Mulberry View

This is a beam with the bolts in place. You'll see some toothed Timber Connectors. These were specified by my Engineer and were added to both stud positions in the end. The bolts were removed for installation of the beam in order to slot it into place. Once they were in place, I attached a large square washer with a double nut to the part that would sit in the core as an anchor. This is the view from inside the Nudura form, looking into the pocket from the rear.

Once this was done, I used a jig I made to drill the M16 holes in the Ledger, 65mm from top and bottom according to SE spec.

For those interested, here is how I installed my Timber Ledgers before my pour.... I used 9x2 TR26 boards, ripped down to 206mm to dimensionally match my 253mm Posi by the time they are top chord hung on the Ledgers. I first installed 4x2 Timbers to the wall where the Nudura props would go with hefty 6.7mm Timber Screws. The Prop channels were screwed on top of the timber using normal Nudura screws. The 4x2's were deliberately 200mm or so shorter than the Nudura channels, creating a pocket in which to slot the Ledger timber. Like this... Once this was done, I marked the top and bottom of the Ledger and planned the positions of the bolt fixings according to engineers spec (in my case no greater than 800mm, but also planned to suit the blocks and various other considerations. Pockets were then cut, with a 45° draft at the top and bottom to aid concrete flow. More to follow....

That's all understood Gus and I have a feeling you're right. My mind was set that if I am to leave the top of the concrete in a suitable condition for later adding wall-plates, that would mean working to get it nice and flat/level and by the time I've done that, I might as well have installed the wall-plates as it didn't 'feel' in my head as being much more work. I am a precision person, I would be gutted if I didn't get to hear that re-assuring flat-line beep from my laser level when the Posis go in, but that's a rabbit hole I've already allowed myself to go down. So, when installing the wall-plates, is it acceptable for them to only be touching the concrete at the fixing points, if packing is necessary? Or is there another way? Do I leave the concrete deliberately low and make up the deficit with my own cement/concrete mix later on whilst doing the fixing?

That looks good and not entirely different from my setup. I do not have a soffit as such, so do not have the oversailing timbers. As far as you having installed the wall-plates both during and after the pour, which was your preference and why please?

I wouldn't have done it, only that Alex had so wanted to check I hadn't missed the point.

I'm now part way into this. Did you put anything between your concrete and timber @Russell griffiths? @Alexphd1 used pieces of DPM I believe....

I've built my Nudura walls up to full plate height, with the idea that the Wall-plate will be installed along with the concrete and will match that height, essentially leaving the insulation all the way up. However, the plywood deck will, I assume, be attached on top of the Posis and oversail onto the Wall-plate. So, how best to fix it? I think my favourite way at the minute is to use Coach Bolts with the heads recessed into the Wall-plate, bolted on the back, then with a Nut/Washer/Nut at the bottom of the thread to anchor it if necessary. This would be pressed into the wet concrete and aligned with a laser/string. Of course I would not be able to cram the Wall-plates down once the concrete is cured, but is this necessary?

As an aside, I have managed to coerce my SE to agree a fixing solution of 2no M16 @ 800 centres cast into the concrete, this was achieved with the use of Toothed Timber Connectors behind the timber. I will post pictures of the way I'm tackling fitting the Ledgers pre-pour in case it helps others. Of course the pictures will be different and, for some, more amusing if my method fails. 🤣

My Architect had planned a service void in the ceiling, which I had planned to omit, not because I need the space, but more because it wasn't needed due to being able to run services in the Posis. However, you make a good point with the Plasterboard. I haven't even thought that far ahead to be completely honest. I had begun to consider Resilient Channel if I were to counter batten, which I'd seen someone mention in regards to sound transfer. Any thoughts on this? Speaking of Plasterboard, would you just use one layer? Or something else? I do like the idea of putting a service void in the ceiling below an air-tight barrier at roof level though, so will be looking at this in due course too. Thanks for your help as always.

So, I'm hoping to get these Ledgers up in the next week or so. My current plan is to get 9x2 ripped down to 206mm (my local Timber yard is happy to do this and I'm happy with the cost) and hang the Top Chord (47mm) of the 253mm Posi from it. That would give me a level finish above and below. Is this a bit OTT?! Should I be installing Ledger all round, even on the side walls? Or does the ceiling/floor just oversail the short gap to the wall?

