Ideas for Finishing Around Windows

[Wilsoncb]

I am helping my daughter finish their basement. I need some ideas on how I can make the transition where the window frame is short due to the extra thick walls. It’s about 8” from where the window frame stops to the face of the 2 x 4 (where drywall will be attached). I’m not looking for a “fine woodworking” solution since I’ll be limited to a miter saw & Track saw.

I’m leaning towards just butting the drywall up to the window frame, then caulking that seem…but something tells me that caulking will eventually separate. Using some 1x10’s to butt up to the window frame doesn’t seem much better. Maybe cover the seem with a 1/4x1-1/2 trim board?

let me know your thoughts.

 

[Oka]

I had a similar issue in the lower level of my house. It is a split level (1/2 buried in the ground). Because of this, the 1st 4 ft of wall is concrete block.
So, what I did in the lower bathroom was to use a sill to cap the inside exposed top of block wall with a window sill trim, then use pre-finished Birch ply to complete the rest.
In your condition I would use the pre-finished ply on the horizontal portion to butt to the window and finish out from there to your personal preference.
I would also treat the back of the wood with Borate or Copper green to resist mold growth. You could use tar paper or equal if that is all you have.
The one real advantage of using ply is you can easily furr out the frame to correct any wall errors.
The other benefit is no taping is required - just caulking.......

 

[Henry W]

First thought - I would create a jamb extension, each with an 1/8 offset wider than the original window frame. Take that out to the face of the drywall, and then add conventional molding on the face of the drywall. DIsadvantage of this approach is that every side will need to be' shimmed' or backed with a different thickness of materail. That the look I'd prefer, not sure it would be worth the effort though. Looking more carefully at the pics, if the window is centered in the rough opening, then I think the jamb extension may all have the same offset. Bring them out to the level of the drywall, i.e finish trimming these after drywall installed.

Use plain old 3/4 poplar or whatever paintable material is available
Initial thoughts...

 

[bob vaughan]

3/4" birch plywood with iron on veneer edgebanding. The plywood will be pretty stable and flat.

 

[FredP]

I would make the sub frame 3/8" bigger than the window frame. Then use biscuits and glue offsetting the biscuits by 3/16" to create a reveal. screw some scrap to the framing to hold until the glue sets. Then caulk the reveal just like you will do with the trim. This creates a shadow line at the joint and will look like a pro did it.

 

[kserdar]

Will those window cranks work if you extend the window frame another 8"?

If Yes, then make an 8" frame extension the same size as existing box.
Shim bottom in 2-3 places, sides in atleast 1.
Use pocket holes to attach extended frame to existing. Pocket hole fillers are readily avaiable.
You can use anything that will take paint well.

 

[Henry W]

I would make the sub frame 3/8" bigger than the window frame. Then use biscuits and glue offsetting the biscuits by 3/16" to create a reveal. screw some scrap to the framing to hold until the glue sets. Then caulk the reveal just like you will do with the trim. This creates a shadow line at the joint and will look like a pro did it.

The key word here being a 'reveal' - and this is what I was trying to say too (Feel like I am in good company if this is what FredP recommends!).
How it happens - well looks like Fred has good recommendation there too.

 

[FredP]

The key word here being a 'reveal' - and this is what I was trying to say too (Feel like I am in good company if this is what FredP recommends!).
How it happens - well looks like Fred has good recommendation there too.

Guilty as charged. I didn't read the replies. Just put the fingers in motion. Too many miles of trim. A good biscuit jointer is your friend for oddball trim.

 

[MBanning]

Jamb extensions in my chicken coop, please excuse the dust. Something like this should work in your situation.

 

[Wilsoncb]

Jamb extensions in my chicken coop, please excuse the dust. Something like this should work in your situation.

Thanks for the picture, it looks very similar only now as deep. It looks like you butted flush at the bottom, but have an offset on the sides?

 

[MBanning]

I left a typical 1/4" reveal on the jamb extension, setting the casing back from the edge. The window stool extends past the casing in width and depth. The stool was installed first with the jamb and casing setting down on it.