the noise when it rains is very loud. can I place an insulation material under the polycarbonate roof to reduce noise? Thanks
Sure, depending on the roof space anyway.
You can put it up there, but it's effectiveness at cutting noise would depend on the thickness of the insulation but you should not hope for too much reduction as the hard poly roofing is screwed or nailed directly to the rafters and is a good medium for sound transference.
