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.

window joinery

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.

Ian Baldwin is a business owner in the Bellingham, Wa area. . After trying to make it as a professional road cyclist he decided to take his skills and passion of building, manufacturing, and problem solving and make a business out of it. In his spare time he spends time with family and friends and is always looking forward to his next traveling adventure.