Insullation in old home. Worth it?
We have a 1900 two-story + attic fixer-upper, and just got a new gas heater installed. Of course, the heating company told us that since the home is not insulated, we should look into it, and he suggested a place that can give us an estimate on spray-foam.
Bad thing #1) We're doing research on it, and it seems like we're looking at about $10,000. How long is it going to take before we make our money back? Fifty years? Just spent $14K upgrading from an old oil guzzler to a new HE gas heater. If we save $50/month on the heating bill, it will take about 16 years just to pay for the insulation.
Bad thing #2) We're reading a lot of bad things about harmful effects of spray foam insulation. Not to mention reports of "fishy smells" that may come from it in the heat. My wife absolutely hates the smell of fish.
Bad thing #3) We're not only hearing that an old house cannot "breathe" with insulation, but unless you have a vapor barrier in the wall (impossible with plaster & lathe), moisture from cooking, showers, dishwashers, etc, can get into the walls, causing condensation on the insulation, which attracts termites.
Bad thing #4) We're reading that when the spray foam expands in the walls, it can (and usually will) cause the wood lathe to expand, pop nails loose, and therefore cause the plaster to crack all over.
Question: Would installing fiberglass insulation myself in the attic do any good? We have no heat or air conditioning in the attic, so I don't know if it would do any good.
Question: We are leaning towards vinyl siding anyway. This, I'm sure will help, but will it be good enough?
Thanks in advance.