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Conservatory foundation/slab

I`m about to build a lean to conservcatory 4.2m x 2.7m on the back of my house and wanted to confirm some details. There was a 2 story extension added to the rear of the house in the 80`s so I`ve had to get planning permision which has been granted. I`ve spoken to building control and so long as its 50% translucent they aren`t needed. The conservatory will have single skin brick built side walls with insulated plasterboards on the inside face, the front elevation will have a double french door to the right and 3 windows to the left of it sitting on a dwarf wall with insulated plasterboard inside. The roof will be self supporting perspex panels.
The ground is about 150mm top soil then solid clay, I was planning on digging footings 600m deep 450mm wide, is this adequate?
What is the most suitable slab construction for this project also?

2 Answers from MyBuilder Conservatory Installers

Best Answer

If you build your walls single skin, then the plasterboard, you are going to get damp as there isn't a cavity. I suggest you get building control involved and they will guide you through what's needed


Answered 31st Oct 2012

Right then, let me explain.
A trench footing should always be over 600, to provide an adequate strata and over come frost penetration and therefore frost heave. 450mm wide is more than ample for one engineering brick to floor level
You can use Insulated ( usually polystyrene backed ) plasterboards internally if you want, but would advice cavity wall for insulation purposes more than anything.
The Slab will partly sit on top of the footings.Dont forget Insulation and dpc visqueen membrane before concreting floor

Cheers John


Answered 2nd Nov 2012

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