Help me out of these holes, please!

[ToughButterCup]

Meanwhile, back at the ranch, we decided not to trust even one block laid by the original builders.

And that means treating the Durisol like, well, the wall at Blackpool sea front. I know, it's tantamount to an admission of defeat. But do we want a wall we can trust or not? Short of scanning each block for integrity (well nigh impossible) there's nowt else we can do.

 

 

Have a look at those lovely lengths of threaded bar fastening the OSB to a similar support structure the other side of the wall. My God I can cut and trim threaded bar to size at speed now.

 

And in doing so have presented myself with 60 cold bridges. Poo.

 

Here are two ideas that we have come up with to fettle the issue.

• A few hours after the pour, undo the nut on the outside (insulation side of the ICF) and tap the threaded bar back in (say) 60 mm, and fill with foam. Allow  the concrete to cure. Remove the sheeting, and drill back the bar from the inside this time. Fill with foam.
• Leave it. Allow to cure. Drill out 120 (both sides of 60 bars) to a depth of 60 mm, fill with foam

 

Has anyone got any bright ideas? Please? Hope so

Ian

 

 

[Jeremy Harris]

Grease the studding before fitting.  Pour the concrete.  Unscrew the studding from the concrete after it has partially (not fully) cured.  Fill the holes with slow expansion foam.

 

Make sure you remove the greased studding before the concrete has fully cured.  Concrete shrinks in the final stage of the cure, and will grip tightly around anything inside it.  This is why rebar ends up gripped very tightly inside cured concrete.  However, at the "green" stage, where the concrete is solid, but still weak, it hasn't yet started to shrink, so won't have gripped the studding tightly.

 

To get the studding out, either use a stud remover that tightens on the stud itself as you unscrew it, or just lock two nuts together and use the inner one to unscrew the studding.  If it were me, then I would sacrifice the ends of the studs and use one of these to unscrew them: http://www.halfords.com/workshop-tools/tools/hand-tools/laser-impact-stud-extractor-1-2-drive 

 

Don't get this one from Halfrauds though, there are much better made ones.  This was just a quick image I grabbed from a search to show the tool I mean.

 

Edited August 29, 2017 by JSHarris

[Stones]

Are you bracing the pour as per Durisol instructions? Do they have any recommendations?

[PeterW]

As JSH says - grease is your friend..

 

Quick way out with studs is undo the back side nut, clamp the inner end in the drill chuck and then put a spanner on the inner nut. It will spin the stud out against the timber. It's a poor mans version of a stud extractor but works ..!

 

back fill with either foam from both ends or get a mortar gun and make a 3:1 mix to plug the outer end and then foam from the inside. 

[Russell griffiths]

They do actually make a thing for this exact purpose,for shuttering carpenters, it is very much like a piece of 3/4 overflow pipe 

it is placed inside the shuttering and the threaded rod goes through it, leave threaded rod in until fully cured and then remove, you will be left with a very neat 3/4 Diameter hole you can then fill. 

[MikeSharp01]

+1 for grease and unscrew when green or alternatively use plastic studding such as THIS stuff then you can leave it in, it should be strong enough and although it may absorb water, nylon does IIRCC, only a tiny amount and then it will be stable.

[ToughButterCup]

You lot are brilliant. Thanks so very much indeed. I lost a good deal of sleep about this last night. I wish I'd posted this earlier................

Now, only got 60 studs to take out, grease and replace before we pour on Monday.

[ToughButterCup]

1 hour ago, Stones said:

Are you bracing the pour as per Durisol instructions? Do they have any recommendations?

 

They have no recommendations because shuttering is not normally needed. Normally.

[ToughButterCup]

1 hour ago, PeterW said:

[...]

Quick way out with studs is undo the back side nut, clamp the inner end in the drill chuck and then put a spanner on the inner nut. It will spin the stud out against the timber.

[...]

 

You seem to suggest you both clamp the inner nut (in a drill chuck) and put a spanner on the same nut.... or have I got the wrong end of the nut, as it were?

 

[PeterW]

Inner end of the stud ..... sorry ..!

