JUB ICF block system - first build experience

[Simon R]

We've just finished the ICF work using the JUB block system. This post is to let others know how we got on with the system and hopefully help when comparing the various block systems.

Before getting into the detail, we selected the JUB block as it was the only ICF system we found that does not require cutting on site. The house plans get optimised for the block which can mean the structure dimensions change by up to 75mm. At planning submission time we didn't know which building system we would use, yet alone the ICF block type. Ideally you would select the block type and then design to minimise cutting. As a result our block plan was more complex than it needed to be.

Pro's

• Accuracy of build. As it's a kit manufactured at the factory the blocks are cnc'd to the precise dimensions required. All cuts are square and smooth. We have found that the pour process does result in block movement, for example some of our window opening are approximately 10mm wider than they should be. Over a 3M window it's an acceptable level of accuracy and I doubt it would be better with any other block system. More attention to detail when bracing and shuttering would almost certainly reduce the movement.

• Less mess on site. Not having to cut blocks has a positive effect on the site mess. It does mean that you have to be very careful with the blocks as if you break it you may have to order another. JUB provided us with a set of spare blocks to help with just this kind of problem. We didn't need them to recover from damage, but we did use some to make up a lintel that was not on our original block plan.

• Little use of foam. The blocks key into each other meaning that very little foam gets used. For a real self build where you are putting the blocks together yourself it would be a blessing as the foam gets everywhere and ruins clothing.

• Clean openings. All the window and door openings are fully enclosed by the ICF.

• Fitting out. The blocks have a strong nylon webbing at 75mm intervals that allows battens to be firmly screwed to the ICF without having to drill into the concrete core.

 

Con's

• Locating the correct block. With so many blocks involved in our build it can take a while to locate the special block you are after. The blocks come on pallets, each with their own manifest so in theory it should just be a case of locating the block on the a manifest, going to that pallet and retrieving the block. But life's not like that the block you want will be buried at the bottom of the pallet. On a small site this can be quite a problem. It does improves with every block you use and in practice takes a lot less time than cutting blocks.

• Inflexible once you're on site. The kit approach means it's much more difficult to change details, you can't just change windows dimensions or move doors at will.

• Delivery to site. JUB will only ship on pallets so you need to have a means of offloading the lorry when it gets to site.

From our experience with the JUB system, we would certainly use it again. It may involve a lot more up front work in the planning stage but that pays dividends on site. We only built one gable ourselves but based on that it's a good system for the self builder as it's a straight forward assembly. In an ideal world we would have preferred to build the blocks ourselves and hire in help for the pours. From the point of view of minimising risk, having the structure done by and experience ICF builder was probably the smart thing to do.

 

646-2018 WALL - Assembly plan 1of2 A1.pdf

646-2018 WALL - Assembly plan 2of2 A2.pdf

646-2018 WALL - Cut elements - First floor.pdf

646-2018 WALL - Cut elements - Ground floor.pdf

646-2018 WALL - Bracing plan A2.pdf

 

Edited April 30, 2019 by Simon R
add window closure detail

[ToughButterCup]

44 minutes ago, Simon R said:

[...]

we selected the JUB block as it was the only ICF system we found that does not require cutting on site.

[...]

 

Bliss, sheer bliss.

Would have saved me thousands, and about a year. Ya live and learn, eh?

[Simon R]

14 minutes ago, AnonymousBosch said:

 

Bliss, sheer bliss.

Would have saved me thousands, and about a year. Ya live and learn, eh?

ah, more by luck than judgement I fear. I've just read WillBish's tale of woe with Logix and can't help feeling we just got lucky.

Simon

[scottishjohn]

13 hours ago, Simon R said:

the pour process does result in block movement

I always wondered it it would not be worth sticking them in places  as well with some low foam or thinset adhesive  /tile cement/ no nails  as you go  ?

 

Edited April 29, 2019 by scottishjohn

[Simon R]

10 hours ago, scottishjohn said:

I always wondered it it would not be worth sticking them in places  as well with some low foam or thinset adhesive  /tile cement/ no nails  as you go  ?

It's a good question. JUB our block manufacturers don't recommend glueing. The blocks have strong nylon webbing so it would be relatively easy to have put battens to tie sets of blocks together to minimise lateral movement. Movement in pillars would be a little more difficult to manage. The walls are quite flexible before the concrete is added and it's only once they have concrete that the bracing is adjusted to make the walls true. Our builders ICF-homes have a lot of experience, so we left it to them.

 

[scottishjohn]

1 minute ago, Simon R said:

It's a good question. JUB our block manufacturers don't recommend glueing. The blocks have strong nylon webbing so it would be relatively easy to have put battens to tie sets of blocks together to minimise lateral movement. Movement in pillars would be a little more difficult to manage. The walls are quite flexible before the concrete is added and it's only once they have concrete that the bracing is adjusted to make the walls true. Our builders ICF-homes have a lot of experience, so we left it to them.

 

don,t mention it or distinctly do not recommend.

and yes you would  still need bracing  for vertical ,but if partially glued would stop them moving about and making gaps 

different 

[Simon R]

Just now, scottishjohn said:

don,t mention it or distinctly do not recommend.

