Selexus

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.

Here. Left pipe is the hot return (from the local ensuite hot manifold) middle is the hot feed (now run in) and right is cold feed. All 20mm Pex-al-pex. This ensures hot circulation at the main manifold (center of the house) and therefore short runs from there to each en-suite manifold.

I used these on my last house. Would not go back to sand and cement, or other methods. So easy to install and level.

Hi All, Now that my UFH pipe placement and other such incidentals have been settled I'm turning my thoughts toward how to create the 2 x 6m long expansion/movement joints in the 250mm raft, that also have 20mm sleeved dowels through at 600mm intervals. Never done it before but I'm thinking some aluminum angle supporting 20mm compressible foam, through which the dowels poke and are supported by rebar either side ? Suggestions very welcome 🤔 Thanks

Not yet, but it's a good shout. Don't want a bit of rogue concrete blocking a water pipe and giving issues later....

Oh yes.

Its Sopera XPS. Interesting stuff to work with. I've bought a hot knife gun and have routed all the first fix pipe and conduit into the top of the insulation.

On top it is! The partner will be happy to hear that 😆😉

*selexus goes to look at Samsung watch step app*

Bugger.....hadn't thought of that. It's a 57m walk..... Scooters....electric scooter....that's the solution 😃

I'm with you Steve. I challenged our SE about the 250mm slab and he said his calculation fell apart at anything less than 250mm. On this design every 25mm of concrete is £1k 😲 The exiting concrete (and the substrate) is absolutely fine (as confirmed by a Geo Technical survey). Blinding has been dispensed with as the existing slab has a 10mm variance across it's entire 57m length with a good surface finish (used to be a chicken shed). I'm committed to this design now as any more delays and my build program goes seriously off track, but I'm definitely with you on the over engineered observation. On the bright side, I should be able to use the telehandler indoors 🤣 Anyway i've just sent the SE an email asking about the reinforcement build up as to my sums we have 170mm of reinforcement with a 50mm bottom spacer, which leaves me with only 30mm of top cover (i think) 🤨 Why is nothing every simple.......

Sorry Gents, stepped away for a little trip. Back now. Yes Nick, 200mm of XPS under. On top of the existing concrete slab, that we're treating as subbase. Then a flat 250mm reinforced slab. This detail should provide more context it's the same section of H-H but without the reinforcement detail. Also an edge of raft detail to bring more context This is the GA for those that are wondering about shape and size of building. I'm definitely leaning towards clipping to the top mesh. Giving this some more thought it makes life much more simple and I'm sure there will be very few occasions where i need to drill the slab, so.... Thanks

Yes fair points. Due to site conditions i was looking to screw the ICF bracing down onto the slab to support the walls during pour. I'll figure something else out. Correct on the reinforcement. I think if i wanted to i could run the pipes along the bottom layer of mesh (before the cages are dropped in) and loop then under the bottom layer at the point they cross the cages, clipped to the underside of the mesh. Lower the cages in and continue the buildup. Or just go on-top as nick has said 🤷‍♂️

Yeah..i see what you mean...sadly that's not how the slab is constructed. Is a section of one of the main ground beams.

Hi All, I'm after a bit of advice on running UFH pipe across my insulated raft foundation. As a lot have done my plan is to embed the UFH pipes in the slab, clipped to the mesh, and run back to the centrally located Manifold. I had planned to clip the pipes to the bottom layer of mesh, and the put the chairs and top layer in, so somewhat protecting the pipes and having at least 200mm of concrete above to safeguard against hitting a pipe if a fixing needs to be driven into the slab. However my SE (who has been great) has decided to design an aircraft carrier and I'm now presented with several ground beams the support the raft and some of the point load areas. These create smaller pockets that i have no idea how to route the UFH pipe into as the ground beam cages create an obstruction to routing the pipe. A section of the raft plan is below - I could clip to the top layer of mesh, but that means i have no insurance against someone driving a fixing into the slab and hitting a pipe ! Has anyone any ideas how i get around this ? Thanks S

Yup. Me and her, with help from friends along the way. Contractors will help with Steel and electricals, and a few other bits (ICF pour, etc). 102m of foul drainage installed already. Waiting for Insulated raft kit for the next stage 😃

Hi All, Had a chat with the SE this week as part of the ongoing detailed design (BCO approval drawings) and he's keen, as am i, to get a ground survey done on our plot before we commit to a foundation design (currently insulated raft). Anyone have a recommendation of a good Survey company in the South West ? Thanks

Having now looked at the Thermofloor option, I'm certainly keen to know more. Was it a straight forward installation (i'm assuming you had ICF walls as well ?) ? Did either of you have any additional structural strengthening required ? possibly over large window or door opening ? I need this and am keen to understand if any flex in the roof/deck is present ? I'm sure our SE will want to specify additional steel to support our main 12m openings. How were Thermohouse to deal with ? Delivered on time? good support? Thanks