mr chris

new build possibly ICF

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Hi, I'm planning a new build as an end of terrace next to an existing 1950's solid wall house with external insulation in Bristol. I'd like to make it fit for the future, so definitely not cavity wall construction with it's myriad of inherent problems. 

 

I'm attracted by ICF as it is so easy to achieve high insulation values and airtightness, high internal thermal mass, as well as good sound isolation. However, I don't know which of the many competing systems to consider, particularly for builders who haven't used it before!

 

Any advice would be very welcome.

 

Chris

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welcome to a new adventure

 

how much of it are you doing yourself?

that is first question

 

and is it going to be a continuos job once started

basically two different types 

poly block types and  then woodcrete types

 poly block there will be at least 10 different systems ,all of which will require bracing 

woodcrete types

there are  3 

durisol ,

isotex 

velox

after studying for well over a year

I am leaning towards woodcrete type ,as I may need to stop  at some point  until i get more funds - need to sell other bits  of site to complete -don,t want to sell my present house till this  is done

which is main reason I am not considering TF or SIPS

brick and blocks  too heavy for  this  old man to work with 

all types can give you what you want -

 I suppose you should start with a design and send it off to different suppliers to quote for supply of bits or fully built shell

 

 

 

Edited by scottishjohn

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Hi Chris,

 

Welcome to this great forum and good luck with your build.

 

I am also a newbie going down the ICF route for my basement and was on the verge of attending some courses with some of the providers before the Coronavirus struck.

Hopefully when we get back to some sort of normality you'll be able to do the same and get a feel for which product you'd like to use. The build shows are also very useful as they often have demo's from some of the ICF providers.

 

Best of luck

 

Alan

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Nothing wrong with ICF or cavity wall

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Nothing wrong with cavity wall at all but it is harder to achieve U values close to 0.1 and levels of airtightness associated with passive house.

 

@mr chris, when the risks of socialising are reduced you're welcome to view my ICF new build just outside Bristol. The ICF is still on show inside and out and will be for a while yet.

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1 minute ago, AnonymousBosch said:

I get the feeling you are sorry you used durisol-

It seems to be used the world over without the problems you had

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Thanks for the replies!

 

In answer to @ScottishJohn, I'm hoping to use some builders to get the construction done quickly, but I'll be managing the project. It's all happening in one go. Apart from the potential for pausing construction, what are your thoughts on the polyblock vs woodcrete decision?

 

Regarding cavity wall construction, that really is another topic, but I've been working for the Cheese project in Bristol doing thermal imaging surveys of lots of different houses, and this is a very good way of getting to understand the real thermal performance of different building methods. When you measure cavity wall buildings you discover that they really don't perform well at all. Rather than go into all the details, here is a link which discusses it if you are interested: https://www.designingbuildings.co.uk/wiki/Defects_in_dot_and_dab. It references dot and dab plaster finishing inside which essentially shows up the difficulty of preventing cold air getting throughout the structure, but even without this, external air usually finds its way into the ceiling to floor voids, under the skirting etc. The problems are all hidden unless you actually measure things with a thermal camera and air pressure fan, and they are very difficult to rectify. It's a bit of a scandal really.

 

Anyway, what I've learnt has convinced me that the way to go is solid wall with external insulation, or ICF.

 

Thanks for the offer @Willbish, I'd love to see what you've built! Did you use anyone experienced with the ICF system? And which system did you use?

 

Durisol was recommended to me and I had a look at it. To get the sort of insulation factor I'd like, the walls come out at 400mm thick including internal and external finish. 

 

Thats some very extended list of  info @AnonymousBosch! To summarise, get your design right before starting and use then right workmen?

 

 

 

 

 

 

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We are in Cirencester if you want to look at a Nudura icf house, blocks still visible inside and out, 

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Hi @Russel griffiths 

 

Thanks for the offer - I'd love to see your house!

 

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On 02/05/2020 at 11:18, mr chris said:

what are your thoughts on the polyblock vs woodcrete decision?

If I go ICF --lots of things s with my site which are to be decided yet  

then it will be ISOTEX  -durisol only if they are significantly cheaper- the width of blocks vary quite alot -so you need to decide which side is going to be flat as you build-and the surface rinnsh is alot more open than ISOTEX

 Isuppose other big hting is that the woodcrete are pourous ,so the concrete drys out -sets quicker than poly especially if its a sloppy mix -so bottom firms up quicker and less hydraulic pressure to burst things if you really hammer on pouring quickly

 

close second is poly system   ISODOM sold in uk by econeckt they have already said bracing will be free loan ,I like the number of different block types they do and the  size of them and thier locking lugs,downside is the concrete fill is 150mm and ISOTEX is 120mm -cost saving 

I do not have a site size problem so thickness of wall is not a problem  and i quite like ther idea of doing all the elec .plumbing etc chased into the walls ,then straight on with the plaster 

suppose it depends how sure you are of spec of house beofre you start to see if PB and service viod is an advantage or just more expense

I like the woodcrete cos no bracing required other than screwing some plywood on at corners and maybe a few other bits 

check ther ISOtex videos  -they build all walls and pot them and concrete roof in one go--you could not do that with poly --so to me that says its inherrently more stable 

I,m sure all systems work - 

Edited by scottishjohn

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On 02/05/2020 at 14:05, Russell griffiths said:

We are in Cirencester if you want to look at a Nudura icf house, blocks still visible inside and out, 

sorry to jump on the post. 
Can I ask why you used nudura? We’re looking at icf and nudura keeps coming up as the one to choose. 

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4 hours ago, Jvh2012 said:

sorry to jump on the post. 
Can I ask why you used nudura? We’re looking at icf and nudura keeps coming up as the one to choose. 

I went to visit lots of different build types and nudura just ticked the right boxes for me, you need to think about who’s building it and what their skil level is

then look at all the products and look for bits missing 

look at BECO WALL FORM 

then look at Nudura 

Add up all the pros and cons and work it out. 

You cannot get somebody on here telling you, you must use this system 

 

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