On 17/03/2015 startedwithtrees wrote:
>Thanks Guys. You're all correct - topsoil is very heavy, especially when
>saturated!
>
>Apparently green roofs tend to use lightweight growing mediums e.g. vermiculite
>mixes, which bring down the weight . A landscape architect is advising
>on growing mediums, plants and resulting weight m/2 for a shallow green
>roof, as well as the layers required e.g. waterproofing, root protection
>barriers, drainage layers etc. Her brief phone advice was that for 30
>mm depth additional weight would be around 100kg/m mark (TBC).
>
>However, we'll need a structural engineer to calculate the weights based
>on the LA's advice, and work out what additional reinforcement the garage
>would need. We haven't built it yet, so hoping its easier to build strong
>enough rather than retrofitting. A bit unusual, so guess it would be best
>to hire an engineer with at least an interest in the area, if no direct
>experience. Was hoping some of the engineers on chokky might fit the bill
>or know someone... given we tend to enjoy the outdoors more than some!
First thing needed is the size of the garage ie length by width , the load to be carried is proportional to the span squared that is 4 m width gives say a load of 16 where as 6 m give a load of 36 is more than double |