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DIY basement waterproofing | SealOnce Basement System

$6 per ft

SealOnce Basement System is an easy to install, do-it-yourself basement waterproofing channel that permanently dries up wet, leaky basements. The hollow baseboard channel collects the seepage water and drains it away to either your basement floor drain or sump pump.


As Seen in This Old House, The New York Times, Family Handyman Magazine, Wall Street Journal and Basement Health Association

How To Order

Order you custom SealOnce Basement Waterproofing System based off your basement’s measurements.
If you have any questions or need help please call us at 651-644-2000.

Step 1: Measure Your Basement

You only need 3 quick measurements:
1. Total linear footage
2. Number of inside corners
3. Number of outside corners

*Here’s the quick way to measure linear footage*

Step 2: Order Your Kit

Divide your total linear footage amount by 4 to get the quantity of SealOnce Main Sections (4-foot lengths) you need. You need 1 tube of SealOnce Waterproofing Adhesive per main section for proper installation. 

  • SealOnce Basement System 4ft Main Section

    SealOnce Basement System: 4ft Main Section

  • SealOnce Adhesive | Basement Waterproofing Sealer

    SealOnce Waterproofing Adhesive (10oz)

  • SealOnce Basement System Inside Corner

    SealOnce Basement System: Inside Corner

  • SealOnce Basement System Outside Corner

    SealOnce Basement System: Outside Corner

  • SealOnce Basement System Butt Joints

    SealOnce Basement System: Butt Joints (5 Pack)

  • Water X-Tract Basement Waterproofing end cap

    SealOnce Basement System: End Cap

  • Basement Waterproofing Drain Port

    SealOnce Basement System: Drain Port (23in)

  • Perfect Seal Tool Kit - DIY basement waterproofing tools

    Perfect SealOnce Tool Kit

  • Wire drill attachment to strip paint from concrete

    SealOnce Roto-Stripper Drill Attachment for Paint Removal

Perfect Seal Tool Kit - DIY basement waterproofing tools
SB66-6Perfect SealOnce Tool KitCustom tool kit for a water-tight installation. You need 1 per order.$9.85
Wire drill attachment to strip paint from concrete
SB-ROTOSealOnce Roto-Stripper Drill Attachment for Paint RemovalRoto-Stripper quickly removes paint, varnish, rust and corrosion from surfaces including concrete floors. Used to remove paint and adhesives …$24.95

How It Works

Waterproof your basement permanently for less than $1,000 – and it only takes a weekend!

SealOnce Basement System is ideal for basements that leak water through the joint were the floor and walls meet. When soil around your foundation becomes water-saturated, hydrostatic pressure forces water up through the joint where your floor and walls meet. The SealOnce Basement System can cure that problem without busting up your floor.

DIY basement waterproofing system

SealOnce Basement System is ideal for basements that leak water through the joint where the floor and walls meet

One of the most common DIY mistakes homeowner’s make when trying to fix a basement leak is using products that attempt to stop, plug or hold back water. A professional waterproofing contractor would never use these type of bandaid products. Instead, they will tap into the source of the water to relieve the hydrostaic pressure and properly drain away the water. This is exactly what the SealOnce Basement System does, giving homeowner’s the opportunity to dry up their basement like a PRO would!

✔  No busting up your basement floor
✔  Easy do-it-yourself installation (we’ll walk you through every step!)
✔  40+ years of proven success
✔  Permanent system to a wet basement
✔  Our exclusive SealOnce Adhesive bonds watertight in wet or dry conditions

SealOnce Basement System is a hollow baseboard waterproofing channel that collects seeping water and drains it away.

No busting up your basement floor or need to excavate around your foundation to fix your wet basement with our system. SealOnce Basement System is permanent fix to your wet basement. Create your custom kit based on your basement’s measurements.

4-foot Main Sections

Main sections are adhered to the basement floor using our SealOnce Waterproofing Adhesive. Made of PVC and come in 4-foot lengths. 

SealOnce Adhesive

Our exclusive waterproofing sealant bonds main sections and components water-tight in wet or dry conditions! You need one tube of adhesive per main section for installation.

Inside Corner

Pre-molded 90-degree inside corners make for a clean, easy and professionally-finished installation. No need to miter corners like other systems.

Outside Corner

Pre-molded 90-degree outside corners to follow along any bump outs or unique shaped basements.

Butt Joints

Connects main sections end-to-end with an overlapping joint. Butt-joints are sealed water-tight with our adhesive. Come in packs of 5 butt-joints.

End Cap

End caps are universal and used to dead-end the system.

