Glossary O Terms
OPC
Ordinary Portland Cement manufactured to BS 12. We call OPC grey cement. We generally specify Rapid Hardening cement which achieves higher early strength. RH is more finely ground than OPC and therefore has a higher specific surface area, which hydrates faster.
Open Book
A technique used as part of our contract negotiations to demonstrate fair value. Open book negotiation can save a great deal of time.
Open Drained Joint
See Drained Joint.
Outer Leaf
The outer skin of a cavity wall. All of our cladding panels form the outer leaf in effect, although panel construction may be backed with a fast build, thermally efficient dry lining