Mark Fenemer

Hello, I would like some info/advice regarding a cold concrete flat roof. Sorry for the length of explanation.... But first a little background info...... The house we purchased was gutted, renovated and then sold on to us by a local building company... All certs for all upgrades and works were checked and passed.... Our problem.... 1 We moved in Sept 2107 all is fine until the first frost off this winter late 2018..when we started to notice a water stain in the rear utility ceiling (formerly downstairs rear loo and storeroom). These rooms were incorporated in to the house via the kitchen to form a utlity/cloakroom and extra kitchen space..... The roof itself is around 8 inches of concrete topped off with felt.. This was refelted just before we moved in... And the rooms below batterned, insulated, boarded, skimmed and redecorated. Oh and rads fitted. Since this watermark has appeared and got worse over the last month or two.. I cut a peice of board out, to be greated with a soaking wet inner roof, droplets everywhere.... Our problem 2.... The house is a semi formerly a council house, we have great neighbours who are council tennents... They have the same sort of rooms as us but still the original loo and store (no heat sourse).. And attached to ours So taking advise online of fitting a VCL then a thick insulation then watertight layer is not really an option without affecting the council properties roof.. So I am left with trying to sort the problem from inside.. Although there is much advice regarding how this is now not advisable.and insulating from outside is they way to go... Is there anyway I can fix this from within... I am happy to take down the internal ceiling and start again. But what would be the recommended materials etc etc.. To ensure no water ingress... You can see by the images that there is no VCL inside and the insulation is very thin and not sealed in anyway. Just placed in the roof void not a good job at all.. ... Please please any advice would be gratefully received.... Mark