Historic wood windows are special compared to your average modern window in that they can be repaired. A sash contains four main pieces of a frame. 2 vertical pieces called the “Stile” and two horizontal pieces called the “Rails”. The stiles contain a female component called a mortise and the rails contain the male component called a Tenon. They are pinned together and not glued so they pins can be removed and the sash can be disassembled. We’ll run though this process in a series of photos to depict how wood repairs are made on wood windows.
Interior Side of the broken mortise.
A screw driven into the wood helped speed degradation.
Exterior Side of broken Mortise.
This mortise split along the wood grain. This is a rare anomaly.
Both sash have stiles removed and ready for the repair.
The new stile being installed.
Here’s a view of the mortise and tenon fully mated.
A stainless steel 1/4″ crown staple is used to fasten the joint. Depicted is the steel nail that was removed next to the stainless steel staple.