Therma-Tru SHOP 3 Door Preparation - U1 Revised - Manual (Page 7)

Door
Preparation
Shop 3 2014 (U1 REVISED) 3.7
Door Slab Resizing
Door Slab Resizing Beyond Maximum Trimming Limits
Height Resizing
Note:
A standard door can be cut down to any size if it is aesthetically acceptable, the following
procedure for re-railing is followed, and it conforms to the applicable code requirements.
Flush doors and paneled doors may be re-railed. Any height re-sizing beyond maximum
trim limits requires rail replacement. 20-minute steel fire doors can only be resized by a
Warnock Hersey certified re-machiner.
Width Resizing
Doors cannot be edge-trimmed beyond the limits listed in SHOP 3 - Door Slab Trimming
Saw Slab to Length
Measure and mark door slab.
Cut along line with saw, using
carbide-tipped blade. If
available, use panel saw.
Touch up edges with rasp or
sandpaper.
Note: For 20-minute steel fire
doors, a maximum of 6” may be
removed from the bottom of
the door.
Mark for New Rail Pocket
Use new rail as a pattern.
Center rail against cut end
of door slab.
Scribe at rail ends to mark limits
of cut for rail pocket.
Equal
Equal
Scribe line
each end
STOP:
Fiberglass impact doors and 20-minute fiberglass fire doors cannot be re-sized
beyond maximum trimming limits. For 90-minute steel edge fire doors, see
90-minute fire door slab re-sizing section.