| We put wooden laths about 1/4 " thick wrapped in polythene bags between the panels when the concrete was poured - eased them out when the concrete was still "green".
We had a drum of tar spare after filling some electrical junction boxes- melted it and poured that in the slots when the concrete was fully cured.
Have no idea if that is the correct way but it was what was available on site and is still as good as the day we did it.
16 years ago !!!
(The re-bar mesh was cut at the joints) |