Timber decking above asphalt flat roof

[bb48]

I am considering timber decking in an area roughly 30m2 to convert a flat roof into a balcony.

On two sides there are solid brick walls. On the other two sides there is concrete base to the fences. The decking could be bolted onto all four sides to spread the load.

Is it possible to build the decking with minimal or no contact with asphalt underneath?

If it is safe to build the decking, I am thinking of going to Wickes for it. Finally, is the project do-able by a novice?

 

[fathead]

assuming the area is 6m x 5m?? i would say the span is probably a bit wide without any support in the centre. withot knowing actual sizes it is hard to say. as for buying it from wickes i would maybe try some timber yards first, most now do the decking and you can normally get a better price. that wasnt much help was it!!!

 

[bb48]

assuming the area is 6m x 5m?? i would say the span is probably a bit wide without any support in the centre. withot knowing actual sizes it is hard to say. as for buying it from wickes i would maybe try some timber yards first, most now do the decking and you can normally get a better price. that wasnt much help was it!!!

Yes, the area is 6m x 5m. How far apart should the support be? Would it be OK to use marine ply on the asphalt to spread the load of the supports? Are there recommended sizes for the bolts?

Thank you for nudging me towards my friendly local timber yard - I do not know why I did not think of them first. Possibly, it is the effect of advertising that I can't see beyond Wickes & Screwfix to solve all my diy needs.

 

[fathead]

posting at 5.13am? cant you sleep!!!! spacing of the supports woul depend upon size of joists etc, it is hard to say without seeing the job, i personally have never decked over a flat roof before,but i would think it may be an idea to try and fit a steel rsj through the centre of the deck to support the joists fitted from wall to wall. this should stop you having to support the deck from the roof. hope this makes sense and good luck with the job...

 

[bb48]

Before posting my request for advice, I was most concerned about how I describe what I need to know (would I be able to explain what I need to know, have I forgotten something important, would I end up sounding like Donald Rumsfeld "... the known unknowns and the unknown knowns..." and I forgot that my postings receive time stamp!

Thank you fathead. I hope I find out how best to convert the flat roof space into a nice balcony in the next few weeks.

 

[oweno]

I would investigate the timber sizes [and spacing] of the supporting structure - if you are really lucky then the timbers for your flat roof might be big enough to support floor loading (see the old building regs which include the timber sizes)

- if not then consider ripping up the current roof deck and doubling up the timbers - relaying a new deck (with insulation complying to current standards)

- then use a mastic asphalt product over the roof instead of timber decking.
http://www.masticasphaltcouncil.co.uk/
http://www.ruberoid.co.uk/index.php?page=95
http://www.pureasphalt.co.uk/products.htm

Owen

 

[thomglasgow]

hi there do decking for a living ,do not go to the big stores,go to a timber mill where you will find timber most costs effective ,flat roofs are not a problem as long as the load is spread evenly,make sure roof is well sealed prior to decking project all the best.