Sometimes it amazes me the shortcuts some people take… One of the biggest things that has come out over the years is when installing a product make sure you read & follow the manufacturers directions. Bah, this way is faster & we have never had a call back…
This is from a window with a nailing flange which you can see they completely ignored. No big deal it was for a masonry opening & they used clips, right? Nope
Granted the manufacturer does allow for this type of method, but you shouldn’t be driving nails in at an angle much less through the trim. Oh & in case you missed it on the picture above the extension frame should not be already attached, if done using this method it is to be attached as a stop so the window doesn’t get blown into the house. Remember nails only resist shear.
But wait it gets better – the shims used should not extend from front to back, but rather be a half to an inch back on both sides… Oh & where is the caulking on the inside? (Not only to stop air-leakage, but as required per the manufacturer for this type)
One last item, just caulk to help keep everything watertight & free of air-leakage… Yeah I don’t think so – you should see some flashing tape residue on the window as that is used to accomplish those tasks (per this manufacturer). Having seen many “window” failures over the years, it is a good thing this one was pulled as the damage that could have happened goes beyond just a slightly drafty window.
Want to avoid these problems, order the proper window for the opening (they do make special windows for those that don’t like using nail fins) & make sure the steps the installer is going to use, are what the manufacturer recommends.