# window jamb extensions too short. ideas?



## itsnotrequired (Apr 30, 2010)

opening up the basement wall to install a larger window as part of a basement finishing project. from exterior concrete face to interior face of final drywall will be 14" (8" thick concrete + 2" XPS foam + 2x4 stud + 1/2 drywall). new vinyl window jamb depth is 3 5/16" so i ordered it with 10 11/16" jamb extensions, factory applied. this would give me the 14" from the nailing fin to the end of the jamb.

well, somewhere along the line the supplier and i got our wires crossed on the terms 'jamb extension' vs 'jamb depth' and the window ended up with an overall jamb depth of 10 11/16", not 10 11/16" jamb extensions. result? my jambs are now 3 5/16" short.

ideas for finishing this off? window is not yet installed so here are the options as i see it:


return the window. not really realistic since no one is really at fault. it would delay my project, i would likely incur additional costs, etc.
install the window 'recessed' from the exterior concrete face by 3 5/16", such that the jambs would now be flush with the drywall. not desirable since it will reduce light, create a 'cave effect' and introduce potential water intrusion (concrete lip at the sill)
scrap the existing jambs and put new ones in. i'd rather not do that since they match the other windows in the house (laminate finish) and i paid $175 or so for the jambs to be included and installed at the factory.
'extend' the jambs. jambs are 5/8" thick so i was thinking of getting some 3/8" stock, painting it white to match and bringing it out flush with the drywall. there would be a lip where the stock meets the extensions but it shouldn't look too bad.
option 4 seems like they way i will be heading but wanted to see if folks had some other ideas.


----------



## joecaption (Nov 30, 2011)

Hard to say without being there to see it, but I make them all the time out of 3/4 clear pine or Birch, just prime and paint before installing.
If you use enamel semi gloss paint it should match close to the laminite.


----------



## Jackofall1 (Dec 5, 2010)

Why not use the same thickness material, I would use either bisquits or dowels to strengthen the connection between the window and the extensions.

Mark


----------



## itsnotrequired (Apr 30, 2010)

Jackofall1 said:


> Why not use the same thickness material, I would use either bisquits or dowels to strengthen the connection between the window and the extensions.
> 
> Mark


i've seen that for wood windows but this is laminate with a plastic-like exterior coating. think laminate shelving. plus, there is a rounded finish on the end of the extensions. my fear with same thickness material is that there will be this gap that i can never get right. purposely introducing a small step will at least make it look like it wasn't a total screw up.:laughing:

also thinking of making the extension a different color, sort of like an accent piece. or possibly out of stained wood to give a richer look.


----------



## joecaption (Nov 30, 2011)

That's why I suggest the enamel paint, I just had to add extentions to a laminite vanity because the new top was to big to fit.
Unless you knew where to look no one would ever see it.
I used Kreg screws from the back side and there's 0 seam gap.
With door and windows jamb extentions it's common to have a step, so it's no big deal. Just make it equal all the way around.


----------



## itsnotrequired (Apr 30, 2010)

joecaption said:


> That's why I suggest the enamel paint, I just had to add extentions to a laminite vanity because the new top was to big to fit.
> Unless you knew where to look no one would ever see it.
> I used Kreg screws from the back side and there's 0 seam gap.
> With door and windows jamb extentions it's common to have a step, so it's no big deal. Just make it equal all the way around.


yeah, this rounded edge and lack of being able to get at it from underneath makes me want to shy away from trying to make it even. and like you say, it isn't uncommon to have a step. might actually look good rather than some 10.5" extension. it would basically be a shelf!

and yes, make it equal all the way around.


----------

