"Tim Lamb" wrote in message
...
In message
,
Osprey writes
On 29 Oct, 11:19, Tim Lamb wrote:
I am lifting the roof on an old pig farrowing barn to accommodate a
furniture restorer.

The roof is heavy but can be moved in one piece. So far I have raised
one side on Acrows and intend to lay two courses of brick to gain the
height needed.

What is a reasonable time to wait before heavily loading fresh
brickwork? I am particularly nervous of any side thrust encountered as I
start to jack up the other side.

regards
--
Tim Lamb

I would leave it 48Hrs ... 24 Hrs is no problem if a simple daed load,
but as you point out there is side thrust, and bricks not particularly
strong in that direction.

use a good 3:1 mix and suitable bricks, deep frog frettons as a
minimum, laid frog up, and fully filled ... or engineering if you have
them.

OK. The brickwork will be Flettons for the first course and
semi-engineering for the top. Basically because that is what I have lying
about the farm:-) I can easily wait 3 days as I also have to fit a wider
door and re-plumb the electrical conduit.

regards
--
Tim Lamb


Tim .... my comment about 48 Hrs is a practical one, if you are using an OPC
& sand mix .... it would have enough partial strength after 48 Hrs.
If you have any doubt use rapid set cement ... or an accelerator additive.

If you can leave it longer then all the better.

Some of the other comments about exothernmic reactions, and time to
compressive strength are valid for bulk concrete, but not that relevant for
coursed brickwork.

Obviously the longer you leave it the more strength it has, but courses and
lintols (=dead load) are built up next working day on site.