Garden Office/Workshop Foundations

[bodge_it]

Hi all,

I'm planning to build a 6x4m timber framed outbuilding in my garden. It will have a twin pitch, tiled roof (eaves at 2.5m, max height 3.6m). There is not really much scope to amend this design as I already have all the materials!

I need to check the subsoil consistency but about a foot below ground level is solid chalk. I was planning to lay a reinforced concrete slab but it's about 25m to the nearest road and so I imagine I'll have to pump the concrete in as I don't fancy 100+ wheelbarrow trips! If there is an viable alternative to a slab that means less concrete then I'm all ears!

If I do opt for a slab I'm also unsure of what thickness I'll need. Is 6" likely to be enough? Am I likely to be able to use something thinner than this if the subsoil is solid enough?

I realise I could employ a civil engineer to undertake a survey and calcs but this seems OTT for something that is essentially a very large shed. I'm sure an experienced groundworker or builder would be able to give a fairly accurate indication of what I need but I figured a quick post on here might flag up some other ideas/suggestions.

If it helps I'm located in Croydon, South London so open to recommendations of local firms who may be able to assist in some way.

Cheers

Rob

 

[nickjb]

You will need building regs sign off for a wooden outbuilding that size so it may be dictated by what the inspector wants.

 

[bodge_it]

Nick, 6 x 4m is 24m2 therefore exempt from Part A-K, M, N and Q on the basis of being categorised as 'small building' under class 6 of the building regs (i.e. less than 30m2). It can be made from timber as it will be located more than 1m from the boundary of its curtilage. It is also exempt from Part L on the basis of it having a floor area of less than 50m2. The only regs that I can see apply are Part P but as I intend to have the electrics installed and signed off by an electrician I believe I'm all good there too.

 

[r896neo]

125mm will be fine. I would put in some mesh at that size too. Pumping will be terror expensive. A gang of 4 people could barrow that amount in 30 mins probably.