We currently have a semi underground concrete bunker garage... it needs a new roof so we can push the soil on top of it to make a bigger lawn...
I am struggling to find any companies who would do this sort of thing..
Its not really "normal" building work... its quite specialist concrete casting etc...
Where would I look and what would I need to search for to find a specialist to give us some quotes?... I am comming up with nothing useful on google!
Really need an experienced specialist...
[Edited on 6/8/10 by tegwin]
You will need a structural engineer to come up with a specification for the structure and then the waterproofing detail, you will then be able to get a quote from a builder.
hmm, what about tiled like a swimming pool? they're pretty waterproof 
quote:
Originally posted by blakep82
hmm, what about tiled like a swimming pool? they're pretty waterproof
It's not so much the waterproofing, although that is very important, it's supporting a very heavy concrete roof, several tons of earth and a margin of error for rain and garden parties
Last night on Grand Designs there was a bungalow that was fitted with an arched concrete/insulation sandwich roof that was made in sections at a
factory and then craned in..
This one
http://www.channel4.com/4homes/on-tv/grand-designs/episode-guides/maidstone-the-hi-tech-bungalow-08-06-03_p_3.html
according to their links this place made it (can't find anything on their website about roofs).
http://www.roger-bullivant.co.uk/
Worth a call/email query.
as above, don't under estimate the weight of wet soil, its incredibly heavy and unlike other materials does not support itself with increased thickness as it behaves more like a fluid over time. I'd limit the soil thickness to just a few inches for the lawn to establish.
I'd try googling for 'green roof', seems to be a bit of a buzzword ATM.
Phil.
If the soil is too thin you will hit a dry spell and all the grass will die!
Hmm... Roger-bulivent looks quite interesting.. will give them a ring...
Ideally minimum soil depth needs to be 300mm.... So yes, quite some weight...
I guess the option is there to cast an arch.... might be stronger than a flat roof perhaps...
Hmmm will see how many thousands these people quote
If it were me i'd go for Bison style precast prestressed hollow core flooring.It's made to lenght and just needs set on.Depending on design weight you may want to beef them up with a poured reinforced concrete slab.It wouldn't be as expensive as those arch type roofs.