I have an ash pit system on interior fireplace, chimney inspection deemed the system out of code bc the Mason never removed the plywood in the poured concrete foundation (basement height is 12 feet). The natural stone fire place hearth is 14 " above / high off the main floor living area. Inspector quoted saw cutting poured concrete to remove plywood. Is there a simpler way to seal ash dump feature in floor if fireplace vs compromising the fireplace poured concrete vault/ foundation ? Suggestions ? Time is of the essence ... any help is greatly appreciated !