tiling outside above cafe

[Ian-james Elder]

just looking for some advise on tilling outside on a roof top. it has been tiled before but has just recently started leaking through the cafe, the reason is some of the tiles have cracked and its getting through. i was going to pull all the tiles and plywood up, and re plywood it. and cover round the edges and the joints with with waterproof jointing strips. and then use ardex wterproof coating. then tile it with a superflex adhesive and a flexi grout. would appreciate some help on this as i dont want it to leak again.

 

[Alan.P]

What size roof area is it, is it used as anything like a veranda etc, is there any give / bounce in it at the moment ? Best bet would be do as you say, pull tiles and plywood up, and see from there if it needs any preparation before re-boarding and waterproofing.

 

[Ian-james Elder]

it is used for student sitting area for the flat. there is no bounce in the floor. the roof area is about 18 square meters. i might put wedi boards down instead off plywood and use the waterproof taping around the edges to seal it.

 

[akinsontiles]

I would advise the customer to be prepared for replacing all the substrate. if there is water damage to the ply then it may have caused problems to joists as well. Pictures would be good.

 

[Rich]

Sound advice above, make it very clear to the customer that it is very hard to tell the amount of damage that has been done until you start to rip out and make it clear that your price will depend on this.

Maybe think about using a decoupling membrane to make the substrate water proof?