Hi there i have an open fire in my front room which i have opened up, at the back of the fire is exposed tondu brick, i am going to use the fire with a basket will i need to do anything with the bricks, also the fire is drawing but every now and then some smoke seeps under the lintel, is there anything i can do to keep the square opening and the fire basket as i dont want to go back to having a small open fire cheers for any help.