Hi i am going to make the opening from the main house outer cavity wall wider.The opening is 850mm and has a wooden original lintel holding it at the moment. I am making the new opening 1200mm wide. I will be fitting the new lintel underneath the existing lintel,at one side it will be sitting on a cavity wall and the other on breeze block.what size lintel should i use and can it be concrete or wood.
would be grateful for any help cheers alfiem
would be grateful for any help cheers alfiem