Hi Ben,
I made some changes. Check that I haven't accidentally changed your meaning, particularly in the second half.
When you finish this work, please come and help me with my drain-pipes, OK?
Best wishes, Clive
Re: The addition of drain pipes
Referring to your verbal site instruction, dated 12 Nov 2005, concerning the additional drain pipes for the air conditioning units, the installation problems have been solved with the main contractor. The material for the drain pipes has been kept in stock after liaison with our supplier.
On the other hand, the installation of drain pipes is not included in our contract. In order to keep to our tight progress schedule, the installation will commence now since a written confirmation or instruction for the additional works has been issued to us.
If you have any queries, please free feel to contact me at tel:68680000000