I have a log cabin that has a ceiling made of 200 yr old barn wood. We are wanting to stain it solid but there are large voids between the planks that are allowing the blown in insulation to fall through the cracks. some of the gaps are 3/8 inch most are less than a 1/4. please help me with any solution to fill these voids
And all the heat or cooling is also leaking into the attic.
There is nothing that would look right to fill the gaps with.
You could remove the insulation, add a vaper barrier in the attic, air seal it then reinstall the insulation. Or go over the whole ceiling with new T & G material to seal it up.