insulation Paint??

[soundman]

I have seen advertising and other mentions of thermal paints recently thats about all though.
Have you made sure that the outside is painted a light coulour like white.

Don't think for a minute that canvas is any less flamable than other fabrics. Most canvas burns real well because it is impregnated with oils & waxes to make it waterproof.

If flamability is a concern theatrical curtaining suppliers can treat fabric with flame retardent chemical such as "ROSCO Flamex".

The curtain will also help heaps with the noise.

cheers

[echnidna]

The old english warships used to fireproof their canvas sails by soaking them in a solution of Alum.

[soundman]

Modern fire retardants used in theatre are borax based but ther is a coctail of other chemicals to make the product disperse thru the fabric and prevent it from misbehaving in varoius ways.
Flamex (& similar) is available through most serious theatrical suppliers.
Usualy applied by dipping or spraying, But do it outside as it corodes metal just like salt.