Flat roof to slight pitch

[Bodgeitandleggit]

Guys just after any helpful info.. my 2 story extension has a flat roof and although ok when I was up there last summer was a bit tired and holds puddles so wish to do something about it, don't really want a flat roof again and it will be major work to get the house roof extended so what I propose to do is leave flat roof it as it is... then fit 3x2 battens from the existing facia board of the house under the gutter running just over the flat roof the whole length of the house say 2 feet apart ..then put 12mm plywood over this ...then use fibre cement tiles as very light and thin .. fix these then fit a gutter where the water will run.. obviously this will then take all the rain away from sitting on the flat roof but it will be a very low pitch, not sure of the degree of pitch but at a 8ft span would only drop about 5inches........ can anyone see any issues with this ? any other help/advice would be great

 

[foxhole]

Too shallow a pitch for any tiles. You could EPDM It as is. 12 mm ply is too thin.

 

[Bodgeitandleggit]

I suppose I could EPDM it...is it easy to do ? ....... what size ply would I need?

 

[foxhole]

Found it very easy, ply depends on if you are just over boarding for EPDM in which case 12mm is ok or raising the deck to improve drainage in which case minimum 18 mm. lots of online video guidance.

 

[vinn]

Why not post a photo of whats existing?

As above, you will have issues with the falls and the proposed boards.
And, given your description, you might also already have "silent" water damage issues inside the roof or behind the fascia.

The best practice is to work from a scaff, & typically remove the old roof and fascia, and then renew from the bare joist skeleton.