The ceiling of the first floor is composed of old tongue and groove boards which, with the passage of time, have very slight spaces between many of them.
Above the first floor ceiling is fiberglass insulation AND (and here’s the problem) dust composed of decades-old chicken crap and random barn residue that was never properly cleaned out when the barn was converted to a house.
Above the insulation and dust is the second story floor, which is quite nicely done.
So the problem is that small amounts of this dust are constantly falling between the cracks of the ceiling. Not usually enough to see it fall, but enough to be constantly putting a layer of dust on everything in the first floor. And if you bang on the ceiling with a broomstick or jump up and down on the second floor, then you DO see it fall.
The only way to get in there to clean up the dust properly would be to pull off the ceiling of the first floor or the floor off of the second – neither of which I am particularly keen on doing.
The cracks between the boards are about 1/8 of an inch.
Question #1: Is there any type of clear varnish type substance that I could effectively seal up the cracks with?
Question #2: Any other solutions you can think of to this problem?
That was a complete screw up by the person that made it into a house. The tongue and groove boards should have had a liner to prevent your problem. I can’t think of a thing to do about the problem that is simple. Using a sealer on the ceiling won’t do any good as the wood will expand and contract. The bottom of the home sounds pretty useless because of the filth dropping down. You will probably have to install a liner and new ceiling under what is there.
What kind of liner are you talking about and where can one find them? Are they typically used specifically for situations like this or are they commonly used for other purposes too? I would have thought that proper cleaning in the beginning would take care of it in most cases.
After actually reading the question, my first thought would be drywall screwed into the underside of the first floor ceiling. I’d want to look into whether expansion could cause cracking after it was finished.
If you like the wood look, it might be easier to put in the drywall, or some other barrier, then add new old wood below that.
The walls are all wood, so I think I would go with wood for putting a second ceiling in. Besides drywall, what might be some other types of barrier options?
you can get 4x8 wood sheet material that is tongue and grooved and apply to ceiling. it can be with grooves or other finishing to appear as narrow boards.
go to whatever home improvement store or lumber supply places local to you and see their selection. it is a usual item for those places. it is a plywood product with a good face. grooved material looks like boxcar siding.