I gave an old home and the fireplace on the outside shows cracks and shifted brick. I tried to use the fireplace and it was fine but eventually smokes started coming in the house. I know there are cracks but I'm looking for an inexpensive way to seal cracks on the inside so I can use the fireplace as I can't afford to fix it properly. Yes, the vent is open - I checked. I'm worried about using a spray sealant and actually really messing up my fireplace. Any suggestions?
Cracks shouldnt create backdraft. The vent may be open but my flues always seem to get clogged. Birds/squirrels love to make nests in them.
Best bet is hire a sweeper. Or at least go up on the roof and check its clear.