Flat roof garage advice

[cristianoco824]

Hi all,

I'm building a single skin brick garage. The garage is 6.1m long and 3.1m wide. I need some advice on getting the roof started. I'm planning to put the joists accross the shorter span and have the fall going towards the back of the garage. I will be using 47mm x 175mm C24 timber for joists and they will be set at 400mm centres. I would like some advice on

1. Can joists be set @600mm centres or shall i keep them @400mm centres?
2. Are 3 courses of bricks enough for the slope? garage will be higher at the front and lower at the back to allow for water run off.
3. What's the best finish for it? 15mm/18mm OSB/ Plywood+felt or corrugated metal sheets or something else. open to ideas.I won't store anything on it.don't have a budget for it but try to keep it as low as possible.
4. Where do I set the 1st joist? Flush with the face of the bricks? 50mm in? This is a head scratcher for me.
5. Overhang at front ? or sides?
6. Will it be ok to infill with bricks between joists?

Any input will be much appreciated.

Many thanks

 

[DAZB]

There are several ways of doing flat roof garages and all depends on budget, skill level, intended use etc.... I would have a look on youtube as there are loads of examples on there on how to do what you need.

 

[catlad]

Rubber roofing will be the easiest for you.
Three course of brick fall will be plenty 18mm osb t&g boards for deck, as for joist spacings measure the deck and divide equally not going over 600mm. personally I wouldn't go over 500mm

 

[Harry Bloomfield]

1. Can joists be set @600mm centres or shall i keep them @400mm centres?
2. Are 3 courses of bricks enough for the slope? garage will be higher at the front and lower at the back to allow for water run off.
3. What's the best finish for it? 15mm/18mm OSB/ Plywood+felt or corrugated metal sheets or something else. open to ideas.I won't store anything on it.don't have a budget for it but try to keep it as low as possible.

I would suggest the box section metal sheets, and at 600mm centres, but buy the heavier grade sheet, which is strong enough to not deform when you step on it, and no other support will be needed under it (no OSB). A three brick fall will be more than adequate.

I would suggest buying the insulated metal sheets, it helps avoid condensation forming on the underside.