Homeowners can update existing interior doors by replacing them with safer, fireproofed doors. These doors are usually made from heavy-grade chip board and are fused with fireproofing resin or solvent. They are thicker than standard interior doors and provide 30 to 60 minutes of fire resistance in case of a fire.
Measure the existing door in multiple places (width and height at the top, middle and bottom) with a tape measure. Purchase a fireproof door and door frame from a local home improvement store or an online source
Remove the existing interior door by pulling out the hinge pins and lifting the door from the frame. Remove the door frame from the door opening in the wall with the prying end of a claw hammer.
Remove the hinge pins from the fireproof door hinges to detach the door from its frame. Fit the new frame into the rough door opening. Nail it in place with a hammer and nails.
Hold the fireproof door in the door frame while lining up the hinges. Slide the hinge pins back into place.
Hinge pins may need to be tapped gently into place with a hammer when hanging the fireproof door. Make sure the door swings smoothly and shuts tightly. The hinges or the door latch may need adjustment if the door is not operating well. An automatic door closer is advised to make sure the door remains closed when not in use to maximise its safety.
Follow any instructions, warnings or precautions that may be included with the fireproof door.