A Strut Back-Up is another option for adding extra strength to a TAB. In situations where there is no room to install a suspension system (tree branches or house in the way), the strut back up can be used instead. A Short TAB is installed below the Standard TAB and the strut back-up then bridges the gap between the two. Struts are often used when you need extra support, but don't want to penetrate the envelope of the house to do so.