RobinG

Yes, the stipulation for a brick finish really pushes it over the edge, although I was looking into using slips to keep the extra space requirements to a minimum. Roof wise I'm still going through it with the structural engineer as another stipulation is to include a green roof, but provisionally a warm roof with 125mm insulation finished in fiberglass, supported on a metal web joist system.

The existing building that is to be demolished is a pretty low quality, single storey, flat roofed extension to a Victorian house - so removing it doesn't really have much impact. Space-wise, I didn't really think there was that much of a difference between ICF and brick and block - because it's a single storey extension I was planning on using 6" ICF. However, a planning stipulation was to include a brickwork finish instead of render, so now I am wondering if it isn't easier to build in blockwork. It should be easier to find a builder who can undertake the whole project and relieve some of my stress at least!

Thank you for pointing me in the direction of @Stones blog - it makes a lot more sense to me now. It's not so reassuring knowing that the Nudura documentation isn't dependable - I'm using a range of contractors and the only one familiar with ICF is the chap building the walls (although it seems like he is going to have to oversee the pouring of the slab as the two jobs should be coordinated?) - so I was relying on those drawings to give everybody an idea of what they should be working towards. Do you have any recommendations of a more reliable source of info? I've attached the existing and proposed drawings from the planning application - I'm about to commision technical drawings for building control, but the engineer hasn't worked with ICF before either. The Nudura rep was very reassuring saying that they would provide all the relevant information. I want to use ICF because of the superior sound and thermal insulation properties, but also because I understood that it goes up much quicker than regular blockwork (we live in London and would prefer to move back into the untouched room of the flat as soon as possible). But to be honest, with all of the extra complication of finding people who are familiar with the methodology, I'm beginning to reconsider. Thanks again for all the help

Thanks for replying - nobody is really advising me...I'm struggling to get answers from my builder as I think he's so busy and not really in the position to help me until we're closer to actually starting work. So this is based on what I've been able to research online... I had thought that Foundations > Slab > Walls > Roof was the right way to do things, but then I saw the attached drawing and couldn't see how you could pour the slab without the wall being in place - also, it's not even shown here, but doesn't the DPM need to come from under the slab into the wall (although I guess it could be left loose and then tied into the walls once they're being built). And is it unavoidable to have 3 separate pours - the slab can't be poured at the same time as the foundations? I can see why that wouldn't be best - just hoping to minimise the budget! B6A02_1.pdf

Hello, Firstly - I'm sorry about my level of ignorance! I'm a total newbie attempting to build a 40m2 extension to my flat in ICF. I'm having to use different contractors for the groundworks and the ICF, so I'm trying to get my head around how the two stages meet up...and realising that there are some pretty vast gaps in my knowledge! The way I currently understand it is that there are three separate concrete pours - filling the foundation trench / concrete slab for the oversite / the ICF walls. Is this correct?? My current plan was to have the trench foundations dug and then filled, then the ICF structure is built and filled, then the interior earth is prepared, insulation laid and slab poured. Assuming this is right, I'm struggling to see how they fit together when my ICF contractor is solely responsible for building the walls and then filling them; if the DPM has to intersect the ICF, shouldn't the slab be poured once the first row of ICF blocks are down - but doesn't that then mean there's a long delay to finish the ICF while the slab dries? Is there a much better way of approaching this, one that perhaps avoids having to hire out a concrete pump three times? Thanks for any help and sorry again if this is a very stupid question!