Selexus

I'll maybe put all this in another thread. Concious of hijacking this one.

66 sheets of 4.8x2.4m 1 top layer 1 bottom layer.

Greenraft (great company) SE specified the reinforcement to mitigate anything up to a 5m diameter void appearing under the raft.

Plan? .... What is this plan thing you speak of? 😊 Yes, definitely overkill by the SE. Nearly killed me doing 66 sheets of A393 and 2.5 tons of reinforcement ground beams, solo.

250mm thick. 15 lorry's 😢 I paid for the pump, they brought all the other kit. I cut the contraction joints 36 hrs later. It'll rain later today and it's to big to cover so fingers crossed 🤞. If it all goes bad then plan B is a 2-3mm epoxy finish.

I've moved to Devon, but I'll certainly DM their details.

Just had 400 sqm of raft foundation poured leveled and power floated, all in one sitting. Guys turned up at 6.30am and left the following morning at 3.40am. Really good job. £4k.

Thanks Yes already had that conversation with them. It's one of the few aspects of this build I'm not doing myself. We also discussed dry shake surface harder powders for colour enhancement. although that decision is yet to be settled. Still trying to get a delivery date on my pre-fab ground beam cages 😡

No definitely not. Warehouse is perfect. We'll have rugs and other stuff around that will soften the look and feel of it.

Polished concrete. We'll make a feature of the cut joint that the SE has now agreed to. Inlay it with a brass strip or something.

So... Had the conversation with my SE and after some discussion we settled on a standard cut control joint at these locations. The dowel joint was mainly specified to potentially placate the over zealous requirements of warranty providers that the SE has recently come up against in recent jobs. The SE has no issue with standard cut joints as there is minimal potential of differential settlement. He mentioned that contraction was the major concern, and if was ok with the cut joint opening up slightly over time, then he had no major concerns. We have agreed to present a united front (from a risk and technical perspective) to said provider if they question the use of control joints, rather than dowelled joints. The more I talk to him, the better I feel about this work.

Don't put ideas in my head. 😆

I don't disagree, but how do i get the SE to agree to this ?

Blue dotted lines are the 2 joints specified by the SE. I'm happy with the whys and wheres of these, as the slab is 42m long and NEEDS some form of expansion control. What I'm looking for is a recommendation of a product (preformed joint) or method, that would allow simple construction of this joint prior to our single pour (90 cubic meters). Thanks S

Thanks Gus. I did have a chat with him and his explanations made good sense, although on the risk averse side His reasoning was very similar to what you have pointed out. Ease of build (we have a fixed flat base - existing concrete slab) and so incorporating all elements into the raft, and making it capable of surviving differential movement (like that's going to happen 🙄) of this existing concrete, is how we ended up with the 250 slab with integral ground beams. He certainly has put the hrs in thinking about how to design AND how i am going to build it, so fair play to him.