Specialty and New Doors

Smooth Slim Profile 4 Lite Horizontal Flush-Glazed Fiberglass Door

SKU: S-SP4LH-FG

Key Features:

- 1 3/4″ door thickness
- Stability with special slim profile 3.94″ full length LVL stiles and 4.53″ LVL rails
- 100% no-rot PVC sealed edge with 1/2″ PVC on the stiles and 3/4″ on the rails
- 2.5 mm thick fiberglass skin to reduce flexing and distortion
- Automotive-grade polyurethane adhesives and proprietary adhesion techniques keep Patson Doors from delaminating even under the most severe conditions
- UV and mold resistant lacquer applied to all doors to prevent discoloration and mold
- Pre-hung units are hung in no-rot PVC brickmold and PVC 4 9/16 or 6 9/16 jamb options and use adjustable ORB thresholds, weatherstipping, sweep and hinges
- NOTE: due to the slim profile of this door’s stiles, specialty hardware is needed

Matching Sidelites:

Specifications

Width Options:

30", 32", 36"

Height Options:

80", 84", 91"

On Roadmap for Pending Development:

96" Heights

Special Notes:

Speciality Narrow Profile Hardware Needed

Prehung:

Singles, Doubles, Sidelite Units and Knockdown Kits Available

Prep:

Custom and Standard hinge prep and bores available

Door Edge:

Square Edge with Proud Edge upon request

Finish Options

1000's of RAL color options available for painting and staining.

Add On's Available

Storm Door Attached, Knocker, Peephole, Specialty Hardware, Custom Skin Molds, Custom Glass Designs, PVC Lock Block, Trimmable/Larger Stiles and Rails, Craftsman Drip Shelf

Industry Pain Point

1. Rot and Moisture Intrusion

Patson Door Solution:

1/2" PVC edge on styles and top rail and 3/4" on bottom rail

Moisture damage is the leading cause of door failure. Patson Doors eliminates this with a complete no-rot system, featuring full-length LVL stiles and rails with PVC edges that create a sealed moisture barrier. Optional PVC lock blocks provide added reinforcement against infiltration. Testing shows zero swelling or rot per ASTM D1037 with dimensional stability maintained through acceleration ageing test.

2. Delamination

Patson Door Solution:

Better Glue + Better Process.

Delamination has long plagued fiberglass doors, often caused by subpar adhesives, rushed curing and moisture intrusion. Patson Doors solves this with our exclusive manufacturer, Polychemical Fibroplast, using automotive-grade polyurethane adhesives proven in 25+ years of car production. These non-toxic glues undergo environmental, heat-aging (-25°C to 95°C), and pull-strength testing to ensure long-term bond integrity. Paired with our full PVC no-rot edge system and optional PVC lock blocks, every Patson Door resists moisture, rot, and delamination.

3. Warping

Patson Door Solution:

Better Full legnth 1.25" LVL stiles and top rail and 1.75" bottom LVL rail+ Better Process.

Patson Doors eliminates this issue through 1.5"-1.75" LVL thick stiles, rails, a 4.13 x 10" lock block and rigid high grade cores, engineered to maintain shape through extreme temperature and humidity cycles. The deflection tollerance for our doors is +/- 2.5mm which ensure our doors stay straight, true, and reliable.

4. Flexing and Surface Distrotion

Patson Door Solution:

2.5mm Thick Fiberglass Skin

Through thicker fiberglass skins — 2.5mm skin thickness, compared to the industry standard 2mm — plus precision cores and advanced molding controls from our partner Polychemical Fibroplast, every Patson Door stays true and flat, even under heat and pressure within +/- 0.5mm of deflection tolerance. The result: lasting strength, more energy efficiency, stability, and a flawless surface finish.

5. Uneven foam fill and blank spots

Patson Door Solution:

Clear Skin Inspection Process

Uneven foam fill weakens structure and insulation. Our manufacturer’s clear-skin inspection process enables real-time verification while injecting the ridgid Polyurethan foam core, ensuring complete, consistent core density. Every door’s foam core achieves density 35kg/m3, resulting in superior strength and insulation values (R-value avg 3.7). The process ensures doors meet ASTM C578, producing a uniformly filled door that’s stronger, quieter, and more efficient.

6. Discoloration from UV or Mold

Patson Door Solution:

UV and Mold resistant laquer applied to all doors

Every Patson Door features a UV-stable, mold-resistant laquer that has been tested to standard ASTM G155 testing. The result: a durable, low-maintenance finish that stays vibrant and protected for years.

Lack of Originality

Patson Door Solution:

Constant Innovation and Engineering

Most fiberglass doors look the same — same styles, same designs, little innovation. Through our exclusive partnership with Polychemical Fibroplast, a decades-old mold-making expert, we’re changing that. With advanced engineering and custom tooling capabilities, we continuously develop new designs and styles, bringing fresh, distinctive products to market ahead of the industry.

Global Supply Chain Volitity

Patson Door Solution:

US Distribution/India Manufacturing

In a volatile global market, stability matters. While most fiberglass door brands rely on the same regional suppliers, Patson Doors offers a stronger, more diversified supply chain. Our U.S.-based distribution combined with exclusive manufacturing in India keeps production flowing smoothly and reduces exposure to global disruptions — ensuring reliable availability and consistent quality, no matter the market climate.

Related Products

Brushed XL Fullview Flush-Glazed Fiberglass Door

Combination Mobile Home Door with Smooth Camber Top with Flush Glazed with Raised 4 Panel Bottom Fiberglass Door and Attached Storm Door NOTE: Combo can be made with any style door or storm door

Smooth Slim Profile 1 Lite Flush-Glazed Fiberglass Door

Smooth Slim Profile 4 Lite Cross Flush-Glazed Fiberglass Door

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