I managed to build most of the first floor, up to 10 courses in places without the Nudura props. I now have them up and in place, that photo was a while ago. I have made support beams for the window openings. These are 18mm Hardwood Plywood, with 2no 4x2 Stiffeners (on end), spaced for Acrows. I have added a length of Battening Timber to each edge as I have to do some more reinforcement to the external face of each opening. Then the whole thing is wrapped in Visqueen to keep it from twisting and warping in the time leading up to the pour. I've used Acrows where possible and timber where it isn't. I still have to strap the sides in. If you look carefully, you'll see a 60mm slither of block over the top of the window opening which was unavoidable, so I plan to strap this in with a length of 4x1 or 6x1 screwed over the top of it and onto the battens I added to the support beam, to remove any threat of it blowing out during the pour.

So, this stuff? https://www.travisperkins.co.uk/plywood/18mm-x-2440mm-x-1220mm-structural-hardwood-plywood/p/767336 I get that for around £30 a sheet. Will I need to treat the edges?

I need to reinforce some relatively large vertical details before my Nudura ICF concrete pour. What is the best structural material to use for this? Will hardwood plywood stand up to the elements for a few weeks? I'm hoping to do my pour before Christmas, but I need to allow for this possibly being up into January. Some stuff I'm doing with timber, but I'd like sheet material for larger areas. (This pic is a few weeks old now)

I've increased the floor insulation from 150mm (designed) to 200mm. Do you think 150mm in the roof would be sufficient to provide an above-average performance? Is there any merit in adding rockwool to the Posi area? Also, do I need any additional air-tightness barrier beyond what is drawn?

This is the detail at the roof junction... 4 But bear in mind that I'm aiming to ring all the bells in terms of air-tightness, so if a further layer under the roof Posis is a good idea, then I'm all for that.

Pretty much as I thought, particularly the ceiling! Does the air gap in the perimeter walls contribute to the u-Value? Could/should I add a layer of rockwool in there?

My Architect specified a 50mm Service Void in the perimeter walls and a 25mm service void above the ceilings... Would you do this?

They just don't inspire me with confidence of a strong, bounce-free floor the same as hanging the joists directly onto a Ledger (Rimboard).

These are flippin' expensive, aren't they?

Thank you, I've asked my Posi supplier to quote on these. I'm thinking of putting a layer of DPM between the Nudura and the Ledger, leaving it long at the top so I can pull it down over the Ledgers to keep them dry. I might be worrying over nothing, but if I get them up pre-pour, it'll be months rather than weeks before the roof is on. As for the top chord hanging, why do more people not do this? It just seems really tidy and simple to me.

Just one thing, I'm guessing Kerto beams must be kept completely dry? Moreso than Timber? That might scupper my plan. @Russell griffiths

Haha!! I emailed Pasquill asking them if they could help with Metro beams!! PMSL. Explains why I hadn't heard of it and why Google had nothing meaningful to offer.

Thanks @Russell griffiths. Yes, I'm aware of the difficulty in propping. I plan to install the props on timber on the walls where ledgers are. I think I can use the props/timber arrangement to hold the ledgers in place (along with Timberscrews), I've had this in mind for a while and am yet to think of a pitfall. Good point in the straightness of the Timber, I need to research metro beams as I've not heard of them. I had hoped to not receive the Posi joists yet, so it's obtaining the beams if they are to come from the Posi people, but that's not insurmountable. Regarding the hanging, top chord was my preference it was only that someone raised a concern about strength with the joists hanging only from the top chord. Doing so would also help me to take the strength even further and into 147mm wide beams (8mm deflection) if I so wished). Why do some opt to hang Posi joists on hangers placed in the core as opposed to ledgers?

Shame for you, it's been a great resource for us and a community of friendly and interactive, similarly minded folk. We do not see food/holiday/clothes/toned thighs because we do not seek that content on our build account. It's not as bad as you've convinced yourself that it is!