COncrete Setting

[Big Neil]

theoretically how long would it take to build a normal 4 story house (just the icf part) up to roof height, lets say something around 220 - 250 m2 wall space, using an 'average' icf system, if one includes concrete setting time - lets assume you have an experienced crew of lets say 5 people. Also assume that you can carry on stacking after the first pour before the concrete is fully set.

[Big Neil]

no rain or adverse wind etc etc

[Conor]

Builders I've spoken to have said 6-8 weeks from founds to wallplate, so about 3 months to roof being on from breaking ground, then another 3 for full completion.

[jamiehamy]

How will you brace the walls above ground level? What is the floor makeup for each storey? Can you coordinate install of floor with the concrete pours? Are the floors concrete or timber? How much rebar is required? How many openings? How many corners? How are you pouring? How experienced are the pump crews, concrete drivers and block builders? A 'crew'is all the parts and just saying' a competent crew' is far too general. How long will it take to erect the scaffolding as you go up? How do you ensure no adverse weather? (which is a fact of life and no value in ignoring because one spell of wind, severe rain or other can stop everything else. What system are you using? How do you counter illness or other human factors? Until you provide realistic answers to at least the above, then no estimate is of any use. Answer all of the above and you'll get somewhere near the truth. Otherwise, perfect everything - 2 months. Just a guess! 

 

However, you say '. Also assume that you can carry on stacking after the first pour before the concrete is fully set.' 

 

Which suggests you think 12hours time saving is worthwhile in the course of building a house. You're thinking about this the wrong way if recommencing block work before the concrete has gone off is a factor in your time savings. Sorry, no point sugar coating it. If building a house to a strict timetable is the plan, you're setting up to fail. If you add more context as above, maybe we could give a better idea of timescales ? 

 

 

[scottishjohn]

28days is what they normally reckon for concrete to get to most of its hardness,then its to full strength in about 20-30 years 

[ToughButterCup]

2 hours ago, Big Neil said:

theoretically how long would it take to build a normal 4 story house (just the icf part) up to roof height,[...]

 

I have heard an ICF rep claim to have poured two storeys per pour. Hmmm, but there's no reason that the four storey shouldn't be poured in four pours - just possibly 3.

How well are you prepared? 5 experienced crew? And a pump operator who knows his stuff ... 

 

Knowing what I now know, I'd shoot for getting it done in Durisol  in a week. But I'd be all over every joint , every detail, every window, every door head  and be a right royal pain in the  arse for the crew. 

 

But most of all I'd insist  on a super tidy site with all trip hazards minimised

[Big Neil]

7 minutes ago, AnonymousBosch said:

 

But most of all I'd insist  on a super tidy site with all trip hazards minimised

This is the sort of thing i had coming to mind. Ruthless efficiency etc.

 

2 hours ago, jamiehamy said:

 

Which suggests you think 12hours time saving is worthwhile in the course of building a house

 

why shouldn't it be? I posted actually because i got to thinking of that grand designs years ago were the huf-haus went from foundations to being ready to move in, in about 4 days. It's not a topic that is really discussed in particular depth much, just in anecdotal fashion

2 hours ago, jamiehamy said:

How do you ensure no adverse weather? (which is a fact of life and no value in ignoring because one spell of wind, severe rain or other can stop everything else

 

i didn't say it can be ensured  or to ignore it, but why not consider measures to mitigate the effects. Tent the lot for example. OK maybe not cheap, but a possible option. BUt in either case its not about giving context, it's about fag packet ideas and brainstorming. Say 5 years if you like, but justify it. Asking to discount some factors is simply a method to establish a baseline. Thin  joint for example you can apparently lay down to zero degrees, so using this might be a way to mitigate cold in a cavity wall build. EPS is water resistant so building icf is a way to mitigate at least some of the rain factors

 

2 hours ago, Conor said:

Builders I've spoken to have said 6-8 weeks from founds to wallplate, so about 3 months to roof being on from breaking ground

INteresting - see that ties in almost perfectly with @scottishjohn figure of 28 days, so break ground and construct foundations including pour - leave to set for up to 28 days - start constructing first rise during this time then pour on day 28 - and so on.

 

I suppose if you left it long enough after the first poor, and were using ICF internal walls also, you could do some of the chasing for the electrical bits/plumbing during that time??

