Chanmenie

@ProDave I thought TS trade account gave 5% off, you sure it’s 10%

Yeah I found screwfix very competitive compared to online wholesale prices, managed to get an additional 10% discount which made them much cheaper than anywhere else.

Thanks @jack and @JohnMo I’m in Norfolk, I’ve not had my heating on yet, my current house is not as well insulated as the new one will be. according the the spreadsheet my heat demand was same as yours JohnMo 3.1K @ -5 Good idea with the waste water heat recovery Jack

@Gow did you mean 8m2 ? That’s a small room is it all walls and floor to ceiling ?

@jack how big is your house ? I'm aiming for .11u for floor .13u for roof and .15u for walls, not sure what passivehaus levels are. I’ll be 190m2 so might be able to get away with a 5kw or 6kw unit I used Jeremy’s spreadsheet and got a heat loss of 3.1kw but not sure how much to allow for DHW

@nod should that be CTD ? I’m looking for porcelain tiles but live near Norwich, there’s a CTD store near by.

I used the XR4000 hopefully someone more knowledgeable will be along to explain if 150mm @ 0.022 W/mk is better than 100mm @ 0.019 W/mk I’m guessing it is but hopefully someone will confirm. I went with 200mm in 2 layers of 100mm to aim for a 0.11 U value

That seems high, I was recently quoted £7000 for my chalet bungalow approx 170m. EWI pro Silicone render

You care to justify that comment ?

Hi John sorry to hear that, I wish you a speedy recovery I had a heart attack 18 months ago out of the blue, like you it was caused by a blood clot following a small arterial rupture Things like this are very scary, and make you feel very vulnerable. Good to hear you’ll make a full recovery.

If you are able to do ground bearing slab then forget block and beam

Insulated rafts are used a lost for timber frame and SIP builds as well as ICF

Yeah I have strip footings at 700mm but my ground was lovely firm sand and gravel

Why do you want it to heat up faster ? it will cool down faster a nice thick concrete slab works like a big storage heater and evens out the temperature fluctuations.

Why use block ad beam it’s expensive and less thermally efficient

I’ve just finished my ground bearing slab from bottom up 100mm crushed concrete compacted 23/30 mm fill sand blinding 1200g DPM membrane 200mm Celotex XR4000 two layers of 100mm all joints staggered and taped slip membrane UFH pipes 100mm fibre reinforced concrete ecFlow why have concrete and screed ? That’s two floors you only need one

As Peter said it’s unlikely to be copper underground, dig a hole outside, you’ll probably find it’s blue or black plastic unless the original house is very old then it could be lead. It will have been joined to copper somewhere.

I had a conservatory roof panel explode whilst being fitted, my son in law was directly under it, but he escaped without injury thankfully.

Hardcore, type1 or clean crushed concrete, compact that with a whacker plate then blind with sharp sand or fill sand which is cheaper if you can get it. then DPC then insulation

Company called Subteno the boss is Andrew Dye, if you ask for him tell him I recommended them https://www.subteno.co.uk/

If 200mm PIR was specified was that what you paid for ? I believe 200mm PIR would be considerably more expensive and take much longer to fit, therefore the builder has made quite a bit more money by using mineral wool

and once it gets through if you pour the concrete can it still get out ?

Hi Guy's So i'm putting the hardcore into the foundations on Saturday, followed by blinding then DPM, insulation, slip membrane, UFH pipes then concrete. Obviously this wont get done in a day so are there any issues if it rain's in between these stages, with the DPM being what it is, is there a problem if I get water under the insulation ? I'm hoping to put the DPM, insulation and slip membrane in in a day, then the slip membrane should hold any rainwater that falls, but will it cause any real problems if any gets through before we pour the concrete.

That should work, use double sided butyl tape on the joists which will seal the screws that should make it very air tight

I’m doing the same, fibre reinforced ecFlow concrete, a little more per m3 but I saved £1k on rebar mesh, plus the time and hassle of fitting it. http://www.easternconcrete.co.uk/wp-content/uploads/2018/07/GDA-443_EcFlow-Nov2017.pdf