I have just had a lightweight roof supplied and fitted — the team of 3 were polite, reliable, thorough, clean and professional throughout. My project was complete in 2 days and the lads worked really hard, the plasters finish is excellent. So glad I chose lightweight over other quotes. THANKS LADS , GREAT JOB! There are several methods of re-roofing an existing structure, the cheapest way is to simply wrap a new roof over and under the existing roofing system. However, this method is the most likely to overstress the existing roof and wall structure. If you are offered this solution, you should ensure that the company quoting to do the work can evidence the stability of the structure with the increased loading and satisfy the building control team.