Hi All
Yesterday I had some brickwork laid, finishing in the evening... and
last night there was a minor frost here. Is that likely to be a
problem? If so what would be the symptoms of this?

Rgds., Tom

In article ,
Tom writes:
Hi All
Yesterday I had some brickwork laid, finishing in the evening... and
last night there was a minor frost here. Is that likely to be a
problem? If so what would be the symptoms of this?

If the mortar froze, then it will never be as strong as if it hadn't
frozen (I was taught that it sets no further from that point on, but
I haven't ever seen any supporting evidence for this). However, a minor
frost does not mean the temperature dropped below zero. There was a
white frost all around me this morning, but some part-built brickwork
I have which had pooled water in it from yesterday's rain had no sign
of ice in the water, because the temperature actually didn't drop below
2C.

You should protect new brickwork from freezing, such as covering
it up and/or using a low temperature additive in the mortar.
When I was building a gatepost a few years ago and was expecting a
frost one night, I put hot water into a number of 2litre coke
bottles and put them in the hollow middle of the gatepost, with the
gate post cap resting on top to keep the heat in (or at least force
most of it to escape through the brickwork, keeping it from freezing).
That seemed to work well.

Mortar takes around 6 weeks to reach full strength, and you should
probably protect it for as much of this as you can for max strength.
(OTOH, you rarely actually need max strength.)

--
Andrew Gabriel
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