance

Access Door Sizes and Duct Compatibility

The dimensions of the access door and the diameter of the ductwork are separate measurements. For example, a 250mm × 150mm door can be supplied in versions shaped to fit several different duct diameters.

The current range includes:

• 180mm × 80mm small access door – to fit 100mm / 125mm duct
• 250mm × 150mm medium access doors – to fit duct sizes from 150/160mm through to 350/355mm
• 400mm × 300mm large access doors – to fit 400mm, 450mm and 500mm duct

Check both the access-door size and the stated duct diameter before ordering.

Spiral Duct Access Door Adapters

We also stock spiral duct access door adapters for customers who need a prepared duct section for an access door.

These are separate sections of spiral ducting supplied with the access-door opening already cut. The access door itself is sold separately, so the adapter and door sizes need to correspond.

Access door adapters are available across a range of duct diameters and can be purchased separately from the access doors shown below.

Frequently Asked Questions

What is the main purpose of a duct access door?

A duct access door provides a removable opening into ductwork so the inside of the duct can be reached for inspection, cleaning or maintenance.

What is the difference between a spiral access door and an access door adapter?

The access door is the removable door itself. An access door adapter is a prepared section of ducting with the opening for the access door already cut into it; the access door is purchased separately.

How do I know what size access door I need for my spiral ducting?

Start with the diameter of your ductwork, then choose the access-door product listed for that diameter. The same physical door size can be supplied for several different duct diameters, so always check the complete product description.

What sizes of spiral access doors are available?

The range on this page includes 180 × 80mm, 250 × 150mm and 400 × 300mm access doors, with versions available for spiral duct diameters from 100mm to 500mm.

Are these duct access doors made from galvanised steel?

Yes. The spiral access doors in this category are listed as galvanised-steel products.

Are these duct access doors fire-rated or insulated?

Fire-rating or insulation properties are not stated for the standard access doors in this category. If your project requires a specific fire, thermal or other performance classification, confirm the requirements before ordering.