I have just had a fireplace opened up and enlarged, to take a basket for a coal fire. The builder has used a piece of treated timber as the lintel and I am concerned it will get too hot and catch fire. He tells me this won't happen but I am still worried. Can anyone advise?
It is difficult to give an opinion without seeing the installation but the BRs require that any combustible material is placed more than 200mm from the inside surface of the flue.
Assuming the builder was hetas registered you can either accept what he says or contact hetas for help.