Was the ridge vent reinstalled?

shingles went all the way up to the peak. there were some whirlybirds that were out in though.

"installing a new roof or siding reduces air infiltration into your home, making a tighter seal. This tighter seal is great news for your energy costs, but a tightly sealed home also retains more humidity"

You say inside of windows. You don't say east west north south exposure. Are all the rooms affected on the same side of the house?

Given you said "winter" and not all year long........it's cooler outside air, a much tighter seal of the house, and the warmer , more humid air inside. Showers, warmth of dishwasher, even humans breathing.

I'd first try opened windows on a few sides of the house, and check your humidity level too.

Also use exhaust fans when creating humidity inside: showering and cooking.

I don't quite understand, were the whirlybirds kept, or removed? If they were removed and nothing was installed to replace them, that would explain the excess humidity in the house.

A roof needs ventilation that comes in through the soffits and exits at the top either through a ridge vent, a whirlybird or, very popular in my province of Quebec, Canada, what is called a Maximum ventilator, essentially a fixed whirlybird.

Hello and thank younfor your reply. The whirly birds were kept

@Windows on Washington Ltd its a one story home with gable vents on two sides of the house. when it was re-roofed there was a ridge vent at the peak that i dont think was replaced but there was one whirly bird that was out up. the majority of the home is tongue and groove ceilings there is very little attic space

If the ridge vent is covered? There's your answer........

Needs considerably more than one "whirlybird" typically. As well as soffit vents.

If they closed the ridge, likely that the reduced the NFA to a point where it's not moving enough air. Need to know the footprint to do the calculations, but this needs to be a conversation with your roofer.

Start with the ridge vent and soffit vent situation. The two have to work together, along with the adequate air sealing and adequate insulation. You want the attic to have enough air flow to be at ambient temperature. But it sounds like you might have living space in your attic? If so, then it sounds like the whole air sealing/insulation/ventilation of that may be incorrect.

+1 to the advice to discuss this with your roofer. If all he does is come out and say everything is fine, you'll probably need to get a third party involved.

Its very possible that (as others have already allluded to), the ventillation of your attic was reduced and is contributing to this. If that is the case, there's probably even more condensation in the attic than what you see on the windows, and that is a much larger concern.

Did you have any insulation or air sealing in the attic done with the roof replacement? In that scenario, this would actually be expected as it would reduce air/moisture leakage from the living space through the attic.