I just purchased a new house and have been replacing the rotten wood that was on the frame of my front door.
Basically the threshold (when built) had a slight bow in it and leaned in to the house from front to back, therefore when it rained the water collected in puddles around the base of the frame uprights. Over time this has rotted away the wood.
I tested the external faces and cut out 8" all the way back in to the cavity. I fixed new filler pieces to the masonry and built the frame out profiling the grooves, etc. I spent quite a bit of time getting it to match!
Everything looked to be in order. At this point I started to chip away some of the concrete fascia next to the frame as this had been affected by damp too. In chiseling some away a large lump of mortar and brick fell away exposing the cavity and showing me a bigger problem in the sense that the external fascia of the frame is fine but the internal cavity side of the frame is dry but totally rotten.
I repaired about 8" of the frame, but from the hole that was exposed i can see up about 12" inside the cavity.
So, my question is. What do I do? Replace the entire frame or use a wood preservative/hardener and inject that at regular intervals into the frame all the way up?
Thanks for your time and sorry for the long post!