An asphalt shingle roof is a composite: a fibreglass mat, asphalt, and a layer of granules pressed into the top. Every way it ages comes back to one of those three layers losing something it needs.
Heat that never leaves the roof
A roof deck that cannot breathe holds heat and moisture under the shingles. The asphalt softens and re-hardens through the day, the mat works against the fasteners, and the whole assembly ages faster than the same roof with proper intake and ridge ventilation.
Ventilation is the first thing worth checking on an old roof, because it is also the cheapest thing to fix, and no surface treatment can compensate for an attic that traps its own heat.
Sun, and the oils it takes
Ultraviolet light breaks down the light oils that keep asphalt flexible. Once they are gone the shingle dries out, becomes brittle, and starts to crack at the edges rather than flexing with the roof moving underneath it.
This is the part a nano treatment is designed to slow: putting the oils back into the surface and shielding it from further UV rather than coating it over.
Algae, moss and what they leave behind
The dark streaking most homeowners notice first is algae feeding on the limestone filler in the shingle. Moss holds water against the surface instead of letting it run, keeping the shingle wet for days after rain.
Both are signs that the surface has become a good place for growth. Cleaning removes what is there; a surface that sheds water gives it less to come back to.
Freeze-thaw, the quiet one
Water that has soaked into a shingle expands when it freezes. In a climate with repeated freeze-thaw cycles, that movement happens dozens of times a winter, working at the same edges and seams until they open.
A surface that repels water has far less to freeze in it, which is why water repellency and freeze-thaw resistance are the same conversation.
What actually slows it down
Fix the ventilation, clear the growth, repair what has failed, then protect what is still sound. That order matters: a treatment protects a working roof, it does not rescue a failed one.
Our free assessment scores the roof before anything is quoted, so you know which of those four steps your roof actually needs.
Source
Written for Dr. Armor. The original GoNano article this guide draws on: Why is my shingle roof aging faster than it should?
Questions
Common questions, answered in full
- How long does roof rejuvenation last?Coverage runs from 3 to 20 years, and the roof’s condition score decides which.
- Can you treat a roof that is leaking?No. A leak is a repair job and has to be fixed before any treatment.
- What does the warranty cover?Peeling, curling or warping caused by the treatment, and water getting through.