ICF timeline

[Reiver]

Following the advice of @Conor and @Russell griffiths on my curved wall insulation issue, I'm looking at ICF (I like the reinforcing aspect too) and I've spent 2 or 3 days looking at the different types. Given that this project would certainly be built in somewhere which is quite North and West and mountainous (=seriously crap weather) minimising build time to roof-on seems to be a good idea. So the question springs to mind as to how long you have to leave between pours to let the concrete set please? - does it have to be the normal 28-ish days to full strength?

Edited June 5, 2020 by Reiver

[willbish]

I've not heard of any minimum time between pours.

Considering how long it takes to strip all the bracing and supports (1 day at least), then build the next story (perhaps a week), finally adding bracing & supports (another day or a so), then confirming pump availability and concrete. I think there is no chance you could be pouring onto concrete that isn't cured even if you've got a large team of builders.

 

 

[ToughButterCup]

7 hours ago, Reiver said:

... how long you have to leave between pours to let the concrete set please? - does it have to be the normal 28-ish days to full strength?

There is no hard and fast minimum time between pours. I have personally heard more than a little bragging about complete houses done in one pour.  Complete expensive stupidity to even try.

 

The workflow is (often) build to first room height,  pour, continue building to second floor,  pour and so on. So the gap between pours equals the build time between first and second floors.

Concrete maximum strength occurs after a good few years.

 

[Russell griffiths]

@Reiver are you aware you can get curved blocks to suit your radius. 

[Vijay]

Also look at Polarwall for curved walls

[scottishjohn]

10 hours ago, Reiver said:

So the question springs to mind as to how long you have to leave between pours to let the concrete set please?

you can do your next pour as soon as the first one has set --better to do it sooner ,so it bonds to the first one -If you want to leave it long periods then make sure you use rebar and have them stcikingo ut into new pour and use a bonding ocat between layers -your ICF supplier will give you all this info .

look at this video -full house and roof poured in one go 

 

 there are plenty of other types but basic rule is up to ne storey in one pour if you want

 

Edited June 6, 2020 by scottishjohn

[PeterW]

You can pour when it’s hard - doesn’t need to be

cured and it’s the same with any concrete construction. Most if not all ICF has rebar in it for strength and it supports the joins between the pours - you will get a mechanical bridge between the pours even if you don’t get the full chemical join. The only issue is normally for basement walls with waterproof concrete that do need some sort of contiguous pour. 
 

The major reason for limiting pours is cost, as your concrete pump will be the big factor. I’ve seen a build where the guy got a towable Putz on hire for a month and basically he poured every couple of days as he did it himself. Very few issues and a very nice finished build and he did as much as 4 CuM of concrete would fill every time. I’ve also seen a big pour that had a huge 40m concrete pump that was like watching an angry elephant and it put me off using any sort of ICF..!! 

[Reiver]

Thanks for the input lads, it's good to know that work can continue without long waits.

Trevor

[Alexphd1]

I think willbish is pretty spot on, our 1st day after pour we just walked around with a grin on our faces. Couple of days to remove bracing before even thinking about building next course. 

Forget about bonding coat between pours unless waterproofing (you dont put a bonding agent between traditional concrete block wall?) 

Generally you pour one floor at a time but every build is different. 

Biggest recommendation is find someone building with ICF and be there on pump day. 

[Reiver]

3 hours ago, Russell griffiths said:

@Reiver are you aware you can get curved blocks to suit your radius. 

Yes, I've seen them in a couple of the systems. And the guy at Insulhub said that provided the numbers were big enough you can get Isotex blocks with chamfered ends to suit your radius.

[Reiver]

1 hour ago, scottishjohn said:

you can do your next pour as soon as the first one has set --better to do it sooner ,so it bonds to the first one -If you want to leave it long periods then make sure you use rebar and have them stcikingo ut into new pour and use a bonding ocat between layers -your ICF supplier will give you all this info .

look at this video -full house and roof poured in one go 

 

 there are plenty of other types but basic rule is up to ne storey in one pour if you want

 

Thanks for the video @scottishjohn - very informative and I love the almost complete absence of PPE ?

[Russell griffiths]

On 06/06/2020 at 11:04, Reiver said:

Yes, I've seen them in a couple of the systems. And the guy at Insulhub said that provided the numbers were big enough you can get Isotex blocks with chamfered ends to suit your radius.

So you end up with a hexagon wall instead of curved. ?‍♂️

[Reiver]

2 hours ago, Russell griffiths said:

So you end up with a hexagon wall instead of curved. ?‍♂️

Well not quite... using straight blocks it would be 22 sides for me (called an icosadigon says Wikipeadia - never got told that at school) or if you got them to do some suitably bent blocks 44 sides..... Certainly round enough for some olde-worlde render or stone facing to cover up I would have thought.

Edited June 10, 2020 by Reiver

[scottishjohn]

izodom2000 also supply curved sections ot your spec

[Reiver]

Aye, I've seen them. My leaning towards Isotex is for a couple of reasons:

 

a) because I think I'm unlikely to find an experienced Izodom or general poly-ICF installer in the area - and Isotex is more like doing ordinary blockwork, so I'm more likely to find some lads who can pick it up quickly???

b) the bracing requirements are a LOT less if you stick to their 6 courses per pour (you'd be a nutter not to), and as it's very likely the build would be on a slope (or  even on a bit of a rock end) I'm concerned about bracing the downslope side..... we might end up needing some very long props!

c) I like the reinforcement regime, and I like strong after being out in 90+mph back in the storm of 2005.

d) it looks to be better for fixing stuff into internally.

