Build Your Own 20'' Septic Tank Riser Kit
1 Choose A 20'' Adapter Ring
The first component that you need in order to build a complete riser system is the adapter ring. The adapter ring mounts directly to the septic tank, allowing the risers to stack, lock, and mount to it.
Only ONE of the two options below is required!
- Best Seller
Polylok Square Tank Adapter Ring The Polylok Square Tank Adapter Ring accepts either 20'' or 24'' risers. The large squared shape of this adapter allows it to cover up to 25'' x 25'' square openings or up to 27'' in diameter round openings. It is recommended to mount this adapter ring to the tank using our Adapter Ring Installation Kit (#ANCHORKIT). Once mounted and sealed to the tank, any combination of Polylok risers and lids will attached directly to this adapter. READ MOREItem #:3009-AR
Product VideoOur Price: $85.00MSRP: $99.00 
Polylok 20" Round Tank Adapter RingThis Polylok Round Tank Adapter Ring is for 20'' round or smaller openings. This ring allows you to mount the Polylok risers to a concrete or plastic septic tank. This may also be used to convert other brands of risers to the Polylok system. Once the adapter ring is mounted and seals, any combination of Polylok 20'' diameter risers or lids will attach directly to this ring.
READ MOREItem #:3009-RTR20
Product VideoOur Price: $46.50MSRP: $55.00
2 Choose A 20'' Septic Tank Riser
Risers are used to bring the access of your septic tank to grade. Choose any combination of the options below to achieve the necessary rise. The Polylok risers are stackable.
Polylok 20" x 6" Septic Tank RiserThe Polylok 20" x 6" Septic Tank Riser (Model 3009) is a reliable, stackable extension designed to bring septic tank, distribution box, or catch basin access conveniently to ground level. This 6" tall riser provides flexible height adjustments for moderate burial depths, making inspections, pumping, and maintenance faster and easier without constant digging.
Constructed from durable high-density polyethylene (HDPE), it combines the strength of concrete-style risers with the lightweight benefits of plastic—resistant to shattering, frost adhesion, and long-term weathering.
POLYLOK RISERS NO LONGER COME WITH A FACTORY INSTALLED GASKET. We recommend using our butyl sealant tape to create a seal between risers.
READ MOREItem #:3009
Product VideoOur Price: $48.00MSRP: $59.00
Polylok 20" x 12" Septic Tank RiserThe Polylok 20" x 12" Septic Tank Riser (Model 3009-R12) is a tall, efficient extension riser that simplifies bringing septic tank or distribution box access to ground level with fewer sections. At 12" tall (1 foot), this riser reduces the number of connections and screws needed compared to stacking multiple shorter units—ideal for moderate to deeper burial depths while maintaining full stackability in the Polylok 20" series.
Crafted from rugged high-density polyethylene (HDPE), it delivers outstanding durability, UV resistance, and performance in demanding septic environments—outlasting brittle alternatives and easier to install than concrete.
POLYLOK RISERS NO LONGER COME WITH A FACTORY INSTALLED GASKET. We recommend using our butyl sealant tape to create a seal between risers.
READ MOREItem #:3009-R12
Product VideoOur Price: $82.00MSRP: $95.00
Polylok 20'' x 2'' Septic Tank RiserThe Polylok 20" x 2" Septic Tank Grade Riser (Model 3009-GR2) is the ideal low-profile extension for achieving precise, flush-to-grade septic tank or distribution box access. At just 2" tall, this slim grade riser is perfect for final height adjustments in the Build-a-20 Riser Kit system—when you need only a few inches to bring your lid perfectly level with the ground without excess protrusion or sunken appearance.
Built from tough high-density polyethylene (HDPE), it delivers the same trusted Polylok durability, UV resistance, and ease of use as taller sections, while remaining lightweight and simple to install.
The safety screen (#3009-SS) will not attach directly to this item.
POLYLOK RISERS NO LONGER COME WITH A FACTORY INSTALLED GASKET. We recommend using our butyl sealant tape to create a seal between risers.
READ MOREItem #:3009-GR2
Product VideoOur Price: $45.00MSRP: $59.00
3 Choose A 20'' Riser Lid
The final component that you will need to complete your riser system is a lid. The standard lid has handles for easy access, a factory installed gasket, and comes with stainless steel screws to lock in place. These lids can handle foot traffic or the weight of up to a riding lawn mower driving across them. The heavy duty lids are recommended for below grade installations or areas with high foot traffic.
Polylok 20" Septic Tank Riser LidThe Polylok 20" Septic Tank Riser Lid (Model PL-20RC / 3009-RC / 3009C) is the standard, reliable top cover for completing any Polylok 20" riser system. This durable lid seals your septic tank or distribution box access point securely at ground level, providing easy, tool-free access for pumping, inspections, and maintenance while blending into your landscape.
