Welcome to Stovebolt.
Asking a technical question is as easy as when you posted this thread in the Welcome Centre forum.
Browse thru the list of forums and pick the one that's the most appropriate to your question.
You can also use the search function and find lots of information. Click on the spyglass icon near the upper right of the screen.
As to your vent window with dry rot, try browsing around in the Doors subforum of the Paint and Body fourm. That's a task I have to deal with myself, but haven't tackled it yet.
