On Fri, 12 Sep 2008 10:42:57 -0700, meow2222 wrote:

On Sep 12, 11:27Â*am, The Natural Philosopher wrote:
wrote:

Corrosion is only a problem when the concrete contains flyash.

Total ********. All pip[es corode when there is a mixture of air and
water,

but not to a problematic extent

and any acid makes things worse.

concrete of course is alkaline


Fortunately screed sis fairly
alkaline, so tats on there, but there is still a possibility of dampness
due to absorbed moisture.

yes, which doesnt lead to corrosion in plain mixes without flyash.
We've been thru all this before.

So if you've got pipes already embedded in concrete how do you know
whether it contains flyash or not?

There was a photo in CORGI's Gas Installer magazine this month showing a
length of copper pipe which had been installed running along an external
wall. One secrion of the pipe was in contact with mortar and had corroded
right through.


--
John Stumbles

Seagull Management
Management technique characterised by flying in, making a lot of noise,
crapping on everything, and then leaving.