Tiling a Rooftop Patio

I would put a screed on the floor then water proof all the joints and corners with tape and brush on a waterproof product of your choice. I recommend using Bal products. In regards to the tiles make sure they are fit for exterior use. A reputable tile supplier will guide you with this.

Difficult to answer this one and never come across this before...Firstly i would find out from a structural engineer if your roof would be capable of supporting the extra weight you would be loading onto it by adding tiles. Then if that is ok telephone one of the adhesive manufacturers tech helpline and ask them which adhesive would be best. Personally i would not recommend tiling onto felt at all.

The screed would need to be 50 mm thick at least or it will break up,plus the extra weight needs to be checked and make sure there is no movement

I would make sure it’s screwed solid in 12 ml ply, then I would use a tanking wetroom system mapei is a good choice with a membrane, then flexi adhisive then grout This would make a very good structural floor and would last years and no leaks

Hi there, I wouldn't put tiles straight onto the felt roof. I would use a decoupling membrane first. Lay it with a small bed of adhesive. 3mm ideally then let it set. Once thats done you're good to go with the tiles. Plenty decoupling membranes to pick from. I have used Durabase CI a few times. Decent stuff to work with. Also make sure the adhesive and grout you use is suitable for outdoors and bear in mind the temperature when doing the job as it needs to be a minimum of 5 degrees with most products. If working in cold temperatures like this it will affect the times it takes for adhesive and grout to set. Food for thought. Hope this helps.