Hello,

I am trying to understand the Pro/Con of Acrylic vs Silicone coatings.

Location: Hawaii (warm all year, very high UV, no heating)

Home: Single story 1960’s shallow pitch (2:12) with very low slope enclosed patio (but water does run off — not completely flat – no ponding). No air conditioning (yet).

Roof: ¾” Plywood + 2-ply Bitumen

PROBLEM: Home is HOT due to no insulation over high open beam ceilings

DESIRED EFFECT FROM ROOF COATING:

1. Reflectivity to cool home (hoping for 10 degrees)

2. Durability

3. Affordability

I hear rumblings about the need to recoat after some period of time

I have also heard aobut dirt and dust sticking/attracted to some coatings more than others which leads to algae growth/accumulation of debris that reduces reflectivity.

Commonly used products I have seen – 

• Lots of GACO silicone

• Some APOC silicone

• Henry’s silicone

Any favorite products out there, and why?