Flat roof / balcony.

[JCB520]

Ok. the extension shell is nearly done, roof is on and nearly finished (facias and guttering to do), now comes the flat roof / balcony.

For those who need a background, I have built a 2 story extension which the back 2meters is only single story and the idea is to turn the flat roof into a balcony coming from the new bedroom.

I am struggling to get my head around the design of this.
So far I have come up with putting down 20mm marine grade ply and then some form of damp proofing (3 layers of dpm / bitumen / felt. unsure which is the best). My problem is what to do next.

Ideally I would like to put lightweight concrete slabs / tiles down (not decking) but these would need to be put onto a morter bed.
Does the morter bed go straight onto the damproofing or does it need to go on something else.
I read somewhere that any covering has to be raised above the damproofing so that any water that gets underneath can run along it to the eaves and gutters.

Any ideas would be greatly appreciated.

Dave

 

[^woody^]

Google for promenade tiles, and have a look at the spacers used for these

 

[freddiemercurystwin]

http://www.wallbarn.com/adjustable-height-support-pads-for-paving-slabs.htm
Out of interest, how are you attaching the handrails? I've always found fixing handrails in a situation like this a bit of a pain and it can be quite quite tricky getting it to look slick.