Expansion joints and firestops..

^woody^ said:
The silly thing though, is that some bricks/blocks will cause the wall to expand more than others, so the general guidance of joints every x metres is not always necessary
Click to expand...

Agreed, I've seen a wall crack 1m from a movement joint.

I feel though, that if you follow the regs at least it can be a defence if something goes wrong, as I found out the hard way.
 
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^woody^ said:
tawelfryn said:
...They want the wall to expand and contract, yet they specify, wall ties tying the two leaves, etcl:
Click to expand...

The wall will expand/contract along its length, and there is enough flexibility in the ties to accomodate this. The ties are intended to tie the walls together and prevent movement in the other direction.
Click to expand...

I hear what you are saying woody, and on these type of tie I would agree,
http://www.sigexpress.co.uk/Wall-Ties-and-Restraint-Fixings/Ancon-RT2-Wall-Ties.htm

But on these ties no way, these suckers dont budge an inch, and are more commonly being used, every brickies nightmare
http://www.sigexpress.co.uk/Wall-Ties-and-Restraint-Fixings/Ancon-ST1-Wall-Ties.htm
 
tawelfryn said:
I hear what you are saying woody, and on these type of tie I would agree,
http://www.sigexpress.co.uk/Wall-Ties-and-Restraint-Fixings/Ancon-RT2-Wall-Ties.htm

But on these ties no way, these suckers dont budge an inch, and are more commonly being used, every brickies nightmare
http://www.sigexpress.co.uk/Wall-Ties-and-Restraint-Fixings/Ancon-ST1-Wall-Ties.htm[/QUOTE]
Given that mortar is fairly soft (compared to brick/blockwork) and the movement takes place over several hours a few mm movement will be no problem.
Click to expand...
 
^woody^ said:
The silly thing though, is that some bricks/blocks will cause the wall to expand more than others, so the general guidance of joints every x metres is not always necessary
Click to expand...
Exactly Woody, which is why just slavishly following the Regs (whatever "they" may be) because they specify joints @ x metres, without a full appreciation for the application, environment and product is pretty pointless and a tadge ignorant. Event the manufacturers will specify distances for joints dependant on product type. E.g. Tarmac,

These distances are all obviously dependant on other factors being met.
 
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Slips ties should be used in movement joints, as these will accommodate movement.
 
hotrod said:
Exactly Woody, which is why just slavishly following the Regs (whatever "they" may be) because they specify joints @ x metres, without a full appreciation for the application, environment and product is pretty pointless and a tadge ignorant
Click to expand...

The regulations include the Building Regulations, British Standards and all the manufacturers literature I can see. I can't link to all of them as they are not freely available but if you need any let me know :p

BTW if you look at the full recommendations in the same document you posted the table from it repeats what I said earlier. But you know better, right ;)
 
So, am I correct in saying to build it to "Regs!" this wall would actually require 3 expansion joints.

3Mtr in from each corner and a 3rd one somewhere in the remaining 8Mtr.

Phoned BCO but he is on hols until Monday. View media item 10666
Elevation of the offending wall shown 3 expansion joints!!
 
I think checking with BCO is the best idea. See what they would be happy with and take it from there.

3.5m from either side leaves 7m in the middle which isn't far away.

The only thing I was trying, unsuccessfully it seems, to point out is that not following the manufacturers recommendations can be problematic.

Scenario: You build it as above. You then find a crack appearing due to expansion, nothing major but there just the same. So who do you complain to? Manufacturer isn't interested as you haven't followed their recommendations, BCO isn't interested as they don't guarantee workmanship although they issue completion certificate.

I agree all of this is this very unlikely but when asked the question I was only pointing out where the joints 'should' go.
 
Put one joint in where the gable meets with the horizontal section.

How materials are stored prior to building (kept dry) and how the wall is treated after building but before rendering (kept dryish, and avoiding any rapid temperature or moisture changes) will do more to determine how it expands/contracts.
 
Woody,

Apologies if I'm flogging a dead horse here but are you saying that the building regulations (there's that word again!) in this case don't need to be complied with? If so why comply with any of them?

It's not a trick question I'm just surprised by your advice.

Btw, free British Standards available for the doubters.
 
You are not referring the to building regulations - you are referring to the approved documents, which advise one way of meeting the building regulations.

I'm sure if need be, it would be possible to do some sort of calculation to prove that that wall, in that circumstance, with a particular build method, with a controlled mortar mix, would meet the the b/regs in terms of structural stability with no joints at all
 
Contrary to popular belief Building Regs are not cast in stone, they're more of a guide really and if deviating from them can be justified BC will usually be happy to allow it and again contrary to belief some BC inspectors do have common sense and do take that approach. If BC are happy with only one then what's the problem?
 
^woody^ said:
I'm sure if need be, it would be possible to do some sort of calculation to prove that that wall, in that circumstance, with a particular build method, with a controlled mortar mix, would meet the the b/regs in terms of structural stability with no joints at all
Click to expand...

Ah ok, so you calculated that OP only needed one movement joint using his build methods.

Sorry, I correctly interpreted the BS and referred to the manufacturers recommendations (all that I could find) but I'm obviously out of my depth here.
 
No you're not out of your depth, but you do need to lighten up and not be so defensive. It's a forum, there will be different view points, all of which may be equally valid.

I would swear by standards and regulations when I was 18, but then after a while experience kicks in

And read my post properly "It would be possible" does not mean "I have calculated" does it?

And this will be my last diplomatic post on this :evil:
 
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