 

Or have I missed something???

[Russell griffiths]

Just remember if you pour every 6 courses that’s a lot of concrete pump hire. 

Our wall height is about 5.4m we poured this in two pours so 2 x £600 pump hire, if you pour every 6 courses that could get expensive. 

[Vijay]

5 minutes ago, Russell griffiths said:

Just remember if you pour every 6 courses that’s a lot of concrete pump hire. 

Our wall height is about 5.4m we poured this in two pours so 2 x £600 pump hire, if you pour every 6 courses that could get expensive. 

Exactly why I why told to stick to per floor pours too

 

[scottishjohn]

28 minutes ago, Reiver said:

Aye, I've seen them. My leaning towards Isotex is for a couple of reasons:

 

a) because I think I'm unlikely to find an experienced Izodom or general poly-ICF installer in the area - and Isotex is more like doing ordinary blockwork, so I'm more likely to find some lads who can pick it up quickly???

b) the bracing requirements are a LOT less if you stick to their 6 courses per pour (you'd be a nutter not to), and as it's very likely the build would be on a slope (or  even on a bit of a rock end) I'm concerned about bracing the downslope side..... we might end up needing some very long props!

c) I like the reinforcement regime, and I like strong after being out in 90+mph back in the storm of 2005.

d) it looks to be better for fixing stuff into internally.

 

Or have I missed something???

yep 

talk to isotex man --you can pour to first floor  in one go 

|I am guessing you looking at italian video 

 norebar needed for UK --no earth quakes

our blocks are different than thiers

-speak to insul hub UK

Edited June 11, 2020 by scottishjohn

[scottishjohn]

29 minutes ago, Reiver said:

because I think I'm unlikely to find an experienced Izodom o

uk agent is in glasgow and they also build-- so thats pretty local 

[scottishjohn]

On 06/06/2020 at 10:53, PeterW said:

40m concrete pump that was like watching an angry elephant and it put me off using any sort of ICF..!! 

most ICF makers tell you to get an "s" bend at the end of the pump line and at 100mm dia --to restrict the angry elephant  effect

the S"" bend is to slow down the muck coming down that very long boom and therefore cut down on hydraulic effect on the wall 

Edited June 11, 2020 by scottishjohn

[Mr Punter]

I think the small concrete pumps are more forgiving than the Schwing lorry pumps.  They are often run by smaller operators and the kit is cheaper.  It takes a while to set them up but they may be cheaper if you need a few pours and get on OK with the operator.  Not so fast and furious.

[Reiver]

1 hour ago, scottishjohn said:

uk agent is in glasgow and they also build-- so thats pretty local 

Certainly convenient location-wise (unless I end up getting pushed too far North!) but didn't someone on here say that their pricing was somewhat poisonous?

[Reiver]

2 hours ago, scottishjohn said:

yep 

talk to isotex man --you can pour to first floor  in one go 

|I am guessing you looking at italian video 

 norebar needed for UK --no earth quakes

our blocks are different than thiers

-speak to insul hub UK

If you'd said that a couple of days ago I'd have gurned a bit as the first couple of conversations I had with Insulhub weren't particularly rewarding ? . However a guy called Andy rang me back yesterday morning and seems a lot more clued up and helpful; I'll ask him about build heights tomorrow. I'm just rather thankful for and aware of Tougbuttercup's experience here:

The way the weather is round here these days, a serious storm seems to be able to appear out of nowhere pretty well any time of the year, and at most places out here on the North west coast you're looking at a design windspeed of >25m/sec. So maybe it will have to be a see how it goes at the time approach and be careful on the upper storeys. Certainly if it was possible to do even the lower bit in 2.4m ish pours it would save a fair bit of dosh.

And BTW we've had 2 small earthquakes here in the last 10 years ? - only 3.5 ish , but they made everyone in the village run outside wondering what had happened and broke a few bits of crockery on high shelves. I was in the pub when the last one struck and we thought a wagon had clipped the corner of the building.

Edited June 11, 2020 by Reiver

[scottishjohn]

49 minutes ago, Reiver said:

Certainly convenient location-wise (unless I end up getting pushed too far North!) but didn't someone on here say that their pricing was somewhat poisonous?

just speak to them -- he didn,t get anybody to do it --he did it himself --so maybe his idea of expensive  was tainted

[Reiver]

OK, I'll give them a bell and see if I can get some pricing. Meanwhile I've had a long crack with Andy at Insulhub this morning and you're right, they're happy with putting up 2.4m of Isotex at a time - at least up to a certain height, he thought it might be necessary to rein things back a bit if you start to get high and the weather's crap. He was also forthcoming on the reinforcing aspect: not really needed for a bungalow in a sheltered spot, but if you were building 3 storeys in an exposed position in the North West then some would likely be needed - even if it's not up to the Italian earthquake standard. Apparently they're also going to be doing a series of British videos soon which will be interesting to see.