Examine & upgrade existing doors in listed buildings
Examine & upgrade existing doors in listed buildings
Remove and examine the following doors to be protected and re-used. Remove beads, fill any cracks or splits and voids in the door panels and between the edge of panels and the frame with intumescent paste such as Masterseal. Apply Fireface fire resistant membranes to plain, painted or varnished surfaces free from flaking or peeling (if polished, then strip back to the original timber surface). Cut Fireface to size of panel and adhere with a recommended adhesive:
Sealmaster Fireface Contact adhesive with accelerator: apply to both surfaces with applicator supplied, and as soon as dry to touch, bring surfaces together with firm pressure 2. A water based PVA woodworking adhesive (Resin W or similar). Follow manufacturer’s instructions, havinf stripped all paint or varnish from panel, and clamp Fireface must be clamped to panel until adhesive has cured 3. Urea formaldehyde resin such as Dynochem aerilote KL + CHS hardener, comprising a resin and acid catalyst. Remove paint and varnish from panel and apply resin thinly to one surface, and the acid to the other, and clamped together until the bond is effected.
If when the beads are removed, the panel is seen to be retained in a groove in stiles and rails, cut Fireface to allow 2mm gap to all edges.
Refit beads, bedding onto Masterseal so that they are bonded to the stiles, rails or muntins, but not the panels. Pin at 150mm centres with 40mm steel pins at 250 – 350 inclination. Do not pin through the panel, or stick the beads to the panels as the panels may split.
On completion door to be close fitting with frame (maximum gap 4mm) and effectively self-closing to engage the latch. The bottom edge of the door should be parallel to the floor finish so as not to bind and to leave a maximum gap of 10mm beneath the door when closed. It is recommended that an overhead hydraulic closer is used. Hang on three steel or brass hinges with hinge blade size of 75-100mm by 27-33mm. The doors or frames are to be fitted down both jambs and along the head with intumescent strips and cold smoke seals. The latch should have a positive latching mechanism comprising steel or brass nib (not rollerball catch) which is preferably surface mounted, secured to the door with fixings to a minimum depth of 25mm. Any lock, including deadlock, must be fitted with a turnkey mechanism, not necessitating use of a key on the room side.
The doors are to be fitted in accordance with guidance issued by the Timber Research and Development Association. All works to be in accordance with Appendix I to this schedule. On completion doors/frames to have a minimum fire resistance of 30 minutes.