Tony Welch and his mum Elaine visit Topsy and Tim with Tony's new baby brother Jack. While the baby sleeps, the children help DIY Derek measure Topsy and Tim's bunk bed. The bunk is being given to Tony when the twins move house and Elaine wants to be sure it will fit in Tony's bedroom. As the children measure the bunk, the tape measure becomes difficult to use, but DIY Derek has an idea for a way to measure the bunk bed which is much more fun. Show less