Soaker hose to cool house roof?

Use a "soak-n-spray" hose......it puts out lots of very small streams down the length of the hose. Ours is installed at the peak of the roof and draining to both sides.....metal roof.....no insulation. It drops the ambient inside my cabinet shop a good 10F during hot summer months. The volume of water used is not that much as we only turn it on manually during the hottest of days here in southwest Mississippi.