How to install windows in 4x4 posts?

[slickracer]

We presently have a screened-in porch we would like to make weathertight. We have decided on double-hung windows. My question is....the structure is framed with 4x4 posts on 42" centers. The new windows would be approx. 42"x69". I'm thinking they just can't put replacement windows in the openings since there is no blind stop on the outside and no jamb stops on the inside. 4 screws certainly couldn't hold the window in place and I want them to be as weathertight as possible. I'm thinking they will need to add some framing to better hold the windows. Or would a better direction be to use new construction windows with a nailing fin? Any input is greatly appreciated!

[Bill62]

You need to use new windows for this application. I am awaiting delivery of windows on a job that were ordered for the exact same purpose. You may need to re-frame a little so you do not have to order custom sizes. Check with your supplier and get rough openings as close to what you have and then go from there.

Good luck!

[slickracer]

Bill, thank you. Are you capping with trim coil on the outside? How about the inside?

[Bill62]

You can trim with wood then cap the wood or you can use Azek and just paint it. Make sure you flash the windows properly, including metal flashing on top the unit, then install the wood or Azek trim.

[slickracer]

Just an update, we are having the contractor re-frame the opening with 2x6's since several of the 4x4s are not plumb and 2 need replaced since they are twisted. Should make for a better job.