Wall Ties spacing question

[GuineaPig73]

First post here, thought i would start with a picture too.
I'm going to fix some neoprene wall ties to my terraced house, but i'm not exactly sure of the spacing.

I've read somewhere else that every 5 bricks vertically from floor to roof should be sufficient, as you can see from the amateur graphics in the pic, i'm not sure if all it needs is one column running either side of the window, or 2 adjacent columns either side of the window.

Plus will i need some running over the top of the upstairs window ? Say 2 or 3 going horizontally across ?

Any thoughts/advice would be appreciated (also anybody who can sell me less than a box of 250 easyfix stainless steel wall ties would also be appreciated)

View media item 546

 

[noseall]

I'm going to fix some neoprene wall ties to my terraced house.

why?

 

[^woody^]

Did the Victorians build cavity walls?

 

[bean73]

there is a british standard for wall tie replacment which from memory is 450mm by 900mm spacing and then every 300mm around openings

hope that helps

 

[Shytalkz]

What has led you to think of doing this? Delamination of the internal part of the wall from the outer facings?

 

[GuineaPig73]

What has led you to think of doing this? Delamination of the internal part of the wall from the outer facings?

Thats a very good question !
Had a new digital aerial fitted and the fitter noticed the brickwork appeared to be peeling away around the upstairs window - had a builder have a look and he recommended neoprene wall ties.
The next door neighbours house has exactly the same problem, although they've had theirs done already at some point in the past.

In answer to Woody, no idea, honestly !
Basically i'm going off what this builder has recommended - here is another pic slightly closer up, you might just be able to see the gap thats opened up around the window. View media item 554

 

[Shytalkz]

Yep. can see from that pic.

The reason that this happens is that when the 9" solid walls were built, they often used cheap bricks to the inside half and facings to the outside. The brick bond (English bond: alternate headers and stretchers) is supposed to use headers that tie across the two halves; however, to save on facings, "snapped" headers were used, which gave the appearance externally of bonding across, but in reality, very few in the wall were actually full headers across the width of the wall.

Over time, when some slight foundation rotation occurs, or with wind suction, or lack of a mechanical tie at the first floor level, or a combination of any or all of these, the outer half separates from the inner, most obviously noted by gaps around structural openings.

It is commonly found in Victorian properties such as your terraced one.

So, yes, installing ties between the two halves is a good idea. But it is quite expensive: those ties are quite specialised and there are many variations on the market and many specialist installers.

Standard centres of 900 horizontal, 450 vertical and 225-300 around openings should suffice, but centres may need closing up in areas of wall where the bulging is more pronounced. It's up to you as to whether or not you just deal with the obvious areas, or whether you carry out a regime to the whole elevation. The latter would obviously be a better solution.

 

[GuineaPig73]

Shytalkz, Sir i doff my cap to you.

Interesting stuff, i take it i can read 'centres' as 'spacing' inbetween the ties ?
So 900mm horizontally and 450mm vertically, reducing down to 225-300mm around the windows will mean quite a few more wall ties are required than first thought . Ah well i'd rather overdo it than leave it undercooked so to speak.

Thanks to all once again.

 

[^woody^]

Drilling and fixing helical ties with epoxy is going to be a better, more cost effective and less intrusive solution