[Moderator David@stives]

I know this is a strange one .
 
 I belong to charitable organisation and have been given the task of finding out the best way to clean our marquee which we hire out to bring in funds .
 
the Marquee is about 50 feet in length and is full  of mud stains mostly as we put it up in muddy fields etc .
 
I know it will probably need waterproofing again afterwards.
 
the material is a very strong canvas . that is all i know
 
yhanks in advance
 
Dave

[magic_carpet]

david give me a call. i'm in st.agnes 07816756375.
i've done i few heavy canvas shop front blinds which are probably much the same.
i may be able to help--or why not call a marquee firm and ask them what they do.
good luck