[Dabhand]

Hi all

Could anyone tell me please what the best footings depth would be for a 4m x 3m conservatory with dwarf wall and heavy glass roof?  Our soil is very heavy clay.

Thank you

[penance]

Not sure, but i think you might need to check building regs.

[richyrich7]

Shaun will be the man for this one Dawn    but best check with planning control, they may possibly say you don't need reg's for this but they still should be able to give you some advice.

[Dabhand]

Hi

Thanks for the replies, I have checked with building control and they say they do not regulate conservatories therefore wont commit themselves by giving advice .   I just wondered what the recommended depth was on very heavy soil.  Thanks

[poultrygeist]

When I looked into it, the rule of thumb is minimum 1metre depth plus any extra depth for certain circumstances and you need to set your width accordingly.
You may need steel reinforcing as well.

Rob

[shaun]

your right richy they dont come under building regs (council) not around here anyhow.i wouldnt like to commit myself dawn without looking at the sub soil,but i will anyway  the footing should be at least 250mm-300mm wide and 500mm  below your damp course if your house has one or floor level if it dont,then  the concrete should be around 250mm-300mm deep ,the floor slab should be 100mm-150mm ish and i would put my neck on the line to say that would do it,if you want you could put some reinforcing in the slab to be safe.if you are still not sure consult a decent builder.

[digalotty]

shaun is bang on  if you have clay ground 500 is deep enouth, and a minimum100 concrete slab but i would then screed 2inch on top or 6inch with trowel finish,reinforsing bars or mesh to slab desirable.

[Dabhand]

Hi Guys,

Thanks, that's what I wanted to hear, our builder is saying that digging the foundation to a depth of 6 - 8 inches is deep enough !!!  I had to tell them I wasn't happy and could they please dig down to at least a foot.  They have done but they are not happy with me and I think they think I am a busy body who is trying to tell them how to do their job 
I don't want to have to call them back after a dry summer and tell them the brickwork is all cracked and can they please rebuild it so I'd sooner check now.    Your advice is appreciated thanks guys......