GAF ArmorShield II Class 4 Roof Replacement on Prairie Knoll Drive in Longmont, Colorado

The Problem

Vanda and Bob's home on Prairie Knoll Drive in Longmont, CO had a roof that was about 27 years old. The shingles were quite brittle, with poor gutter apron/drip edge coverage at the eaves, and torn ridge cap shingles Water was entering the roof at the eaves and split ridge cap. The roof was at the end of it's life, and roof repairs on shingles in this older condition typically don't last. Simply time for a new roof on this home.

What We Did

Vanda chose GAF Timberline ArmorShield II Shingles in Weathered Wood, which is one of our most popular shingle colors. Armorshield II Class 4 impact-resistant shingle offers the best hail protection in WestPro's lineup while keeping costs reasonable. Class 4 shingles are also now required for re-roofing projects per the Boulder County Building Department. On the Colorado Front Range, where hailstorms are a regular reality, the Class 4 rating can also qualify homeowners for an insurance discount that helps offset the upgrade cost. The roof came in at about 50 squares, and the project included four new Velux EDL C06 flashing kits to properly re-flash the existing skylights.

One thing worth noting: before the installation even began, the team spotted exposed wood along a ridge on the southwest corner of the roof. Vanda was understandably concerned about moisture getting in before the replacement date, so WestPro sent a project manager out to install a protective tarp in the meantime. That small step gave her peace of mind during the wait. The new roof installation took place in April of 2026, and took just 2 days to complete given the larger size and steeper 9:12 pitch. The project then passed its Boulder County Building Department final inspection.

Project Details

The roof on this home measured 50 squares, which works out to approximately 5,000 sq ft of roofing surface. The pitch is a steep 9:12, which adds complexity to the work and requires extra care from the crew during installation. Four flashing kits were also part of the scope to address the roof's penetrations and transitions. The entire roof was removed and plywood sheathing inspected. New drip edge flashing was installed at the eaves, with 2 courses of GAF Leak Barrier were applied to the eaves and valleys for additional leak protection. Our roofing crew also replaced 13 slant back style roof vents and added 4 more to bring the roof and attic ventilation up to modern building code and shingle manufacturer standards. Plus it will keep their house a little cooler.

Materials Used

GAF Armorshield II Shingles in Weathered Wood color

GAF Weatherwatch Leak Barrier

Velux skylight flashing kits

GAF Seal-A-Ridge IR Ridge Cap Shingles

GAF Pro-Start

2"x4" Pre Finished Drip Edge Flashing

Pre Finished step flashing

The Result

This project was completed by WestPro Home Exteriors in 2026. Vanda was happy with the final result, from the pre-installation tarp that protected her home during the wait, to the new GAF ArmorShield II roof that passed its Boulder County inspection without a hitch. It's a great example of the kind of work WestPro does for homeowners across Longmont and the Colorado Front Range.

Homeowners with similar roof replacement projects can expect to pay approximately $7.60 - $8.70 per sq. ft. for steeper roofs like this that also include upgrades or code requirements that include Ice and Water shield/Leak barrier, skylight flashings, additional ventilation, and high quality class 4 shingles. Keep in mind that exact pricing may vary depending on site conditions, roof sheathing, ventilation requirements, and other details. For exact pricing, a roof inspection and estimate is required.