Message text written by "BP - \"Is this the list with all the ivy
haters?\""
> 
Mike

I know that we are trying to get your products over here, and maybe one day
we will have some success.  In the meantime, we have to make do with the
local concrete repair mortars.  Most of these are polymer modified ... but
still require curing if you read the manufacturers instructions (and even
so called good tradesmen don't seem to be able to do that).<

I am aware that some of the large concrete repair mortar manufacturers have
gone back to a wet-curing requirement (though a limited one). I have
pondered that decision and can only conclude that a lot of these moratrs
are fairly cement rich, so the polymer-cement ratio ends up being a little
low, thus they may not get the full benefit of ambient curing.
Alternatively, you've got a hot, dry windy climate and just need to wet
cure! 

>With regard to reinforcement, I guess I have a fundamental problem with
patches being installed without reinforcement and dowels anywhere that the
patches are unsupported or on the underside of projecting courses.  And
unfortunately, that represents a lot of our patches.  Depth is usually in
the region of 1-1.5"  (25-35mm) - if I have to go to 2-3" (50-75mm) then I
will specify an indent because I don't want that sort of buildup in my
patches.

Also, my dowels are typically only 3mm (1/8") and my reinforcement is
usually 1.2mm diameter wire (1/20").  I know I don't get great cover, but
my stainless is not going to corrode, and at that size, my differential
thermal expansion is less of a problem.<

Interesting viewpoint, to which I will give some thought. 

>I also limit the maximum size of my patches to about 400-500 mm (16-20")
in dimension - I really don't like the idea of the differential thermal
expansion between the patch and the stone for such large areas.

I know that theoretically these can be avoided ... but I can't get good
repair mortars, let alone good tradesmen, and as for the fee to inspect on
site ... forget it!  I'm lucky if I can get a fee to document the work
properly sometimes!<

Agreed, the differential in coefficient of thermal expansion can be a
factor if you can't get something meant to match more closely. And though
concrete and siliceous sandstones can be fairly close in coefficient of
thermal expansion, you may have all sorts of other mechanical
incompatibilities which suggest that limiting patch size is a good idea.

Oh well, got that off my chest ... look forward to your comments.  And yes,
I hope to try again to spec your repair mortar in the not too distant
future.

Cheers

david<

I wouldn't need much of an excuse to schedule a trip to Australia, which
I've always wanted to visit anyway. Perhaps the motivation will present
itself "in the not too distant future".

Regards,
Mike