Extracting recalcitrant threaded bar from Durisol

[ToughButterCup]

Back in this thread, I explained how we were going about remedial works to cope with the likelihood of further poor workmanship of our original installer .

 

The strategy relied on  installing shuttering: that in turn needed to be tied in with threaded bar. Since that threaded bar was going to be immersed in concrete, those bars needed to be extracted a bit sharpish. Of the 140 odd we installed, a few stuck fast.

Today the steep learning curve on how to extract those that remained.

 

The idea was to core from the inside (concrete) from inside - outwards and then just pull the rest of the bar out of the PIR.

 

At first, using a 25mm core, like this

 

 

I found that I fouled the threaded barrel by drilling slightly off center.

 

So, back to the 38mm core and bingo

 

What did I learn?

• Don't use a diamond core bit on hammer. You knock the teeth off the core bit. 
• Shutter Durisol no matter what they say on their website. It ain't wurf it, mate, ain't wurf it. ( @jamiehamy, sit back and smile )

 

Sharp lessons in self-build: at least one or two sharp lessons a week at the current rate. 

[jamiehamy]

Smiling with you -  with you! The penny will drop soon - just don't tell Debbie - Once you've done it once by hook or by crook, a sneaky urge to do it all a again quicker, cheaper and better sets in. You only get good any any part of it just as you finish that part! Both of us are agreed we'd like to do another one some day now we know how to actually do it! 

[Jeremy Harris]

@recoveringacademic,

 

Given that you've been at the (very) sharp end of the learning curve with Durisol, apart from the great help that's been to anyone reading this forum, do you think there's any chance of your experience being incorporated into the procedures that they teach?

 

From what I can gather, Durisol have been pretty reasonable in dealing with your problems, that seem to have been mainly poor installer practice, not a failing of their system, or a failing by you (few self-builders would go so far as to attend a manufacturer's training session as I think you did).

 

It seems there would be a big benefit to them in making the need for propping in some circumstances (i.e. when a wall isn't going to be filled immediately) a part of their standard instructions.

Edited March 6, 2018 by JSHarris
misleading term used - thanks @jamiehamy

[jamiehamy]

If I may, can I suggest we discuss terms, three in particular that I think are distinct and not interchangeable? 

 

Bracing (in ICF context) - a method of supporting a wall prior to concrete being poured. Main aim is to offer horizontal  support to the wall before and during pour, especially advantageous to long sections, but also can be used to ensure wall is plumb - both during Co structure and during pour. Does not offer any shuttering effect. 

 

Shuttering - creation of formwork, mainly using sheet timber or metal formwork to create a form(shape)  into which concrete is poured. Shuttering can be used to create foundations, walls, steps or other shapes. Once concrete has gone off, this shuttering is removed. In ICF terms, generally the blocks are the shutter themselves and remain in situ as the insulation. Whilst the icf block work is a shutter, it can be prudent to add additional shuttering at vulnerable sections or as a 'belt and braces' approach. 

 

Propping - offering direct support to prevent movement, often a vertical prop for lintels or roof/ceilings but can be used horizontally to support shuttering. If used horizontally, offers similar support as bracing. 

 

Thoughts?  

 

 

[Jeremy Harris]

@jamiehamy, thanks, that's a good point, my language above was sloppy, I think what I meant was propping, so I'll edit the post to make that clear.

[jamiehamy]

Just now, JSHarris said:

@jamiehamy, thanks, that's a good point, my language above was sloppy, I think what I meant was propping, so I'll edit the post to make that clear.

It's okay, wasn't aimed at anyone in particular, it's just that in various threads I've noticed terms being used in a way I wouldn't - doesn't mean it's wrong, but might help us all! J

[bassanclan]

What would happen if the threaded bar was not removed and simply cut flush with the surfacw of the wall?

[jamiehamy]

Theoretically it could corrode over time and cause the concrete to crack or spall. 

[ToughButterCup]

35 minutes ago, bassanclan said:

What would happen if the threaded bar was not removed and simply cut flush with the surfacw of the wall?

 

Nowt.

Except interstitial condensation, mould, gnashing of teeth, foaming at the mouth, hair and teeth flying in all directions. And anyone and everyone on this forum who is in the slightest interested in passivhaus shaking their head saying

 

"Has he learned nothing?"

 

[ToughButterCup]

1 hour ago, JSHarris said:

@recoveringacademic,

Given that you've been at the (very) sharp end of the learning curve with Durisol, apart from the great help that's been to anyone reading this forum, do you think there's any chance of your experience being incorporated into the procedures that they teach?

[...]

 

Durisol North are visiting (again) tomorrow; we discussed the issue of creating online T+L materials last summer. Who knows what will come of it?  Lord knows, I have enough source material to put together a course on ;  

 

How to screw up a Durisol Build In One Easy 10 week Course, (while maintaining a sense of humour) and (now I come to think about it)

How to Cope with the Consequences of a Screwed Up  Durisol Build (in 20 hard lessons. Lesson 1: don't use a core drill bit on hammer - the teeth fall off)

 

There's a new build in Durisol in Lancaster starting this week.  Bet they know about diamond core drill bits.

 

Can't take a joke? Shouldn'a started should I?

[Onoff]

@recoveringacademic, what size threaded bar is that?

 

Thinking that with a die nut:

 

 

And a box spanner, you could re thread the damaged end. Then screw on a studding extension:

 

 

Add a bit of studding,  drill a hole in a spreader timber and have another go at winding it out.

 

Edit: Have I read this wrong? The studs are already out?

Edited March 6, 2018 by Onoff

[ToughButterCup]

1 hour ago, Onoff said:

@recoveringacademic, what size threaded bar is that?

Thinking that with a die nut:

And a box spanner, you could re thread the damaged end. Then screw on a studding extension:

Add a bit of studding,  drill a hole in a spreader timber and have another go at winding it out.

 

I really appreciate it when members think with me.

We tried that, @Onoff, and it worked - to an extent. We also tried three other ways. Sometimes it didn't work with any method, and we had to get on with other stuff. Now we face the challenge of extracting threaded bar from fully cured concrete by a self-build enthusiast who has never before

•  used a core drill
•  made a safe working platform at that height out of kwikstage (and appropriate fall prevention precautions)
• tends not to read instructions

How hard can it be with that mix of online readers and a just-bloody-do-it  approach? 

 

Just for the record, I went to Screwy's and told them about my Erbauer core drill set. At their suggestion, they replaced the whole set , no quibble, and in addition gave me a £5:00 credit. So I bought a scaffolder's magnetic level as well. I know SF come in for some stick, but replacing a complete set of core drills without even the beginnings of a quibble is first class. Well done ScrewFix.