MustyandConfused

Thanks all - so it sounds like it’s not weird, but is unusual. Will try to get straight answer from them tomorrow.

We are in the early stages of our extension. builder has dug and poured the strip foundations to the structural engineers spec. All good. my expectation and understanding was the next stage would be building the first few course of the cavity wall up to at or around dpm level. Then they would look to prep and pour the concrete base within that ‘perimiter’ (including 130mm layer of hardcore, sand blinding, dom, 130mm insulation, more dpm and then pour the slab on top. however builder is suggesting they could prep and pour the concrete slab before building up the cavity wall (by using shuttering). This seems weird and I can’t get my head round it. is it weird? 😃

Thanks. Should have mentioned conservatory was built with planning / building standards permission (although 20 years ago). I actually still have the paper plans for it (very unlike me!)

Another pic

Have structural engineer coming out in a couple of weeks for site visit related to our application for an extension. He’s asked for two trial outs to be dig to expose existing foundations 300x300 and dig to 50mm below underside of foundations. I thought I’d give it a go - how hard could it be, right? 😃 so first pit was to be in corner where our conservatory (built 20 years ago and to be demolished to make way for new extension) meets the original house wall. I was expected to hit the top of the foundation about 400-600mm down. However, if I’m looking at it right, it’s only about 250mm below ground level - as are the founds for the conservatory. Both seem to be around 150mm thick (which is what I expected). in addition, the house founds seem to be brick rather than a concrete strip (again to my eyes at least). House is an early 1930’s bungalow. a) am I looking at it right - going by the pics? (I put the wooden skewers in to mark where I think bottom of founds are) b) is this likely to be an issue re new extension?