Add a Polycarbonate Roof to the Pergola You Already Have.
Already have a pergola that leaves you soaked in a rainstorm and baking in August? You don't need a new structure. We install the Hercules polycarbonate roof system onto existing pergolas across Denver and the foothills — most in a single day.
A pergola with open slats gives you shade and not much else. A polycarbonate roof turns the same structure into a genuinely covered patio: dry in the rain, protected from hail, and usable for most of the year instead of a few pleasant weeks.
HERCULES SYSTEM — BRONZE
HERCULES SYSTEM — ICE WHITE
What a Roof Actually Changes
The structure stays. The way you use it doesn't.
You Stop Going Inside
An uncovered pergola is a fair-weather structure. Once it's roofed, a rainy afternoon stops ending the party — and outdoor furniture, cushions, and a grill can live out there without being hauled in and out.
Front Range Hail Protection
Denver sits in one of the most hail-prone corridors in the country. Multiwall polycarbonate is built to take an impact that would wreck an acrylic or vinyl panel, which is why we won't install anything lighter here.
Shade Without Darkness
The panels block UV while still passing daylight through, so the patio stays bright and the room behind it doesn't go dim. Tinted bronze knocks down heat and glare the way sunglasses do.
Rated for Colorado Snow
The Hercules system carries a 50 PSF snow rating with purlins spaced correctly, and is warrantied to 40 PSF. Most house roofs are engineered in the 20–30 PSF range, so this is not a light-duty cover.
Usually a One-Day Job
There's no design phase, no footings, no permit process in most cases. We measure, order the panels to length, and install. Most retrofits are finished in a day once material arrives.
A Fraction of a Rebuild
Roofing a pergola you already own costs a small share of what a new covered structure would. The posts, beams, and footings are already paid for — you're only buying the roof.
Why We Install Hercules and Nothing Else
Hercules is a multiwall polycarbonate system built around 8mm four-wall standing-seam panels. The four-wall structure is what gives the sheet its rigidity, and the standing seam is what makes the finished roof leakproof rather than merely water-resistant. Cheaper corrugated and single-wall panels are common on retrofits and they do not hold up to a Front Range hailstorm.
Panels come in tinted bronze, translucent clear, and reflective white. Bronze is what most of our customers choose — it cuts heat and glare while still letting you see sky through the roof. White reflects the most heat but is opaque. Clear passes the most light and reduces temperature the least, which is rarely what anyone wants in Colorado.
Hercules System Specifications
SKYPOLY MULTIWALL POLYCARBONATE — MANUFACTURER RATINGS
Maintenance is basically nothing. A hose handles normal dirt and pollen. Tree sap comes off with diluted dish soap. There's no sealing, staining, or annual service.
Your Pergola Needs Slope — and If It Doesn't Have Any, We Add It
A polycarbonate roof has to shed water. The Hercules system requires a minimum 2% slope to stay under its leakproof warranty — that works out to about one inch of drop for every four feet of run. Without it, water pools on the panels, algae takes hold in the standing water, and the warranty doesn't apply.
Plenty of pergolas around Denver were built dead flat, because a slat-top pergola never needed to drain. That's not a dealbreaker. We build the slope in by adding tapered shims or purlins across the existing rafters, which raises one end without moving or replacing the structural members. We check slope in several places during the site visit, since a patio that slopes away from the house can make a flat pergola look like it drains when it doesn't.
Slope
Measured on top of the structure with a four-foot level, in multiple spots. One inch of fall or more and you're ready as-is.
Rafters or Purlins
Panels can't be trimmed to fit, so the members they fasten to need exact spacing. Pergolas with only wide-set rafters get purlins or blocking added on top.
Condition of the Wood
Once the roof is on, what's underneath is hard to reach. Rot repairs and a fresh coat of stain are far easier to do before the panels go up than after.
What a Polycarbonate Pergola Roof Costs in Denver
Most people want a number before they want a consultation, so here's ours. Pricing is by the covered square foot, installed, using the pergola's existing footprint.
Polycarbonate Roof — Retrofit
INSTALLED PRICE PER SQ FT — EXISTING PERGOLA
Three common sizes at the starting rate, roof only:
Example Projects
HERCULES PANELS INSTALLED ON AN EXISTING PERGOLA
Compare that to building a new covered structure from scratch at $30–$32/sq ft for the pergola alone, before any roof. If the bones of your pergola are sound, roofing it is the cheapest way to get a covered patio.
From Call to Covered
Site Visit
We measure the footprint, check slope in several spots, look at how the rafters are spaced, and inspect the wood. Free, and you get a number before we leave.
Panels Ordered to Length
Sheets are cut to your pergola's run rather than pieced together, which is a large part of why the finished roof doesn't leak. Typical lead time is one to two weeks.
Prep and Install
Any shimming, purlins, repairs, or stain happen first. Then panels, seams, edge profiles, and flashing go on — usually finished the same day.
We Build Them Too
If there's nothing to retrofit, we design and build custom cedar and treated pine pergolas across Denver and the foothills — with the roof engineered in from the start, sloped correctly the first time.
See Custom PergolasPolycarbonate Roofs We've Installed
See more in the full gallery.
