You can upgrade regular doors to fire doors either by using a timber coat or fire varnish.
When using timber coat intumescent paint, the doors should be able to lose about 2 mm to charring without cracking of the thinnest areas and maintaining insulation. The door should also have an additional 2 mm safety allowance.
You should apply at least four layers of paint on both sides of the door. The layers ensure that the integrity and insulation of your structure are not destroyed for about 45 minutes in the event of a fire.
You can also use fire varnish intumescent to upgrade your doors. The varnish is suitable for hardwood doors or solid doors with a hardwood veneer. You may need to apply at least three layers of varnish to achieve 30 minutes of fire resistance.
It is recommended that you fit intumescent strips in the door jambs and around the door perimeter to close the gaps that may allow the fire to pass through.