[ToughButterCup]

1 hour ago, JSHarris said:

Grease the studding before fitting.  [...]

 

Quite a few of the bits of threaded bar are already in: I don't suppose I could use WD40 spray to the same effect could I? It would save a good few hours' work.

 

I'm thinking that simply removing one set of braces from one side would expose the threaded bar partially. And being able to spray a good size gobbit of WD40 along the bar would help a good deal. I'm on my own on site until they come to pour on Monday...... 

[PeterW]

Anything oily will do tbh - can you see from the top and use a plant sprayer and some veg oil ..?

[ToughButterCup]

Hmmm, probably not, but I have do have a very curious cat. I'll try and persuade him. 

 

I've just emailed the MD of Durisol to see what's what on this one.

[Russell griffiths]

Looking at your pic it all looks jolly strong, but do you have any provisions for making it plum. 

Even after the concrete is poured I would want a way of checking plum and the ability to adjust if necessary. 

[ToughButterCup]

2 minutes ago, Russell griffiths said:

[...] but do you have any provisions for making it plum. 

Even after the concrete is poured I would want a way of checking plum and the ability to adjust if necessary. 

 

 

Arghhhhhhhhhh. The wall was plumb before we shuttered it. But thanks for the nudge. I'll go and check the bits that we have already shuttered now. Like right now.

[ProDave]

Probably too late for my solution, but sleeve the studding e.g with pvc conduit, so the concrete never touches it. Withdraw the studs from the conduit once set and fill with foam. You will also then have a lifetimes supply of lengths of stud for "projects"

[Russell griffiths]

I am thinking of icf so have watched a lot of vids on it. I would want something ready for when you pour in case it goes out of plum, like some studs pre cut and a load of screws handy or a couple of acrow props. 

Unless you are 100% it ain't going nowhere. 

[Russell griffiths]

6 minutes ago, ProDave said:

Probably too late for my solution, but sleeve the studding e.g with pvc conduit, so the concrete never touches it. Withdraw the studs from the conduit once set and fill with foam. You will also then have a lifetimes supply of lengths of stud for "projects"

Already suggested that ?

[ToughButterCup]

Been out and had a closer look at everything. Piccies to follow soon. 

State visit from friends - and lunch - intervenes 

[CC45]

Farmers I've know use short lengths of water pipe around the threaded bar.  Leaving it in after the shuttering comes down.

[ToughButterCup]

Or some simple electrical conduit would do.... my head's fizzing 

[Onoff]

20mm pvc leccy conduit all day long. You can get heavy duty (thicker wall) stuff too btw.

 

(I proposed similar a while back I think for a home brew SIP shed. As in space OSB say 150mm apart and fill with foam).

 

Tut, tut, some of those square washers look pi $$ed! 

 

[ToughButterCup]

As you can see from the following pics:

 

There are three layers of reinforcement, each tied by threaded bar into a parallel set of timbers the other side of the wall

 

The top layer is easy to see  and so to get to thus;

 

 

Then, some of the threaded bar in the middle layer is exposed because it hasn't been tightened up  yet, so I stand a good chance of getting some silicone grease or vegetable oil or something like that to worm its way along the metal; ... a good squirt or two of whatever might well make its way along the bar...

 

 

And the bottom row of fastening points are driven through concrete that has already set for a month (the layer on which Mark is working in the top photo..... and so should be easy to withdraw, and squirt foam through.

 

Which leaves a fighting chance of being able to withdraw most of the bars.

 

@JSHarris,  How long can I leave the bars in before concrete grips too hard to withdraw the bar?

 

 

 

[Russell griffiths]

On a different note are you having any external insulation over the durisol blocks ?

if so then is this little cold spot really an issue. 

 

 

To completly think a bit differently why not leave them in until concrete is cured, remove timber, smash the granny out of the threaded stud smashing it through to the inside, use a drift to punch it 50 mm into the outside face, cut off flush inside, fill hole outside 

 

there i I bet that will get yer brain tingling. 

[ToughButterCup]

Hi @Russell griffiths: that was going to be my fall-back strategy.

There's no need to (normally) cover Durisol (u0.15)....