Therma-Tru’s line of 20-minute rated doors look very similar to other designs available, however the construction of these doors differs slightly. They still have a polyurethane foam core but it is fire-rated to withstand 20 minutes of fire exposure.
Along the lock side is a piece of full length blocking and additional blocking for panic and closure applications if necessary. The edges are made of laminated veneer lumber for increased rigidity and stability. The doors have a pass through hinge mortise.