Drain Port

23-inch drain port connects the face of the main section and tee’s off to a sump pump or floor drain to drain the water from the channel.

New! SealOnce Tool Kit

Our custom bullnose tool slicks down the water-tight seal leaving the proper amount of adhesive to create a lasting water-tight seal without needing to use your fingers to slick down adhesive. Follow with square-nose tool for quick and easy clean up.


SealOnce Main Section Dimensions:

TALL: 4-1/4″

COLOR: Beige
(You could paint the system with a flat latex paint if desired.)


SealOnce Adhesive:

New & improved 3rd generation waterproofing sealant! Bonds in wet or dry condition!
SIZE: Standard 10oz. Caulking Tubes
COLOR: Beige


SealOnce Basement System is an easy weekend project. No special tools or skills required. Drying up your wet basement is easier than ever with our NEW Perfect SealOnce Tools. Installation is easy and mess-free! With every order you’ll get the full installation guide walking you through step-by-step how to install the DIY basement waterproofing system. If you have any questions during your install we’re here to help. Just give us a call at 651-644-2000 for quick support.

Relieve Hydrostatic Pressure
(Block Walls Only)

If you have a block wall foundation you’ll start by relieving the hydrostatic pressure by drilling 1/2” to 5/8” weep holes into the hollow cells (4” to 6” in from each mortar joint) of your block walls at the point where the floor and wall meet. Solid poured concrete, brick and stone walls have no hollow cavities, therefore, you don’t drill weep holes.

Clean Floor Properly

Sweep the concrete floor clean. Next, clean the bare concrete floor by washing the surface with clean water and a sponge to remove all dirt and dust.

Layout System

Cut and trial fit the main sections along the basement walls. Place inside and outside corners where needed. Use a tin snips, hacksaw or miter saw to cut the main sections as needed.

Bond Sections to the Concrete

The bottom bead of adhesive is your system’s structural bond to the concrete floor. Start by turning the main section over and apply a tall, thick bead of adhesive (about the size of your thumb) to the bottom of the main section.

Install Pre-Molded Corners

Apply SealOnce Adhesive on both main sections. Inside corners are easy to install when dropped down from the top. Seal the corner’s edges and caulk the bottom for a watertight bond.

Install Butt-Joints

To install the butt-joints between main sections apply SealOnce Adhesive on both ends of the adjoining main sections. Hook the butt-joint at the bottom and snap over top. Finish by sealing the edges with the SealOnce Adhesive for a water-tight seal.

Apply Finishing Seal

Caulk the floor joint with enough pressure to force some SealOnce Adhesive under the system. Immediately follow to next step…

Seal the System Water-tight

Slick down the finishing bead of adhesive our NEW Perfect SealOnce Bullnose Tool. Holding the tool in this position slowly drag it all the way down the system leaving a perfect seal. The finishing seal is your water-tight seal of your system.

Drain the System

You can drain your SealOnce Basement System to a sump pump or floor drain using our Drain Port channel. Drain Ports come in 23″ lengths that can easily be cut down to size. Set the drain port in place and trace along the outside. Using a tinsnips, cut out the opening in the main section. Glue the drain port to the floor and seal the joint between drain port and main section with SealOnce Adhesive.


SealOnce basement waterproofing beaver baseboard system

The most common mistake do-it-yourself homeowners make when waterproofing their basement is trying to push or stop the water with paints or patch-its. Waterproofing paints or membranes are hugely labor intensive and never last longterm. To permanently dry up your wet basement you need to think like the PROs! The SealOnce Basement System is the ideal do-it-yourself remedy to a wet basement because it relieves hydrostatic pressure and properly drains and collects water seepage just like the PRO’s without the big price tag!

As the soil around your foundation becomes water-saturated, hydrostatic pressure forces water through the joint where your floor and wall meet. SealOnce Basement System can cure that problem. Designed as a hollow baseboard, this easy to install DIY basement waterproofing channel collects the seeping water and quietly drains it to your floor drain or sump pump.

The only skill needed for installation is the ability to follow directions. Just seal the pre-molded corners and easy to handle main sections to the floor using the SealOnce Adhesive. With the SealOnce Basement System in place, walls can easily be paneled or finished. Drying up your wet basement is the first step towards a clean and healthy room ready for living, storage, and play. The SealOnce Basement System can turn your wet basement into a comfortable room suitable for your home and family.


Millions of feet installed across the US and Canada since 1965. From the Hoover Dam, Fort Knox, US Embassy, Mercer County Housing, Minnesota Historical Society and several colleges and universities across the United States.

