FlowGuard Slip Under Shingle Gutter Cover System - 22 ft White

Our review of the FlowGuard USA Made Slip Under Shingle Gutter Cover finds it best for homeowners who want a durable, low-maintenance solution to clogged gutters. The single biggest reason to buy is its heavy gauge.018 painted aluminum construction and under-shingle design that permanently mounts with stainless steel fasteners, which together keep leaves out while allowing heavy rain to flow freely. Installation is straightforward for DIYers comfortable working on a ladder, and the product's 50-year warranty makes it a long-term investment in protecting foundations and siding.

Key Features

• Made in the USA: Manufactured entirely in the United States, which ensures consistent build quality and local support.
• High strength aluminum:.018 heavy gauge painted aluminum resists rust and long-term deterioration for durable protection.
• Under-shingle design: Permanently installs under shingles with included stainless steel fasteners to resist extreme rainfall, snow loads, and wind.
• 3-point debris control: The raised 3-point pattern keeps wet leaves off the surface so airflow and wind remove dried debris over time.
• Easy to install: Dual interlocking ends, simple cutting with tin snips, and included zip screws make continuous runs straightforward for experienced DIYers.
• 50-year warranty: A long manufacturer's warranty provides peace of mind about durability and performance.

Who It's For

The FlowGuard is ideal for homeowners with standard 5 in or 6 in gutters who want a permanent gutter guard that integrates under shingles and stands up to harsh weather. It suits DIY installers who can safely work on ladders and have basic metal cutting tools, since installation uses stainless steel twin thread pierce point zip screws and tin snips.

Those with unusually narrow or nonstandard roof-to-gutter spacing should check fit first, since some customers reported mixed feedback about width compatibility. If you prefer a removable system for easy inspection, or cannot lift shingles at the eave, a surface-mounted or removable style might be a better choice.

Pros & Cons

Pros

• Durable.018 aluminum construction that will not rust and is backed by a 50-year warranty.
• Under-shingle mount and included stainless steel fasteners hold up in heavy rain, snow, and wind.
• 3-point design and drain geometry keep water flowing while preventing debris buildup.
• Generally praised for ease of installation and good value for money.

Cons

• Width compatibility received mixed feedback, so measure roof-to-gutter spacing before ordering.
• Requires working under shingles and on ladders, which may deter inexperienced installers.

Specifications

Our Verdict

The FlowGuard slip under shingle gutter cover is a solid choice for homeowners seeking a permanent, rust-free solution that keeps gutters clear in heavy rain and wind. Its heavy gauge aluminum, thoughtful 3-point design, and included stainless fasteners provide long-term value, but confirm width fit and be prepared to work under shingles during installation.

Frequently Asked Questions

Will FlowGuard work with 5 in and 6 in gutters?
Yes, the product is made to fit standard 5 in and 6 in gutters, but measure your roof-to-gutter gap to confirm proper width compatibility.

Are fasteners included for permanent installation?
Yes, stainless steel 1/2 in #8 twin thread pierce point zip screws are included for permanent attachment under shingles.

How durable is the material?
The cover is.018 heavy gauge painted aluminum that resists rust and comes with a 50 year manufacturer's warranty to ensure long-term performance.