[Big Neil]

and have just noticed i said 4 storey where i meant 4 bed and 2 storey - 

[Alexphd1]

Big concrete pours are scary, our highest was approx 4.5m (inc gables) and i don't think i would do it again. It gets difficult around windows on the floor below. A lot of bracing is needed! even working the poker is bigger job! TBH First 24 hours after pour for us was very unproductive..... i was just walking around in a daze with a big smile!  I think you can starting building the next icf course pretty quick after the pour but I would hold of a while before pouring the concrete, that's where the weight is!

 

A stupid idea if you where doing two floors per pours i would consider not cutting out windows and doors and cut them out after concrete has cured (be careful this idea prob creates more problems than it helps!)???

 

 

Edited May 14, 2019 by Alexphd1

[PeterW]

1 hour ago, Big Neil said:

so break ground and construct foundations including pour - leave to set for up to 28 days - start constructing first rise during this time then pour on day 28 - and so on.

 

Eh...?? 

 

Dug Founds Tuesday, poured Thursday, marked out Friday, first course blocks following Monday .... 

 

There is a big difference between set and cured with concrete. 

[scottishjohn]

2 hours ago, Alexphd1 said:

Big concrete pours are scary, our highest was approx 4.5m (inc gables) and i don't think i would do it again. It gets difficult around windows on the floor below. A lot of bracing is needed! even working the poker is bigger job! TBH First 24 hours after pour for us was very unproductive..... i was just walking around in a daze with a big smile!  I think you can starting building the next icf course pretty quick after the pour but I would hold of a while before pouring the concrete, that's where the weight is!

 

A stupid idea if you where doing two floors per pours i would consider not cutting out windows and doors and cut them out after concrete has cured (be careful this idea prob creates more problems than it helps!)???

 

 

that could work if you put in the rebar where the lintels would be and  around where the door frames would be ,but would be waste of concrete and icf forms +you would not have insulation all around the concrete after you cut the holes .

just make very stong "bucks " as the yanks call them --linings to all openings in wood and cross braced,

most SE,s will want some rebar around big load areas to spread the load around the "holes" and to stop possible cracks 

"seems like a long for a short cut"

 

Edited May 14, 2019 by scottishjohn

[Alexphd1]

Yeah John creates more problems than solves! 

[Russell griffiths]

11 hours ago, Big Neil said:

and have just noticed i said 4 storey where i meant 4 bed and 2 storey - 

 

You plonker Rodney ??

 

so 7-10 days to get up to 2.7 high

1 day to pour

7 days to do nothing

5-7 days to put first floor in

7-15 days to build up second floor including gables

1 day to pour 

7 days to do nothing

3 days to remove props, strip out window bracing, de nail and clean everything 

so that’s my take on it. 

 

Lots of variables though

how big are your openings, we have some reinforcement cages over some windows that consists of 6m long bars with links every 150mm, those took a stupid amount of time to tie up, probably half a day for one cage. 

So it really depends if your house is a square box with small windows

square box with small windows consists of 4 external corners and just straight bars above openings, very little bracing needed. 

A complicated house with large openings could add another couple of weeks to that schedule. 

Edited May 15, 2019 by Russell griffiths

[Big Neil]

9 minutes ago, Russell griffiths said:

You plonker Rodney ??

so 7-10 days to get up to 2.7 high

1 day to pour

7 days to do nothing

5-7 days to put first floor in

7-15 days to build up second floor including gables

1 day to pour 

7 days to do nothing

3 days to remove props, strip out window bracing, de nail and clean everything 

so that’s my take on it. 

 

 

Well done that man - exactly the sort of thing i was thinking

 

10 hours ago, PeterW said:

There is a big difference between set and cured with concrete. 

 

Right you are - OS I'll take 'SET' to be full design strength. 'CURED' is clearly part way there. I assume enough of a way to walk on etc?

[PeterW]

18 minutes ago, Big Neil said:

Right you are - OS I'll take 'SET' to be full design strength. 'CURED' is clearly part way there. I assume enough of a way to walk on etc?

 

Wrong way round .... set is when it’s hard enough to walk on etc, cured is its 28 day strength reached. 

[Big Neil]

gotcha.