Best method to lay strip foundations over undulating sandstone bedrock?

[overthehill]

Hi

 

We have had a call from our builder who is laying the strip foundations for our new house. The ground is all sand and sandstone and the strip foundations he is digging are hitting quite high bedrock in places then dropping three foot down to lower bedrock. There are loose sandstone peices which means the pit walls are falling in places and other places the bedrock is sticking into the trench.

 

The builder has proposed using mesh and filling the trenches with concrete but this means using a lot more concrete than we have budget for.

 

Has anyone encountered this before and if so did you find a cost effective solution? 

 

Any ideas apprecaited!

 

 

 

 

[Nickfromwales]

To be honest, you may be better off with a raft foundation depending on what the average depth is. 
 

You also REALLY need to be asking a paid professional such as your structural engineer, as neither you, your builder, nor the 21,200 members on here can tell you definitively what to do to resolve this  

[Russell griffiths]

You can buy some expensive shuttering to form the sides of the foundation 

buy the time you have bought it and payed to fit it you might as well just rip a big wide trench in and fill it with concrete. 
 

it’s either 2 grand in shuttering or 2 grand in more concrete. 
 

Or stop work and re design everything. 

[overthehill]

thanks guys, yes agree a decision for a professional but good to get combined experience here too. With hindsight a raft would have been better. Stopping work isnt an option as the kit is on its way so we need to keep going, more money and more concrete has been decided as the way forward 😒