bradders3109

Hi Adam I did look at Blowerproof but it was more expensive than passive purple.

Hi jfb we are externally insulating the current house and then building an extension with nudura which shouldn't need an airtight membrane.

Hi All, I have finally reached the stage where I need to apply an airtight membrane to the interior of the original house (225mm solid wall, 90 square meters). I don't like the thought of loose membranes and have been looking at passive purple as a sprayed solution. This is coming out expensive and I got to thinking whether a tanking slurry would work as an airtight membrane or any economical alternatives that others have used. thoughts would be very much appreciated.

Thanks for the replies gents. The reassurance and encouragement makes a massive difference to a Virgin self builder. I’ve looked at it again this morning and it’s worse than I originally thought. However 20mm of sharp sand will level it up and cover the eyesore. The positive is that the slab is drying solid although the depth will be variable between 100 and 120mm. Thanks again.

I did screw rails to opposing walls but with trying to mix, barrow into the room and tamp level it got in front of me. The missus was filling buckets ready for the next mix.

lager mate. can't face the claret tonight.

I thank you all very much and am feeling a little better already. I won't try self mixing a slab again though. sharp sand under the celotex it is then.

Would you just leave the sharp sand loose or mix it with cement and SBR to form a screed?

DPM is under the slab but laps up the walls by another 400mm to take it above the celotex and screed.

Already on my fourth bottle ☹️

does it not need to be level for the celotex?

Hi James there will be UFH on the celotex and then 65mm screed.

Hi all, I have today attempted my first concrete slab. It isn't a big room about 2.75m by 3.5m . We are replacing a suspended timber floor so the walls are already built which made things difficult. It was a day full of choice language and despite the best efforts of myself and the ministry of fun we have made a bit of a mess. The result is a slab that rises and falls by up to about 15mm in places. I am thinking that I could go over it with a thin screed or self levelling compound but don't know if this is a good or bad idea. the slab will be covered with 150mm of celotex and a final screed so won't be seen but i'll always know that it isn't level. Is there a product that I can use on a newly laid slab to level it and cover imperfections. Your help and suggestions will be greatly appreciated.

Hi Dave if you’re still interested I’ve been quoted £220 + vat for the service. I think it depends on the build/renovation. Aviator have access to the whole range of products from saint-gobain companies and whatever they quote must be honoured. Jewson online process to the public are extortionate but the do a self build account which reduces the prices but still not cheap IMO. Best to phone local branch for best prices and try to negotiate.

sorry I'm a new member to this forum and only just seen this. I qualified under BS 7671 17th edition and the reg then was 631.3 and App 6 as in the graphic. I believe under the 18th it's 644.4.201.

I have recently approached building control to see if they would sanction the new 350mm Amvic block which is pending BBA approval. They have informed me that they will not sanction any building fabric which does not have full BBA certification. Whilst I accept this stance the surveyor also states: "I have no issue with the use of different building products but from a professional aspect would question the use of mixing construction techniques across a single domestic project. I would personally advise adding the extension in cavity construction as per the main original property." There are two issues I have with this: 1. The original house is a 225mm solid wall so he obviously hasn't looked at this properly. 2. Is he really advising that older properties should only be extended using the techniques employed for the original build and new building techniques should not be embraced. Anyway this is only his advice which I will choose to ignore. Additionally I have now lost confidence in the LABC and will instead use Stroma for the building control element of the build. Not really a question here but just thought it worth sharing.

I know that feeling : (

Hi Happy Valley There is a thread where lots of prices are discussed.

My compiled quotes are as below: *Nudura are requoting because there is now an additional wall to be constructed in ICF. I will post the new quote when it comes in. The amount of concrete required varies between 21m3 and 24m3. This is either down to misinterpretation of the drawings or different size cores in the ICF. The build is an extension to a detached house as per the attached diagram with ICF highlighted in blue. ICF Design.pdf

Andy I understood that Thermohouse was from Ireland but maybe wrong. Izodom are from Poland and you are quite correct the shipping costs are nearly £2000 but the block price counter balances this. My concern is that they don't have BBA certification as they are covered by EU certification. I've emailed my local building control to see if this is an issue with us having left the EU. My Durisol quote came in and was double the most expensive EPS block and three times the cost of Izodom (Not including the shipping costs).

After renovation our property will have externally insulated 9 inch solid walls with and internal air tight membrane. The extension will be ICF (not sure which yet). Floor slabs will have 150mm insulation and roof will also be well insulated and airtight. We will have MVHR. Following the article that LSB referred to I'm still undecided about ASHP or Gas boiler. As you say we can't control the cost of gas and electricity. Also there is a plan to phase out gas boilers so I would imagine that as time moves on there will be measures taken to 'encourage' people to move away from gas. This could be a 'green' tax on gas or something like that. ASHP is the future proofing but maybe that could be a later install when the price comes down.

I read the same article and have a similar dilemma except that the property that I’m renovating does have mains gas which means that I’m leaning towards a new gas boiler. Interested LSB what you decided?

I'm not hung up on transport costs. i'm looking at the entire package and where I might be able to save money. For instance if company A is charging £2000 delivery from outer London to Norfolk I might be better off hiring a 7.5 tonne wagon and collecting myself. Only by viewing the various elements of the build in isolation is it possible to make the little trims and cost savings that in the end add up to a significant saving on the whole build cost. I wish that I had a bottomless pit of money and could just crack on but I don't and every element needs to be costed and if at all possible trimmed. For me this process, having established the style of the property, has three counter balancing elements: Cost Ease of build Energy efficiency and quality of completed build Look after the pennies and the pounds will take care of themselves.

absolutely and when you are confident that you are managing the details airtightness etc. One of those details that contributes to the finished product is the U value of the walls along with the U value of the floor and the roof.

My transport costs to Norfolk have been all over everywhere: Nudura £250 Warmerwall 3538 Izodom £1906.50