Have not had a drop of water on the floor since and we can once againuse the room to store things without worry of water damage. I was so impressed that I installed it in the other areas of the basement. I’m a woman and I did all this with NO help – very easy!

Peggy Yehl

I did the basement of my fiance’s (now wife) house in Madison, WI 3 years ago before she sold it to move in with me. It was a mid-50’s house on a small lot. The surrounding neighbor’s yards all were of higher elevation and flowed into her yard.

One neighbors house was merely 10′ away and both rooflines dumped into this narrow breezeway. This was also the only avenue of escape for all of the water in the backyard. She often joked about her “water feature” which was located in the basement.

Over the course of 12 years she spent 1000’s of dollars on gutters and landscaping, including hiring a landscape architect who installed many deep-rooted plants and even a French drain. Even with all of this she still had problems. Being a contractor I knew that there had to be something I could do, and after much research I found this amazing product.

It was easy to order, easy to install and has worked amazingly!! Drying up the basement allowed me to fix all of the ruined drywall, lay new carpet and flooring, and reclaim the basement as usable space in a tiny 750 square foot home. Directions are very simple and the average do-it-yourselfer could perform it themselves.

Bart Bartos

I installed this system in my finished basement in spring of 2016 after the rainy season. It was tested last weekend during the record rainfall in MO. The system worked flawlessly.

James Meeks

Nice quick and easy – anyone can do it and best of all save a lot of money!!

Mark Mullet

Thought you might like to see how your system turned out for us on a rental house we own. We had water all the time in this basement and decided to tackle the issue ourselves. We are seniors and found it to be very easy to do. Instructions were great. We had to work in a lot of water and that did make the job more difficult but with your system and another product to repair the cracks in the floor and then coat the entire floor we now have a dry basement. The total transformation is incredible. I am glad that we researched and found your system. Thanks for a great product for the do it yourselfers.

Ken & Patty Merritt



For many homeowners the SealOnce Basement System is the first time they’ve had access to a professional-grade basement water control system they can install themselves and often have a few questions. Below are answers to the most common questions first time homewoners ask.

How will water flow if my floor is uneven?

SealOnce Basement System stands 4-inches tall to allow for uneven floors. As water around your foundation rises, it begins to flow into the channel. Water flows naturally toward any low spot or drain.

Will water remain standing in low areas of my SealOnce Basement System?

When the water stops flowing out the drain or sump pump, you know that the SealOnce Basment System has finished its work. With the water level now lower than the floor, any water left standing in the channel flows back out through the weep holes or joint where the floor and walls meet for poured foundations.

Will the SealOnce Basement System require maintenance?

The SealOnce Basement System is made of PVC, the same as the water pipes in your home. An attribute to PVC is that it will not support algea that causes odors. The SealOnce Basement System itself needs no maintenance.

How long will the SealOnce Basement System last?

The SealOnce Basement System is a permanent installation. Systems installed in 1965 are working today, just the way they did when originally installed.

Why do I need to drill weep holes?

Hydrostatic pressure is relieved in block wall foundations by drilling weep holes in the concrete block cavities at floor level. The hollow DIY basement waterproofing channel collects the seepage. The baseboard is not attached to the wall, it allows air to circulate within the block cavities to help keep them dry. It also provides a source of disposal for upper-wall moisture to enter the channel.

How will the SealOnce Basement System work with poured concrete, brick or stone walls?

SealOnce Basement System works with any type of basement wall because the main sections are not glued to the walls. They simply rest against the face of basement walls. The top of the system is left open to allow any water seepage from the face of the walls to enter the system. The top the main section curls back creating a mini-trough directing the water behind and into the channel.

Can I finish my basement after installing the SealOnce Basement System?

Absolutely! You can easily box out and frame around the SealOnce Basement System, install drywall and other finishings in your new basement.

I have a floating slab basement, will the SealOnce Basement System work for me?

Yes, the SealOnce Basement System can be installed in a basement with a floating slab. Depending on the width of the trench around the basement you can either install the system in the trench (This would require the bottom of the trench to have a concrete surface. It can not be installed over dirt or sand.) or you would install the system on the floor out in front of the trench. The top of the system would not rest against the wall in this situation. An optional step when installing the system out in front of the trench on the concrete basement floor, would be to anchor a green-treated 2×2 board horizontally to the wall around the perimeter of the basement at the height of the top of the SealOnce Main Section. The SealOnce Main Sections are 4-1/4″ tall, therefore, you’d want the center of your horizontal 2×2 installed about 4-1/4″ up from the surface of the concrete floor.

Still have questions?
Call us. We’re here to help.

(651) 644-2000