Multiple Layers of Shingles: Why It’s a Common Problem on Older Greenville Homes
If you live in an older home in Greenville, there’s a decent chance you’ve got more roof than you think.
We regularly find multiple layers of shingles - sometimes two, sometimes three. Most homeowners don’t know it’s there because you usually can’t tell from the ground.
This comes up when someone calls with a leak or a recurring roof issue, and we start digging into why it won’t stay fixed.
Why roofs ended up with multiple layers
Years ago, it wasn’t uncommon for someone to add another layer of shingles instead of removing the old roof.
And a lot of the time, it happened because:
the original problem wasn’t identified correctly
repairs didn’t hold
adding a layer felt like a quick “cover it up” solution
It’s often a sign that the roof was treated like a surface problem instead of a system problem.
What today’s code requires
Today, building codes require a proper tear-off in many situations, and re-roofing over multiple layers is not allowed in most modern permitting situations.
(Exact requirements can vary by roof type and conditions, but the direction is clear: stacking layers is not the standard.)
Why multiple layers are a nightmare
Multiple shingle layers create problems that homeowners don’t expect.
1) Extra weight on the roof
Shingles are heavy - especially when you stack layers.
That added weight:
stresses the structure over time
can worsen sagging or decking issues
creates long-term risk, especially on older framing
2) It traps heat and moisture
This is the big one.
Multiple layers can trap heat and moisture the same way aluminum foil over a pan in the oven traps heat and “steams” what’s underneath.
Instead of drying out, the roof system can stay warmer and wetter where it shouldn’t.
That can lead to:
faster shingle aging
damaged or rotted decking
mold risk in the wrong conditions
shorter roof life overall
3) Leaks get harder to trace and fix
With multiple layers, water can move between layers and show up in unpredictable places.
That makes:
diagnosing the real entry point harder
repairs less reliable
recurring leaks more common
If you’ve ever felt like your roof leak “doesn’t make sense,” multiple layers may be a major reason.
How to tell if you have multiple layers
Sometimes you can spot it at:
roof edges (drip edge area)
rakes and eaves where shingles stack
attic inspection (decking condition can hint at trapped moisture)
But most of the time, it takes a trained eye on an inspection.
What homeowners should do with this info
Finding multiple layers doesn’t automatically mean you need a full project tomorrow.
It does mean:
your roof issues may be more complex than they appear
quick repairs might not hold the way you’d expect
an inspection is worth it before spending money twice
