"Phil L" wrote in message
.uk...
Adam wrote:
We had some roofing contractors replacing the flashing on our flat
roof earlier this week. They left the job unfinished, as it was
raining at the time, and said that they couldn't cement the flashing
in place while it was raining. This sounded reasonable, and I
believed them.
They came back today to finish the job. It was raining again this
morning, but they went ahead and did it anyway.

So, were they just looking for an excuse to skive off early when they
were with us earlier in the week, or is the cement they put in place
today not going to set properly?

Cement sets by chemical reaction, so it will go off under water. Some large
yachts even carry a sand and cement mix for running repairs if they get
holed. The only problem is if it washes out of position before it goes off.

Colin Bignell