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Community and Q&A

Storm windows properly installed?

1910duplex | Posted in Energy Efficiency and Durability on

We purchased eight top-quality Larson storm windows with Low-E glass to replace old aluminum storm windows (or in one case, put a storm window where there had been nothing). (These used to be called ‘gold’ tier.) Many of our 100+ year old windows were tightened in the process of either replacing ropes or replacing broken panes, but not all. All got new glazing.

On some windows, the storm window does not sit flush against the vertical edge of the casing. Is this a problem? (our house is not tight at all, there is no insulation in the walls, and obviously the cavity where the weights sit is also a source of air movement) 

There are vertical cuts in the bottom segment of the storm window, as seen in the picture below. Are these the weep holes? The storm windows did not include screws for this spot, so they should be left alone, right?

Final question — one bedroom window, but not the other two, gets condensation on the inside of the storm window sometimes. (second floor bedroom). No other storm window in the house has this issue. Should we just watch to make sure the sill between the two windows is not getting big drops of water on it/is not damp (it is freshly painted)? Or is this serious enough that we need to either re-install that storm or take the bottom sash out and tighten up the window more? Or even have both sashes removed? (That costs $600)

For what it’s worth, we’re in zone 4a, storms will be closed about five months a year, and we have a hot water cast iron radiator below two windows in bedroom, the one getting condensation and the one that’s not.

Image result for larson gold storm windows sill

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  1. Expert Member
    Akos | | #1

    Condensation on storm windows is typically from interior air leaks. If it is light and you are not getting liquid water on the bottom, then I wouldnt worry about it.

    To fix it, you either have to tighten up your casemets (rope caulk can do magic on this front) or loosen up the storms to get more exterior airflow and drying. This is not ideal but better then peeling paint down the road.

    The slots on the bottom are weeps, they should not be plugged up. The rest of the storm should sit tight against the window for best efficiency. You don't want this super tight as you always need a small amount of air flow for drying but not big gaps.

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