tile grout cleaning question

[Bruce]

No, they aren't. You can deceive yourself as much as you like, but even the whitest grouts are not remotely "bright" white.

You never have - so try taking your own advice for a change.

[The Natural Philosopher]

The secret motto of conversationists is to make the repair as rotten as the original was, so they don't do themselves out of business ;-)

I believe portland cement was first used in major form to construct the giant sewer that runs under the embankment.

Its already lasted longer than most lime mortar houses have..

But never allow facts to affect dogma eh?

[Bruce]

Portland cement is the basis of most modern construction. But it does have its weaknesses, one of which is its strength - IYSWIM.

[The Natural Philosopher]

White cement s pretty bright white, but I suspect white grouts also contain gypsum and titanium oxide. Certainly some gypsum is IIRC in ordinary cement anyway..

Mmm. Read wiki on 'portland cement' and 'white portland cement'. Fascinating.

[John Rumm]

Was not doubting its existence, just did not think it was a common as the powdered cement based type.

The last one I used was a Nicobond powdered grout - cement based and very "white". I don't think cement poses any limitation on colour (or lack of)

You can make springs (and lots of other non intuitive things) out of concrete if you want! You can get flexible boat hulls made from concrete as well.