A common issue at time of fire door certification and inspections of hinged & pivoted fire doors are floor threshold related items. This guideline outlines Australian Standards and best practices for the selection, design and installation of fire door thresholds to meet compliance.
AS Standards AS1905:2005 & AS1905:2015 – SECTION 5 Clearances Around Doors Leaves
Clearances between the bottom of all door leaves and the floor shall be as follows:
a) Between the leaf and the top surface of the floor including and floor covering.
Not less than 3mm and not more than 10mm
b) Between the leaf and the top of the non-combustible threshold – not more than 25mm
NOTE: When the installed door set is inspected for compliance with Item (b), the clearance should not exceed 25mm for the purpose of the certification unless a note providing information on clearance is made in the evidence of compliance.
The Non-Combustible Threshold under a Fire Resistant Doorset
- The floor surface, either the non-combustible threshold or the floor covering shall be sufficiently flat and level so when a fire resistant doorset is installed, it can operate unhindered and with a compliant clearance when in the closed position.
- Lifting and levelling the top of fire rated door frames may leave a large gap under the door and frame jamb.
- Consider the fire resistance required to be compliant
- Level the floor to enable compliance
- Any excessive hollows or bumps in the floor that could compromise the fire resistant doorset installation shall be rectified before certification.
- Level the floor between jambs
- Level the hollow in the floor
- Rectify the bump in the floor
The Non‐Combustible Threshold and floor finish within the door swing zone.
- The floor surface, either the non-combustible threshold or the floor covering shall be sufficiently flat and level so when a fire resistant doorset is in operation it can operate unhindered without binding on any part of the floor within the door swing zone.
- Check for any bump or rise in the floor
- Check for any slope in the floor
- Uneven floors should be rectified by the trade responsible
- Trimming the bottom of the door leaf to accommodate uneven floors could render the fire door non-compliant when in the closed position.
- Determine your options before you proceed
Floor Covering Designs
When designing and setting out for floor finishes in fire door thresholds it is imperative to deliver a design that meets not only aesthetics & functionality but compliance to Australian Standards.
- Floor Finish under the Fire Door leaf and the Direction of Swing should the same material.
- Floor Finish across the Fire Door Threshold should be level right through without rises or dips. (Image A)
- Floor Finish should be level across swing arc direction should be lever right through the (Image B)
Drop Seals
Drop seals are an additional item not required for fire compliance but are generally used for smoke, acoustics, draft, energy efficiency and vermin. All items fitted to a Fire Door must be tested to Australian Standards and the fire core used in the construction of the Fire Door.
- Ensure the Drop Seal is Fire Rated to Australian Standards and the Manufactured Core.
- Fire Rated Drop Seals do not eliminate the requirement to achieve – Not less than 3mm and not more than 10mm under the door leaf.
- Uneven floor finished threshold can hinder the functionality of the Fire Rated Drop Seal.
Poor floor threshold installations can cause the fire resistance to be compromised and could directly increase costs at time of construction for rectification works.
If you require additional advice on Fire Door installations and certification requirements contact our team
