Would large format 300mm concrete Lego blocks with thin set mortar and EWI be viewed any differently by Building control than a solid standard block wall with EWI?

Thanks

.....not used.... ?

<blockquote><cite>Posted By: Peter_in_Hungary</cite>Wot Mike1 said +1

However builders here don't like using concrete blocks because they are too heavy, - OK for the first 2 or 3 rows but then the weight of lifting them up (as opposed to say porotherm or similer blocks) becomes arduous, the work rate slows down and by mid afternoon they go and find something else to do because they have had enough.</blockquote>

I give up with builders which is why I am looking at these. Quotes have been ridiculous work is not in short supply.

I would stack these in 2/3 days with a farmer and machine. They are large format but only 300mm wide. We built a incline gravity retaining wall with the 800mm wide versions. This should be easy by comparison.

If I had any block laying skills I would not consider these. But it is a cost effective way for me to get a shell up quickly.

ICF is not a option. My site is elevated above a footpath and road.

<blockquote><cite>Posted By: Peter_in_Hungary</cite><blockquote><cite>Posted By: Kev.k</cite>I would stack these in 2/3 days with a farmer and machine.</blockquote>
If you have mechanical handling machinery then the weight problems of course go away</blockquote>

For me it is the quickest and cheapest way to build a house. I appreciate it wouldn’t be for most people.

I also like the idea of a 300mm thick concrete house with EWI over a very basic (my budget) 140mm timber frame.

Posted By: Kev.kI also like the idea of a 300mm thick concrete house with EWI over a very basic (my budget) 140mm timber frame.

Where does the 140 timber frame come into the construction? Standard EWI is glued straight on to the wall, rendered over with glass mesh incorporated then a weather coat of thin film acrylic (or silicon based) render. Very DIYable.

You would finish up with a house with a high thermal mass !!

I had a quick look at the buildhub thread mentioned above - there was some support but most were suggesting a more standard (for houses) approach which for your reasons is not appropriate.

You will need the support of the manufactures, the BC and your SE

By the way if you make sure that the Html button is selected (below the comments box) then the quotes come out in the customary blue box.

<blockquote><cite>Posted By: Peter_in_Hungary</cite><blockquote><cite>Posted By: Kev.k</cite>I also like the idea of a 300mm thick concrete house with EWI over a very basic (my budget) 140mm timber frame.</blockquote>
Where does the 140 timber frame come into the construction? Standard EWI is glued straight on to the wall, rendered over with glass mesh incorporated then a weather coat of thin film acrylic (or silicon based) render. Very DIYable.

You would finish up with a house with a high thermal mass !!

I had a quick look at the buildhub thread mentioned above - there was some support but most were suggesting a more standard (for houses) approach which for your reasons is not appropriate.

You will need the support of the manufactures, the BC and your SE

By the way if you make sure that the Html button is selected (below the comments box) then the quotes come out in the customary blue box.</blockquote>

Sorry I did not word that well. I meant I would prefer a block house to the alternative of a basic timber frame.

Posted By: Kev.kSo you think it’s not a good idea to ask the same question on a different forum? I disagree.

Actually, if you look at what I wrote that isn't what I said. I suggested a concrete course of action that is better IMHO, and I asked a couple of specific questions that you haven't bothered to answer.

Oh and yes, please use the HTML button.

Posted By: bhommelsAlthough it does not answer your question about whether building control will like it or not, this is the green building forum after all, so:
The CO2 footprint of the concrete block house will be enormous: producing a kg of cement releases 0.9kg of CO2. A timber frame house is constructed out of renewable material, so it could be argued its CO2 footprint is (close to) zero.
It would be an environmental disaster if all new houses were built of concrete LEGO the way you propose.

The blocks are usually made from surplus returned concrete. I would not propose all houses be built this way.

My site isn’t suitable for icf and I’m being quoted crazy prices by builders.

The green aspect is that the house will have good thermal mass to retain heat and be well insulated.

So much of this thermal footprint stuff is rubbish in relation to how most timber frame are built. The frame is made offsite then transported many miles by a long loader, then craned into position onto concrete foundations. Usually have a block skin built too.

Most are about as airtight as a flat tyre and aren’t built very well. The passive timber frames are different completely but I’ve still read varying opinions from owners. Many say they are not airtight as claimed, and that the tests used are flawed.

Concrete is essential in the process of building a house. Using surplus returned concrete is “green” imo.

I'm intrigued as to why your site isn't suitable for ICF? Being elevated above a footpath and a road needn't be a problem. Are you worried about form failure during pour?

Failing that, if it is block laying skills you need you can find no end of bricklaying courses, get yourself on a week's holiday to one of them and buy some profiles and get cracking on it yourself if it is a skill you'd like to have and can spare the time/money for the training. Block on the flat with EWI?

Durisol/ICF - to limit risk only do 3ft lifts and pours. Likely to get a better overall build as well with fewer voids. Don't let that put you off. At one stage I was hand mixing and pouring ICF forms.

Your big block idea may well work very well for you, couple of things to be aware of:
1) Opening sizes - are you going to be able to easily fit suitably sized doors and windows into the apertures you will be able to create? How does this tie in your window and door sizes and locations in your planning permission? Think about lintel sizing in your standard unit sizes, they may be quite deep and most houses will require relatively shallow lintels
2) DPC - you will need to think how to detail this. I would suggest using liquid DPC such as BlackJack
3) Opening detailing - need to consider DPM/cill detailing and what it will look like to be watertight and avoid excessive cold bridging, especially with externall wall insulation (which may be helpful in addressing item 1)
4) Mortgagability - might need to consider a specialist mortgage, last thing you want is a surveyor coming along to release monies and refusing as it isn't a standard masonry wall. Could be awkward to say the least.

However, all the above could no doubt be overcome - we haven't seen your plans, your site or know your skills - you know all three! All the best with whatever option you choose, be good to hear what you decide and how you get on.

I agree Jamie is a good guy. If I could afford to, I would let one of his teams do the whole thing. Isotex is a great product. But my site makes it a diy risk I can’t take. A burst/collapse could actually kill someone so it is a very unusual location. Elevated 2m above a footpath and road.

If I had a site without these issues I would have ordered isotex already.

I’m on a tight cash budget with no additional finance.

My skills are limited. Only experience is with concrete Lego blocks. That was a incline gravity retaining wall with a 1.8m wide base. A house would be simple in comparison.

The blocks are so varied in size that doors and windows should not cause a issue and they make steel cage reinforced lintel blocks up to 2.4m long.

I’m also not the first to do this. There is a equally crazy guy in Holland :)