Hi,   I would like to share my thoughts and ask for other people opinions.   I need to make 6m by 6m flat roof with 4 skylights.   I've been a fun of engineering joists because of the light weight and how easy they are to install as well as how easy it is too put any ducting or pipes etc. However, with the timber price increases the quote that I am getting for engineering joists works out nearly double the price comparing to putting RSJ in the middle to half th