PeterW

Just get some end caps for the PEX (probably 16mm) and then cap off one end of each loop. Now put a 16mm/1/2BSP tap connector on the end, put a pressure tester on the 1/2” and pressurise to 2 bar. Lock it off and then wait. It will drop fairly quickly if there is a leak, check your fittings with soapy water then move on. Cap each pipe as you go and the pressure will be fine for pouring screed.

I’m slightly confused. What is providing the heat to the UFH and rads ..?? It can’t be the Nibe as it wouldn’t be able to cope (or is that the issue..??!) as its output is far lower than you would need. I would go for standard ASHP and then put a centralised duct fan unit on the existing extracts to reuse them. Putting proper MVHR isn’t going to work unless you put new fresh air ducts into the house via the unit and remove a lot of the fresh air vents.

It is - but they are fag packets ..!!! Think about buying DIY Kitchens and adding on the utility - wish I had done something similar on a previous job and not ended up with a Howdens/DIY mix ..!

That’s very shallow. What tiles have you got that work that low ..?? I’d be making sure that the laps are taped and that you have a suitable overlap - 4-500mm wouldn’t be unreasonable.

So do a rough budget of £10k kitchen, £5k bathroom, £3k each en-suite, £2k utility. That’s your big blocks of supply and fit at roughly £23k. For the remainder you can estimate £200 a door, £150 per room for arcs and skirts, £500 per room board and skim. Add £250 per room for basic decorating. Then you can multiply it simply by number of rooms to get to a budgetary value. Don’t forget to include hallways (just ignore the doors unless they have them too). So in this case a 3 bed with lounge, dining, kitchen etc would be 12 rooms so ~£13k to add to your £23k so with contingency of 10% I would be looking at £40k. If you want to use parquet then beware it can be expensive to both buy and lay. You can soon spend £30/m buying second hand and then £30/m laying and £15/m finishing it. Ask me how I know ..... ?

You’ll have to cast that in two sections and use rebar then as you won’t be able to shutter the inside without some real challenges. There is also a huge cold bridge as the bottom of the pit has no insulation. Can’t see why the top deck if it’s only a chill out area needs to be 150mm - that will save you about 1 1/2 cube of concrete.

Welcome ..! Are you going to push the spec a bit on standard and go for a wider cavity to get increased SAP score and lower heating bills ..??

Nothing I could find other than Russian ones ...

3-400mm at most assuming you hit solid ground, then just dig out the strip for the founds and back fill with clean hardcore once the brickies have got you to DPC level. What has the SEng drawn for this as a lot of statements both SEng specs on those drawings.

Not unless you’re at passiv levels of wall thickness where having a 300mm cavity they start to become reasonably priced. As @Declan52 said - find the places you can add insulation or pay more for some better tapes etc for airtightness.

Ok so you may want to pocket the RSJ into the wall and give yourself enough room to put a Jack under the end of the RSJ in the wall. Then insert it, Acros on boards under the beam and hold it tight and then it’s slow lift to raise the sag out of the joists using the RSJ, tightening the Acro’s as you go. Keep swapping ends, when it’s up as far as you dare then you set the padstones in and wedge with slate. Leave the Acro’s in for 48 hours til the mortar goes off.

Bare wood should be primed - oil based primer is better but needs a few days to dry properly. Then putty and glaze.

@SeanDean What’s the total area of the garage floor ..?? Also, what is the construction of the step between the two floors ..? That may have to be cast first or constructed differently. Added couple of questions after talking to my engineer ..!! - What is the load on the area marked “Pit for lift” - What is cross section across the pit area. How is it tied to slab / depth / etc and how tied to foundations.

They will not be using SPON major works which is probably more comparable. It will be priced off the small works pricing.

Acro’s are Acro Props, not Acro lifts - they are not designed to be used to lift loads. How have you ended up with 30mm deflection as that will have left some pretty substantial gaps above if that is the case ..?? If you have to lift then it is much better to use a 10 or 20 tonne bottle jack on a platform to provide the lifting, and then support with an Acro as you go, working along each joist lifting no more than 5-10mm at a time.

So you have 150 litres of water, a 175kg bath and a 75kg person, or 400kg load, at a point on a number of joists. Standard loading is 1.5kN/m2 which is only 150kg so you would need to double up below the bath anyway or reduce the spacing of the joists. The issue usually is that unless edge supported, a bath imposes a point load at 4 or 5 points in a fairly small area with the feet so anything you can do to spread the load is preferable.

it’s a 3 or 4 bed house so catering for 2/1/1 would mean having hot water that can cope with 4 showers x 8 minutes at 12l/min so you will need all of that 250 and more. ASHP can’t recover a tank as quick as a gas boiler so upping the size is negligible. The “waste” is an additional 7W/hr between 250 and 400 litres so 168W/day or £9/yr assuming direct electric. Heat would also be lost into the house so would directly reduce the heating demand of the house by the same amount. Developers work to a bare minimum to maximise profit - I would never use a developer house as a benchmark to aspire to ..!!

Sharp sand, laid dry and levelled into the hollows. Then Celotex, slip membrane and screed.

375 cubic metres is about 550 tonnes so 17 tonne lorries at £200 a lorry would be 45 bulked up. That’s your £10k or so. JCB and driver for a week is £1200 round here, can load a wagon every 30 mins so 12/day from day 2 onward. Even if you got a 13 tonner to do the excavation as it’s hard ground, that would be £1700 with driver and delivery. All done in a week max, change of £13k.

Yep likewise - really helpful and they do a variety of products and thermostats from the cheap and cheerful up to the WiFi enabled ones. Mat is quicker to lay - prime the floor, let it go tacky and then roll out the mat. If you’ve got the height then a quick layer of self levelling over the top and you’ve got a perfectly flat surface to tile over 3 hours later.

wrap over is fine - bead of lead seal would help keep it watertight on the overlap

Half way through is ideal. If you want belt and braces ask the concrete company to put fibres in the mix and it will be bombproof.

I hadn’t even clocked that ..!! @SeanDean who has specified two layers of mesh in that slab ..? One is more than adequate, you’re building a garage slab not a motorway bridge ...

OK - was on the basis of a 4 bed / 2 bath shower type setup and people wanting lots of hot water. Losses are small and they are into the fabric of the build so it doesn’t make much odds so I would go with a 300 litre which I think is about the smallest you can get a large surface heat coil and two immersions in to. You’ve got a pair of immersions in the tank - just use them to boost. No Willis required.

12mm CemBoard or MagPly would do that overlay with support from the battens but it’s going to be eye watering in price. The NoMorePly product can replace the whole floor and it’s good but again it’s expensive. 6mm ply won’t work in the way it’s been used by the OP as it’s far too flexible.