How to Waterproof Your Basement

SealOnce Basement System Installation Guide

SealOnce Basement System is easy to install. The only skilled needed is the ability to follow instructions. Included with your order will be our detailed installation guide to walk you through step-by-step how to dry up your wet basement like a PRO. We helped over 10,000 homeowners dry up their wet basement since 1965! Yours is next!

Tools Needed

  • Sponge, bucket and broom
  • Drill and 1/2″ or 5/8″ masonary drill bit
  • Tin snips or hacksaw to cut the main sections
  • Standard 10oz. caulking gun

Tips Before You Start…

  • One of the most important steps when installing the SealOnce Basement System is prepping your concrete floor. Be sure your floors are free of paint, dirt and residue.
  • SealOnce Adhesive is moisture activated and cures in wet conditions. Do note that you don’t want to install the system in standing water. You can install if the concrete is damp to the touch.
  • There is no need to prep your basement walls, as the top of the channel is not sealed to allow any seepage from the face (wall crack leak or window well overflowing) to be collected behind the system and carried to the drain outlet.
  • Weep holes are only needed with block wall foundations. If you have a poured, brick or stone wall do not drill weep holes.

If you have any questions when installing the system visit our frequently asked questions page or give on of our PRO’s a call at (651) 644-2000.

SealOnce Basement System Installation Guide

Included with every order of our do-it-yourself SealOnce Basement Waterproofing System is our easy to follow step-by-step installation guide!

Step 1: Relieve Hydrostatic Pressure

Drill 1/2″ or 5/8″ weep holes into the cells of each block (4″ to 6″ in from each mortar-joint) at the point where the floor and wall meet.

Tip → Solid poured concrete, brick and stone walls have no cavities, therefore you don’t drill weep holes.

Step 2: Prep Concrete Floor

This step is only necessary for concrete floors that have paint or left over tile or carpet adhesives. Use a metal paint stripper wheel with your electric drill to remove paint and adhesives from the floor 3″ out from the wall.

Do NOT use paint strippers or chemicals. You don’t need to prep the walls as the top of the system is left open to allow any seepage from the face of the wall to be collected behind the system.

Clean basement floor

Step 3: Clean Concrete Floor

Clean the bare concrete floor by washing with clear water and sponge to remove all dirt and dust. When finished feel the area with your fingers for any loose grit left behind.

Step 4: Cut & Fit Main Sections

Now you are ready to cut and trial fit the main sections along the basement walls.

Step 5: Placing Corners

Begin by placing per-molded corner sections in all the corners. Mark the floor in front of the corners showing where the main sections will stop.

Layout main sections

Step 6: Layout System

Place full sections end-to-end along the wall between the corners marked on the floor. Use a tin snips or hack saw to cut main sections as needed. Lay out the system just as it will be permanently installed. This is will make installation quick and easy.

SealOnce basement waterproofing sealant

Step 7: SealOnce Adhesive

Angle cut the tip just under the cone shaped end. This will give the large opening needed for applying SealOnce to all surfaces.

Tip → You need 1 tube of SealOnce is needed for each 4 feet, 6 inch main section.

Apply SealOnce waterproofing sealant

Step 8: Apply SealOnce Adhesive

Turn a main section over and apply a tall, thick bead of SealOnce to the bottom. Turn the main section back over and set in place. Press gently and hold in place for 30 seconds. Do NOT push down hard. This allows the SealOnce Adhesive to ooze down into the cement fines.

Step 9: Install Butt-Joints

Butt-joints make a seamless watertight connection at the critical joint between main sections. Apply SealOnce Adhesive on both sides of the seam. Hook the butt-joint at the bottom and “snap” in place at the top. Sealing the edges of the butt-joints and caulking the bottom will ensure a water-tight seal.

Install corners

Step 10: Install Pre-molded Corners

Install and seal our pre-molded inside and outside corners is easy. Inside corners are easy to install when dropped down from the top. Use a coarse sandpaper to rough up vinyl-to-vinyl surfaces. Apply SealOnce on both main sections and bottom of the corners. Seal the corner’s edges and caulk the bottom for a leak-free bond.

Tip → Unlike other systems, NO mitering corner joints with the SealOnce System!

Apply waterproof seal

Step 11: Apply Finishing Seal

Working with one main section at a time, caulk the floor joint with enough pressure to force some of the SealOnce Adhesive under the system. Immediately follow to step 12…

Seal waterproofing finish bead

Step 12: Slick & Seal

As soon as you caulk each section, slick down the finishing bead of adhesive slowly using a cornering tool or your fingers.

Tip → When using your fingers, dip them in a little liquid dish soap to create a smooth and feathered finish.

Install end caps

Step 13: Install End Caps

End caps are used to dead end the system. Apply SealOnce Adhesive across the bottom, up the wall and down the edge of the baseboard. Set end cap in place and caulk all joining surfaces again.

Drain system to sump pump system

Step 14: Drain to System

You can drain your system into either a floor drain or sump pump. Be sure and check your local building codes before draining to a floor drain. Draining to a sump pump, in most communities, is the proper method of disposing of ground water. We carry a professional-grade do-it-yourself sump pump kit.

Using the Drain Port cut and fit the port to length. Next, notch out the bottom of the main section to fit the drain port. Glue the drain port to the floor and face of the main section using the SealOnce Adhesive. The water will travel under the drain port and free fall into your floor drain or into the top of your sump pump pit. If you have a solid sump cover, cut out a notch at the edge to allow the water to free fall into the pit.

Your basement can easily be finish after installing the SealOnce Basement System.