What is it?

[Dave]

Found this in the garden, looks like something used to key 2 bricks together, but why is there a twist in the middle?

[michael adams]

Its a vertical twist tie used to tie cavity and external walls.

They're laid on a slight slope. The twist is so that any water or built up moisture or condensation drips off the twist in the middle of the tie rather than running down to the end and soaking the cavity wall.

michael adams

[mick]

It's a wall tie. The twist is so that any condensation or moisture leakage drips down the centre of the cavity rather than reaching the interior wall.

[The Natural Philosopher]

It is indeed a brick tie. goes across a cavity IIRC.

Never did understand why the twist.

[Dave]

The previous posts explain the twist.

Thanks for all the replies.

Dave

[Phil L]

The twist is so that whichever way up it gets put in, there's a low point in the centre for moisture to drip off. Prior to this, they had just a 'bump', and they were supposed to be laid with the bottom of the bump at the underside, but dozy bricklayers often put them in with the bump at the top.

The one in the picture is called a fishtail brick tie, these rust terribly and push courses apart, usually every 6 courses and often near the upper parts of the building. Once they start going, they need isolating and new replacement ties going in, they are isolated by chipping all around each one (found by metal detector) and a plastic sleeve containing grease is slid over the end of each one to prevent further corrosion, new ties are put through the face of the brick rather than the beds.

Galvanised ones were used after this but they too were shunned in favour of stainless steel and even plastic ones, which had a short lived popularity in the early 90's.

[Dave]

The things you learn on this group!

Dave

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember [e-mail] (Dave) saying something like:

[Andy Champ]

It's the galvanised ones I grew up with. Are _any_ of them good long term?

Andy

[The Natural Philosopher]

Houses in the 50s were built with em, Houses in the 50s still standing :-)

[Tim Streater]

Yerrss. Our house was built 30s, when we had DG recently I checked them far as I could see into the cavity as each old winder was took out, they all seemed in good nick, orright?

[Andrew Gabriel]

The damage happens to the part embedded in the outside wall. If that starts rusting, it swells and can push the bricks apart at the mortar lines with great force.

[Phil L]

They all do exactly what they are supposed to do, and that is to tie the two skins of brickwork together, or to keep them apart, whichever way you want to look at it.

The only problems with any of them are sulphur attack, IE rusting and forcing the brickwork apart. Stainless ones will never do this and so they are obviously the best ties to use. Galvanised ones are the next best, but these were laid to rest by someone sitting in an office somewhere who had nothing better to do than have idiotic brainwaves....the story goes along these lines; the bricklayers often rattle down the ties with their trowel, and this could chip off the zinc, leaving the ties unprotected and so they were banned. IME I've only ever seen brickies hit the ties in the centre, IE above the twist and so if any damage did occur, it wouldn't be near any mortar beds it would be in the centre of the cavity, and even then in only about 1% of the ties. I have them in my house, as do all the other properties around here, they are all 50 - 60 years old and none of them have shown any signs of failure or sulphur attack

[Phil L]

Yep and they probably will be for another 100 years or so. Galvanised ones aren't sold anymore AFAIK due to them not meeting building regs, although there are probably several hundred million still knocking about in people's sheds etc. Stainless ones are fairly cheap nowadays anyway

[Bob Minchin]

The ties in my house built in 1925 are starting to fail. Main problem is that the tails are swelling with rust and forcing the bricks apart. The problem is exacerbated by high porosity handmade bricks. Lime mortar was used in those days so the wall will have to be rebuilt in the next few years. I've no idea if they are galvanised or plain steel from that era. Still 85 years is not too bad!

Bob

[Jim]

We had a similar problem with our 1927 house - porous bricks, lime mortar and ties which appear to have been galvanised originally but which were rusting to bits.

We had a company install stainless wall ties over all the external walls by drilling through the bricks, they then dug out the lime mortar around the ends of the ties and put a sheath around them, repointing as necessary.

Cost in the region of 4 grand.

[The Natural Philosopher]

No. walls are designed mainly to not get soaking wet.

[Bob Eager]

I was always told that the whole point of galvanising was that it didn't actually matter if the coating wasn't continuous.

[Phil L]

And this job would have made a perfect DIY project and saved you thousands.

You can buy all the materials you need online or from BM's and hire metal detector, SDS drill and thin chisel bit. One man could do an average semi in a week and total cost of materials, tool hire etc

[Phil L]

? ? ?

A combination of wind and rain will see all walls get soaking wet from time to time, regardless of which way they're facing.