DIY Home Improvement Forum banner

Window Jamb Extension

2061 Views 3 Replies 3 Participants Last post by  xlr8tn
I need help with a basement window jamb extension. The wall in front of the window appears to not be square with the window and depths range from 14 3/4 to 15 1/4. Since the depth is greater than 12", I purchased laminated pine planks that were 18" wide.

Here is my plan: Since the box needs to be square, I was planning to build it based on the largest depth at 15 1/4 and add for a 1/4 reveal all around. I was going to install and shim temporarily and then use a pencil to mark a flush line all the way around. Then, I plan to make the unit flush with the drywall by using a hand planer.

Now, is this what you would do or is there another way that I am not aware of? Should I just plane the jamb when it is attached or remove and work on it? Any help would be appreciated.

1 - 1 of 4 Posts
This sounds like it could work, but it might be more effort than you need. You could also just put each individual component up at a time and scribe them instead of building the box first, then you might have an easier time cutting the board down to fit without having to worry about clamping the entire box down and maneuvering it while planing each piece with it all still connected together. The corners might start to loosen apart unless you're planning on separating the box again after you take it out? But that would mean you'd have to but it all back together a second time and spend extra time worrying about damaging the box in the process.

Also you could freehand the scribed pieces through a table saw for a faster cut than hand planing them, or use a belt sander to quickly take the wood down and then lightly plane it after to smooth it out and make the process easier on yourself.
See less See more
1 - 1 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.