IT DEPENDS ON THE COMPATIBILITY OF THE NEW AND OLD BRICKS.
FROM YOUR DESCRIPTION, I ASSUME THAT THE NEW BRICKS ARE ENGINEERING TYPE. (FROST AND WATERPROOF).
THIS TYPE OF BRICK IS EXTREMELY HARD AND BRITTLE AND NOT ABLE TO WITHSTAND THE STRUCTURAL MOVEMENTS THAT A SOFTER BRICK CAN WHEN COUPLED TOGETHER AND WITH THE DIFFERENT MORTAR RATIOS REQUIRED CAN MAKE FOR FAILURE AT JOINTS.
IF THEY ARN'T COMPATIBLE WITH EXISTING BRICKS THEN THEY MOST LIKELY SHOULD NOT BE BRICK BONDED BUT COULD BE TIED IN USING A FURFIX PROFILE FLANGE AND CLIP SYSTEM WHICH WILL ALLOW FOR STRUCTURAL MOVEMENT BUT STILL TIE STRUCTURES TOGETHER.
Last year 64% of the questions asked in our forum were answered within our DIY project pages at www.diydoctor.org.uk/projects.htm The project pages are now separated alphabetically and your answers are accompanied by diagrams and the ability to see, and buy, the tools and/or required to complete your project. Use our search box to look for your answer and save a great deal of time and money!
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!