Good point, they don't mention it, rather than say you should not!

[janelondon]

Hi @Simon R thanks for this summary. Very interesting. We have a basement wing to our build and I'm strongly considering ICF. Would you mind PM-ing me details of your JUB UK contact? 

[Simon R]

20 minutes ago, janelondon said:

Hi @Simon R thanks for this summary. Very interesting. We have a basement wing to our build and I'm strongly considering ICF. Would you mind PM-ing me details of your JUB UK contact? 

Gary Peacey - gary@jub.org.uk  is the UK ICF man

[janelondon]

3 hours ago, Simon R said:

Gary Peacey - gary@jub.org.uk  is the UK ICF man

Thanks! How was the design process with JUB and general support during the build? 

 

[ToughButterCup]

On 28/04/2019 at 19:05, Simon R said:

We've just finished the ICF work using the JUB block system. [...]

 

I'm nosey.

Simon, could you post a picture of a corner and a window head / cill , and a normal run please?

[Simon R]

7 hours ago, janelondon said:

How was the design process with JUB and general support during the build? 

Very little support form the UK as all the technical knowledge is in the factory in Slovenia. We dealt directly with the technical team who could not have given better service. They were very proactive and quick to answer our questions. We supplied them with our plans from planning approval. JUB then produced a block plan, at the same time we had our structural calculations done. This was a bit of an iterative process as some practical implementation issues resulted in changes to the house design. As an example our planning drawings had some windows running directly into the roof with no lintels. If we were going to do it again the one thing we would do is start with the JUB ICF design guide, this would give you the opportunity to reduce the complexity of the block plan. In particular to avoid the 75mm blocks as they break the brick internal webbing pattern.

Ours is the first build in the UK using their block system so I can't guarantee that it would be the same for all customers.

 

[Simon R]

11 hours ago, AnonymousBosch said:

could you post a picture of a corner and a window head / cill ,

A couple of photos added as requested. It's a really clean solution, hopefully won't cause any problems when it comes to putting the windows in.

 

[ToughButterCup]

Erm...... Photos ?

[janelondon]

 

 

 

10 hours ago, Simon R said:

If we were going to do it again the one thing we would do is start with the JUB ICF design guide, this would give you the opportunity to reduce the complexity of the block plan. In particular to avoid the 75mm blocks as they break the brick internal webbing pattern.

 

Really helpful, thanks!

[PeterW]

3 hours ago, AnonymousBosch said:

Erm...... Photos ?

 

In the original post ... 

[Nelliekins]

One question - are the blocks sized off of metric or imperial measures? In particular, the spacing of the webs in my Logix build has been a complete ache of the dangles. You end up either using grab adhesive at the edge of plasterboards or having stacks of 185mm rips taken off your boards because the plasterboard is 1200mm wide and the Web spacings are 8" (203mm). Blooming annoying, especially since you can't just stick plasterboard offcuts in general rubbish! ?

[Big Neil]

I reaaalllllyyy like how everything arrives to a plan. It's the closest i've noticed so far to the 'it's just like lego' description i first heard of ICF. The only way I can really see that system being better is bespoke panel sizing or a wider range of block sizes to minimize time on site further. I watched an interesting video by fox blocks a while ago, about panelising the build off site. I guess that would be an interesting product to receives from a contractor - provide yor plans and name your blocks and then just recveive a panel plan to assemble on site.

[Randomusername]

I’ve been researching various ICF systems for my build/s. 
 

JUB looks interesting but as far as I understand they do a set of pre-configured designs, due to the nature of the construction meaning that blocks are all formed as the finished piece and do not require cutting. 
 

However I’ve searched in vain for an overview of these designs, in vain. Does anyone have any pointers? I’d like to know in advance whether any of them will be suitable for the plots dimensions/scale/outline planning/dimensions etc. 
Many thanks for any help. 

[Madasahatter]

Uniblock do a pre-cut system.  If you submit pre-planning drawings of your proposed building they will come up with of 'cost effective' means of constructing it. with their systems, so maybe some slight adjustments to design to reduce wastage and cutting.

 

The blocks are all cut and numbered at their factory, so no waste!  All you have to do is put them together - what could go wrong?  I've not used the company but it would appear to simplify construction, but I'm guessing at a premium - which may well be worth paying.

[Randomusername]

On 18/08/2022 at 13:00, Madasahatter said:

Uniblock do a pre-cut system.  If you submit pre-planning drawings of your proposed building they will come up with of 'cost effective' means of constructing it. with their systems, so maybe some slight adjustments to design to reduce wastage and cutting.

 

The blocks are all cut and numbered at their factory, so no waste!  All you have to do is put them together - what could go wrong?  I've not used the company but it would appear to simplify construction, but I'm guessing at a premium - which may well be worth paying.

That’s good to know thanks. 
Uniblock are on my list of preferred systems at this point simply because they’re U.K. manufactured, and I really don’t want the guilt of importing a massive bulk of insulation product 100s of miles, if at all possible!