This is a bungalow which we own. Since we moved here in February 1998 we have the same flat roof (did not have the insulation) and we never had any problem. In June 2014, we decided to put insulation so we called and commissioned Robinwill Group to carry the job and gave us a no quibble guarantee for 10 years. In February 2015 we started to have leaks in the kitchen.When we first reported this problem we called their office, but did not write.We sent the first email on the 27 April 2014.
We are satisfied with the answer of Joshua. Rate to finish is higher than "OK" so Joshua should get a credit.