Manufactured from high-quality high-density polyethylene (HDPE) with the highest UV protection available, this lid resists fading, cracking, and degradation from sun exposure, ensuring long-term performance in outdoor conditions.
READ MOREItem #:3009-RC
Product VideoOur Price: $49.00MSRP: $59.00
Polylok 20" Heavy Duty Riser LidThe Polylok 20" Heavy Duty Riser Lid (Model 3017-C20) is the reinforced, flat-top cover engineered for demanding applications in your Polylok 20" riser or distribution box system. Unlike the standard lid with recessed handles, this heavy-duty version features a completely flat design with enhanced reinforcement—ideal for below-grade installations, high foot traffic areas, or locations subject to occasional light vehicle loads like riding lawn mowers or small garden tractors.
Constructed from durable high-density polyethylene (HDPE) with the highest UV protection available, this lid withstands harsh outdoor conditions, resisting fading, cracking, and degradation over time.
READ MOREItem #:3017-C20
Product VideoOur Price: $65.00MSRP: $75.00
4 Choose Optional 20'' Accessories
Below are optional but recommended accessories to include with your riser system.
Polylok 20" Septic Tank Riser Safety ScreenThe Polylok 20" Septic Tank Riser Safety Screen (Model 3009-SS) is an essential safety accessory that adds a critical secondary barrier to your Polylok 20" riser system. This bright yellow screen installs inside the top of the riser stack, preventing accidental entry into the septic tank if the riser lid is damaged, removed, or accidentally left off—providing vital protection for children, pets, and anyone near the access point.
Constructed from durable materials with a built-in handle for easy removal, this screen is engineered for visibility, strength, and reliable performance in residential septic setups.
The safety screen will not fit the 20''x3'' Pan Riser (#3009-LPRP) or the 20''x2'' Grade Riser (#3009-GR2).
READ MOREItem #:3009-SS
Product VideoOur Price: $34.50MSRP: $45.00- Best Seller
Adapter Installation Anchor Kit The adapter ring installation kit is used to mount and seal the Polylok tank adapter rings to a concrete tank. The kit includes concrete anchors, a masonry bit, and butyl sealant. READ MOREItem #:AnchorKit
Our Price: $25.00MSRP: $39.00 
Butyl Sealant RopeThe butyl sealant rope is used to seal the tank adapter ring to concrete, plastic, or fiberglass septic tanks. This can also be used as a sealant between riser sections that do not have an existing gasket.
24’’ Diameter Risers – Seal 3 Risers per 20ft Roll
20’’ Diameter Risers – Seal 4 Risers per 20ft Roll
12’’ Diameter Risers – Seal 6 Risers per 20ft Roll20ft Roll (1/2'' Wide, 1/4'' Thick)
READ MOREItem #:ASTM-C990
Our Price: $14.95MSRP: $19.95
THE POLYLOK SEPTIC TANK RISER ADVANTAGE
There are many different types and styles of septic tank risers on the market today. Our Polylok septic tank risers are simply the best your money can buy. The reasons are many, but here are the most important:
INTERNAL STRUCTURAL RIBS
The Polylok septic tank risers have structural ribs internally around each riser section which give them great strength and allow them to hold their shape with the pressure of soil being pushed against them once the hole is back filled. These internal structural ribs allow the outside of the riser to be smooth, this is important because of the freezing and thawing of the ground in many areas. When the ground freezes and thaws it expands and contracts and products with structural support on the outside of the riser can actually be lifted from the tank causing damage to the riser and the seal. The Polylok products will have no issues in frost areas because they are completely smooth on the outside!
LOW PROFILE RISER LIDS WITH HANDLES
The septic tank access lid on a riser system is one of the most important components, because it is what you see in your yard and also what you have to remove every time the system is pumped or maintained. The Polylok lids come with pre-installed handles that allow you to easily remove the lid any time you want to access the system. The lids are structurally supported on the bottom which also allows them to be relatively flat, instead of domed shaped like many other products on the market.
LARGE TANK ADAPTER RING
In order to put septic tank risers onto your septic tank, you need an adapter ring. Polylok has one of the largest adapter rings on the market allowing you to cover up to a 25’’ square opening or a 27’’ round opening. This ring accepts both 20’’ and 24’’ risers and gives you great flexibility no matter what size your opening may be.
SCREWS INCLUDED
At Septic Solutions we want to make your ordering and installation process as simple as possible. All of our Polylok Septic Tank Risers and Lids come complete with the screws necessary to install them.
