Mastic replacement windows

[bjr2014]

Just had Mastic double-hung windows installed. When the outside temp is about 10 degrees cooler than inside house temp, the top portion of the windows fog up on the outside. And the fogging is 3-4 inches from the outside edges of the window. This is just summer. Can't wait to see what happens in the winter (not) Could there be a problem with the glass seals in the window? The casing is vinyl and the installer did insulate around the window frames. Have checked the Mastic website but found no answers.

[HomeSealed]

Is it high humidity outside? AC running inside? .... Not an uncommon occurrence to experience exterior condensation in the summer time. Dependent entirely on conditions, not likely a product defect. If the fogging was between the panes, that would be a different story.

[randy]

HomeSealed is correct, very common when it's humid outdoors and cool indoors with the air conditioner running. Typically occurs in the morning and is gone by 10am or so. Here in Houston it is the norm during the summer months, particularly when there's a flowerbed beneath the window that is being watered on a regular basis.

The outside surface of the glass is reaching the dew point and therefore you're getting some condensation there. No problem at all.

[Windows on Washington]

Exterior condensation in these cases is a good thing.

Means your windows are working.

[bjr2014]

Thanks for all your input. This never happened with my old single pane windows. Just hope the new windows don't freeze up in the winter.

[Windows on Washington]

There won't be enough moisture in the air when it is cold.

I promise you they won't get exterior pane ice.