Guess i'm just nervous about cutting a hole in the wall, etc. I built the interior framing and have the window. Here's my plan: Drill holes in the corners of the frame area to the outside to use as a guide to cut the siding. Go outside and scribe/cut between the holes to get the window area to size. Remove some nails from the siding near the window so I can slide the window frame in underneath the siding. Install window weather tacking inside/outside frame. Remove the screen and sashes from the new window and fit frame under siding. Level the base and fit spacers in loosely. Tack frame in place and install the sashes. Do final squaring up, nail fins in place, then check again. Fit vinyl into exterior channel. Finish insulating inside. Q: Will cutting the vinyl to frame size allow me to slide the vinyl into the window vinyl groove? does it need to be a different size? If there is foam under the siding, does the window go over that? Any other suggestions or anything wrong with my plan?

I am converting a deck to an enclosed sun room. The original railing had glass panels. I sized the deck panel width myself so I could place standard commercial door glass as panels. Basically, a frame of 2 by 6, with a small strip on front and back holding the glass in. Worked great. However, I am now trying to use the same glass panels as lower windows in the sun room. I removed the glass and used a pvc trim to form the exterior support the glass would rest against. Caulked the inside with silicone and placed the glass. I then applied pvc trim on inside to secure glass, and trimmed the window. Looked great, but leaks like crazy when rain and wind hits it. I did the same thing with a vinyl clad "replacement window" from Lowes for the upper windows; I placed a replacement window into the framed hole, screwed it at sides, caulked, and am leaking.... What did I do wrong. Should I have used a glazing compound instead. How would a professional approach this project. I know that an ideal solution is a window for new construction with fins... Can I fix this with same windows. I am happy to remove them, but cant afford to toss these windows out and use 'new construction' windows... How can one waterproof a window like this that is set into a wood frame (hole in the wall)...