It's been a wile since the last blog entry and I didn't expect to have gone through yet another contractor by this stage but that's the way life goes!
We had some good progress with the basement floor walls going up and getting poured without a hitch. We moved on to the basement roof which is a terrace for the lower ground floor so was propped with acros (decided to buy 50 as can re-sell later). That also went well - aside from some issues identified by the structural engineer. Due to a delay in the concrete pour (don't ask), managed to get a local firm in to make up the shuttering for the exterior stairway so poured them at the same time as the basement roof - not really saving money just getting it done a bit earlier.
With that done we could get no with some backfilling on the sides of the building, brining up the drainage pipes from the soakaway and building some planters between the side the basement and the boundary - reusing some of the sleepers from the retaining structure we built along the boundary. Also meant we could get some blocks in to the other boundary wall and close in our neighbour - she's been great and very understanding!
After applying the waterproofing and a few weeks we were able to properly backfill behind the basement. The engineer required more granular fill than the beautiful sand we had removed so that hurt a bit but never mind we cracked on with that and backfilled against the eps sheets we laid against the double drain which was against the waterproof membrane. This took a lot of time compacting in 150mm layers but we had a big excavator on site to help and a few bodies.
With the backfill done we could start on the ground works for the lower ground floor. Unfortunately a ground worker though a boundary wall should come down (I wasn't on site) so that made a lot more work - was the remaining part (about 8m) of a 20m long wall so more to get rid of and more to rebuild (he didn't last a lot longer). As this floor is below street sewer level we installed a1.5m x1m pump station for foul water/sewage - the upper floors go direct to the sewer so we can last a while if this get blocked up - though it does have 2 pumps, an alarm etc. Issue really was that it had to be pretty deep due to the distance from the furthest bathroom - though the groundworks guys did a great job with that. We found that a large tree we had felled (with permission) had it's stump in the way so a day was spent getting rid of that -managed to find a neighbour to take it + some off-cuts of timber!
You can see in the pics some decent size I beams we installed to make a king post wall retaining our neighbour's new fancy house - the beams were 9m long so 6m in the ground and 3 out to retain the excavations. Luckily I could call upon the firm I used for the earlier retaining king post wall who happened to have hired in a great new machine which they used for 2 days to make the holes and we then used the 13T excavator to drop the steels in place - this was completely heart in your mouth stuff. The steels were too long to be lifted so the guys cut a wedge in them 1m down from the top to wrap the lifting chain around to get more height - worked great. A bit of concrete later and we had 4 solid steels which we could install the sleepers in to.
Rest of the ground works just took its time, we're 3.5m below ground level so all materials had to be sent down a home made chute but more problematic was the removal of 160T of additional excavations from the trenches and final levelling. how do you get that up 3.5m? We hired a long reach HiAb with a clam shell bucket and paid extra for a tipper to be loaded at the rate of 1 per hour. Took it's time but we got there eventually. We still had some final trenches and drainage right at the front of the site which of course resulted in 30T more excavations which we put in dumpy bags and got the HiAb back to lift out and put in a tipper - though kept 10 on site as a safety barrier and to reuse for backfill later.
And the long boundary wall - well we re-built that much stronger than it was and also a little higher to fit with a future stairway - not looking forward to the rendering cost for that !
So we're now ready for the concrete blinding layer and then we get the steel fixers in for 10T of rebar for the next slab. I hope it gets easier after that! and hope we keep the current team for the duration....