Existing large flat roof, want to deck it, approach?

[jmedwards]

Hi all

I have a large flat roof (about 50 sq meters) which I want to turn into this:

But right now, it looks like this:

Another leasholder owns the flat below our flat roof, which is rented out. The flat roof is demised to me for use as a 'roof terrace' and it is my responsibility to maintain it. Right now, it isn't fit for purpose as a roof terrace and questionably as a roof.

I know the following about the condition of the roof:

- It was recently covered (what you see) two years ago.
- Under this cover there is at least two layers of asphalt and one other layer of this covering.
- It isn't draining properly and has substantial ponding in two places.
- It has two skylights (pictured).

I need to make sure the roof is as impecable at being a flat roof as I can make it, so issues aren't caused by below. Then, I want to surface the roof for a deck.

I am curious as to what your own approaches and considerations to doing this would be:

- Re-roof completely, then deck?
- Not worry too much about the existing roof and build a floating deck on top?
- ...?

Thanks in advance for your thoughts...

 

[Xenon]

If the felt is in good condition (Looks like its had some bodgy patches?) You can rest bearers on a loose felt pad and build your deck off that. Make it sectional and outlet panels built in for cleaning.

The height of the parapet will needs to be 1070 mm to meet regs, you may have to have a rail fixed to the top of the coping. Would recommend pointing coping joints as well. Rooflights are late type so they will be mansafe. Use an elastomeric coating for wall Deckguard W or similiar.

 

[catlad]

Have a look at a web site called wallbarn they do adjustable supports for roof decks.