Wall Tie Worries

[Andy]

Folks,

I am building a block boundary wall, and need to tie into brick pillars. For the preexisting brick pillars I bought a galvanised wall tie system from screwfix

website says internal/external use. The piece of paper in the placcy bag it came in says 'internal use'. Any ideas on which is right and why?

Also, for those brick pillars I am building I bought some Wickes SS butterfly wall ties, usually associated with cavity walls: are these OK for tying blockwork to brickwork in the case of a wall to a pillar?

Any thoughts welcome,

Andy.

[Grunff]

Although it's galvanised, it will eventually start rusting if used in an outdoor wall. This will cause rust stains on the wall.

Ideally, you should use a stainless one,

Yes, they're fine.

[Lobster]

in its listings so I'd always certainly trust the packaging over what the website says.

Their returns policy is very good and I'm sure they'll swap them without charging P&P if you explain the situation.

David

[Lobster]

Actually I've just looked at the site - notice the 'blurb' for both stainless and galvanised ties is identical, on both listings it says "internal and external use; available in galvanised and stainless".

Which is a bit crap really!

David

[Andrew Gabriel]

AFAIK, use of galvanised wall ties on external walls was banned sometime last year, because the galvanising was too often damaged on building sites or during installation. Ties have to be stainless steel now.

[Andy]

Thanks Folks,

A 'phone call to Screwfix is on the cards tomorrow then! It'll be raining according to the forecast so I can't progress with the job anyway.

Andy

[Chris Bacon]

Isn't it the case that ties made at some period were BZP'd, or somesuch, and cause problems due to the very thin coating, but the ones from the first period of cavity wall building (early C. 20th.) were heavily coated by hot dipping, and rarely cause problems?

Dunno whether that's right or not, but stainless are a much better bet.

[Andy]

My actual house cavity wall ties ( 1939 ), which are like a galvanised solid square bar with fishtailed ends, are in perfect nick, I've seen a couple where I've had to knock bricks out.

I got onto Screwfix this a.m., and the operative called up the Tech Support section, and they agreed that I needed the SS wall tie system and have arranged a swap, no problems.

If they have a joined-up organisation the description of this wall tie system on their website will change in the near future to stop it being so misleading, but I'm not holding my breath.

Andy

[dg]

A galvanised tie can potentaily corrode after the coating is breached, and it would require some significant rough handling and then the moist air in an open cavity.

Built in to solid mortar you will get a service life of at least as long as the rest of the wall.

dg