Grout is a block added by Tinkers' Construct that is primarily used in the creation of the Smeltery after being turned into Seared Brick then into Seared Bricks. If you assume that a "basic" Smeltery with one basin and one casting table and no glass windows, you'll require 164 bricks, which means you'll need 82 each of Clay, Gravel and Sand. This will create 164 Grout which will become 164 Seared Brick. If you substitute Seared Glass in any of your Smeltery walls, you'll need an additional 1 each of Clay, Gravel and Sand.
Makes 8 Grout.