My house was built in 1951, and the door leading to the garage from the basement is cut through the concrete blocks. The original carpenter attached jambs to the ends of the block walls, then hung a door between them. It's time to replace the door, and I'm a little unsure of the proper way to approach replacing with a pre-hung door.
The old door is still in place, but as best I can tell, the opening in the block walls is 39 1/4 inches. The typical 36 inch door needs a 38 inch opening, leaving 1 1/4 inches for rough framing. This would leave room for 5/8 framing on either side, though this sounds too thin to me. But to skip the rough frame would require nailing through 5/8 of shim on each side, which sounds wrong as well.
Am I missing something? Or is it not correct to replace this door with pre-hung?
Thanks.
The old door is still in place, but as best I can tell, the opening in the block walls is 39 1/4 inches. The typical 36 inch door needs a 38 inch opening, leaving 1 1/4 inches for rough framing. This would leave room for 5/8 framing on either side, though this sounds too thin to me. But to skip the rough frame would require nailing through 5/8 of shim on each side, which sounds wrong as well.
Am I missing something? Or is it not correct to replace this door with pre-hung?
Thanks.