Earthen pot and clay lamps are not taxable under GST. Building bricks, Bricks of fossil meals or similar siliceous earth and earthen or roofing tiles attract 5% GST rate.
I highly recommend George Mack of Woodinville Chimney Sweeps. He has cleaned my chimney, etc. His website states he does tuck-pointing, which is what it sounds like you need. He has a website where ...