Lifetime seam warranty
Therma-Seal seams are covered 100% for the life of the liner.
Overlap Expandable Liners
Doughboy Overlap Expandable Liners
Overlap expandable liners drape over the top of your pool wall and stretch into a dug-out hopper bottom for a deeper swim area, up to roughly 7 feet, in both 20 MIL and premium 25 MIL.
General Liner Info
Liner Features & Benefits
Doughboy overlap expandable liners install with coping strips over the top of the wall and are built to stretch into a hopper-bottom installation. Choose 20 MIL (Overlap 4000 Exp) for the standard performance build, or 25 MIL (Overlap 5000 Exp) when you want the premium, thicker-gauge option.
100% virgin vinyl
No clay fillers and no reprocessed material, UV- and chemical-resistant.
True mil thickness
Measured in real mil, not the marketing "gauge" other brands use.
Warranty-safe fit
Genuine Doughboy parts so your pool warranty stays intact.
What you get with every overlap expandable liners
- Refresh your pool's look with a vibrant, high-quality liner print.
- Designed for consistent fit and smooth installation when matched to the correct pool size.
- UV- and chemical-resistant vinyl helps reduce fading and wear from normal pool care.
- Special 100% virgin-vinyl formula that resists chemicals and ultraviolet rays.
- Therma-Seal™ Technology, sealing technique that provides durability and supreme quality.
- Liner seams come with a 100% lifetime warranty.
- Pair with proper water balance and a quality underlayment for best long-term results.
2026 Patterns
Doughboy Overlap Expandable Liners, Pattern Lineup
Browse every pattern currently available in this series. Stop by the Modesto showroom to see physical swatches and confirm the right size for your pool.
Premium 25 MILBlue Topaz
25 MIL · Full print on white
Mosaic of blue square tiles on the premium 25 MIL Overlap 5000 Exp build.
Misty Falls
20 MIL · Full print on white
Soft blue and white marble-style pattern.
Solid Blue (20 MIL)
20 MIL · Solid
Classic solid blue, clean, timeless, and budget-friendly.
- Premium 25 MIL
Solid Blue (25 MIL)
25 MIL · Solid
Same classic blue, upgraded to premium 25 MIL vinyl.
Sunset Cove
20 MIL · Printed pattern
Warm, beach-inspired print that brightens the whole backyard.
Note: pattern colors on screen are a guide only, actual liner color and texture may vary slightly between print runs.
Gauge vs. Mil
The Most Confusing Number In The Above-Ground Liner Aisle, Explained
"Gauge" is a marketing term. "Mil" is a real measurement. Before you spend money on a replacement liner, here's exactly what the numbers mean, and why a true mil-rated Doughboy liner is almost always thicker than the gauge number on a competitor's box.
Mil is a real measurement
One mil equals 1/1000 of an inch. A 20 mil liner is exactly 0.020" of vinyl, the same on every box, from every manufacturer. When Doughboy says 20 mil or 25 mil, you can put a caliper on it and prove it.
Gauge is a marketing term
"Gauge" has no fixed conversion to a physical thickness. Manufacturers use it to make thinner vinyl look thicker on the shelf, and in many cases, "30 gauge" is only "approximately 15 mil." It also lets them use thinner vinyl on the floor than on the wall.
Industry "Gauge" vs. actual thickness in mil
Approximate conversions reported by liner manufacturers and the broader plastics industry. Numbers vary by brand, always ask for the actual mil thickness in writing.
| Marketed gauge | Wall (actual mil) | Floor (actual mil) | What it really means |
|---|---|---|---|
| 20 Gauge | ~11–13 mil | ~12 mil | Marketed as the "standard" but is the thinnest vinyl on the market. |
| 25 Gauge | ~14–15 mil | ~13 mil | Often sold as an "upgrade", still thinner than a true 20 mil Doughboy liner. |
| 30 Gauge | ~15–17 mil | ~15 mil | Frequently described as "approximately 15 mil" in the fine print. |
| 35 Gauge | ~18–19 mil | — | Thickness and floor weight vary by manufacturer. |
| 40 Gauge | ~20–22 mil | — | Top of most gauge charts, still no guaranteed floor thickness. |
Source: published manufacturer charts and the U.S. plastics-film convention that 100 gauge = 1 mil. Pool-liner "gauge" is not the same scale, which is exactly the confusion this chart exposes.
What Doughboy actually delivers
Doughboy is the only above-ground pool brand that manufactures its own vinyl, in true mil thickness, with the same gauge on the wall and the floor, backed by the Therma-Seal lifetime seam warranty.
| Series | True thickness | Warranty |
|---|---|---|
| Overlap 4000 / E-Z Clip 4000 | True 20 mil wall and floor | 20–25 year limited warranty |
| Overlap 5000 Expandable | True 25 mil wall and floor | 30 year limited warranty |
| Therma-Seal seams | Heat-welded virgin vinyl | Covered 100% for the life of the liner |
Why people buy their liner at Gordo's
- We quote in mil, not gauge. You'll always know the real wall and floor thickness before you pay.
- Authorized Doughboy dealer since 1956. Liners are sourced from the factory with the matching receivers, hardware, and warranty paperwork.
- We protect your pool warranty. A non-Doughboy liner voids the pool warranty, we make sure that does not happen by accident.
- Central Valley measurements done right. We confirm shape, wall height, attachment style, and bottom type so the liner fits the first time.
- Local support after the sale. A real phone number, a real store at 6167 Yosemite Blvd, and trusted installer referrals.
Pro tip from our liner desk: if a competitor will not give you the actual mil thickness of the wall and the floor in writing, assume the floor is thinner than the wall. Then compare that number, not the gauge, to a true 20 mil or 25 mil Doughboy liner.
Made in America for over 75 years
American-Made, Backed By A 1956 Modesto Dealer
Doughboy has been an American manufacturer since 1947, with roots that trace back to the World War I sealing techniques used to package rations for the American "Doughboys." Every pool, liner, and component is engineered and built in the United States, supporting American jobs and backed locally by Gordo's Pool City since 1956.
Customer Reviews
What Central Valley pool owners say about Gordo's
Verified Google reviews from neighbors who trust Gordo's Pool City with their liners, equipment, and water chemistry.
4.2 on Google · 82+ reviewsPaul Smith
Modesto, CA · Jan 2023
Google Review“I have known John for quite some time now. He is the “pool guy.” He and his staff know their stuff about pools and pool care, as well as spas. As long as he is in business, he will have my business.”
Charles Morales
Modesto, CA · Jan 2024
Google Review“They are right there explaining step by step how to complete the work.”
Rebecca Lux
14-year customer · Jun 2019
Google Review“Gordo's has everything!!! Plus their clerks have the pool knowledge I needed. If they didn't know they'd turn you over to the owner or someone with more experience. It's the only place I'll go and feel at ease about what I'm buying. 14-year customer, I give you a 5 star ☆☆☆☆☆.”
Liner Quote
Request a OVERLAP Expandable Liners for your pool.
Pick the pattern you like and share your pool measurements. We'll confirm the right fit and the right hardware before you order.
Frequently asked questions
OVERLAP Expandable Liners, Frequently Asked Questions
Common questions about Doughboy overlap expandable liners, fit, warranty, and installation in the Central Valley.