Are these stops designed to seal positively without silicone or should they have been siliconed by the manufacturer?
If they are not sealed totally the efficiency of the window is lowered because of the faulty seal. How common is this problem with vinyl windows?
Most vinyl windows are of very poor quality, which is why they are cheaper.
As with most things, you get what you pay for.
The stops are not intended to be sealed.
All of the sealing happens with the external caulking, a good thermal pane, and a good foaming job.
If you are concerned about efficiency, R value and quality, you may wish to consider better windows.
Yes. In most cases, they have a small rubber seal on the inside stop, and snap in place. The outside is sealed with rubber or butal tape, or both, no silicone for vinyl.
Vinyl (cheaper grades) are cold for the most part, because of moving air in the frame it self.
Hope this helps.
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