Flat roof over laundry/day room

[akist]

I thought I had asked this question here before but I cannot find it.

We have a laundry room attached to the house and it has a flat roof (not constructed yet).

I would like to build a door that opens into the flat roof as a means for fire escape to start with, in the future maybe a balcony.

What is the best material to make the roof with (I mean over the ceiling joists) so it can withstand very occasional walking over and in future maybe a bit more?

 

[oldbutnotdead]

Is this fire escape provision a requirement or just a bonus feature?
If you're planning possible future balcony use there are a load of implications- planning permission, dimensions of the joists, fall prevention just to name a few.
GRP is a pretty good walking surface if you double up on mat and resin.

 

[akist]

It is an extra feature I thought of adding in to allow quick exit from upstairs.

My engineer said the door will have to be special fire door in case the laundry below catches on fire. But I do not think he specified roof construction and covering, hand rails, etc

The roof will be 4m across and 9.2m length. Engineer has specified 150 x 75 @ 400 with 1:40 fall and I presume it is fit to take the weight of people for repairs etc.

He has also specified GRP, but again without accounting for people walking there except sparingly for repairs I suppose.

 

[oldbutnotdead]

Hmm. Engineer wants a fire rated door to prevent fire spread from the laundry into the rest of the house, nothing to do with using it as an exit route. Since he hasn't specified handrails etc. the rest of the design will be assuming occasional maintenance & not adequate for use as a balcony. Go back & get him to provide a spec for balcony use if that's what you want (but low odds you'll get pp if you ever wanted to use it)

 

[Notch7]

Engineer has specified 150 x 75 @ 400 with 1:40 fall and I presume it is fit to take the weight of people for repairs etc

It will be designed for a 1 metre depth of snow per square metre dead load I expect (about 75kg a sq metre from memory) which I would’ve thought would cope with the live load of 1 person