Looking for Foundation Contractors in Guildford GU14?

Foundations
Project Location: Guildford GU14

> Property type: House 

> Job description: Cloakroom/patio area foundation appears to be aged and crumbling. I understand it s up to 30cm in depth/ 9squ. metres worth of damaged foundation (it s only about 30cm depth /15squ. cm that s currently fully crumbled away). Interested in a) finding out if this can be done in DIY fashion using goods from warehouse and b) how much it would cost for a contractor to carry out the work if necessary. 

> Job start date: Date not set 

> The client is looking for: To have just an idea of the price