What are Basement Engineering Tabs?

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Engineering tabs are a powerful addition to any interior basement waterproofing installation. It works like having ten people lift and move a car instead of one. The tabs stabilize your foundation by keeping your concrete slab up against your basement walls. We will explain below.

What Are Engineering Tabs?

Engineering tabs keep your foundation’s original structural integrity intact. That means parts of your slab floor will stay on the footing and up against your walls. A trench is dug out around the perimeter of the basement, including underneath each tab. Basement waterproofing pipe and stone are placed in the trench and follow the same path.

Engineering tabs above basement waterproofing drainage
Engineering tabs maintain engineering principles to keep a foundation strong.

Engineers design your basement’s structure to serve an essential purpose. They take three vital parts, the footer, wall, and floor, and connect them to support one another.

The footer holds the walls up, while the floor sits on the footer for support and holds the walls out. The floor is more critical than holding you up to walk on it. It reduces the impact of stress produced by hydrostatic pressure. The groundwater surrounding the outside of your basement creates this hydrostatic pressure. It gets very dense and increases in weight after heavy rain. All that soil and water pushes against your basement walls.

Customization is imperative in every basement waterproofing installation to solve a water problem. Engineering tabs are part of a customization process. They can vary in size and quantity depending on the basement’s size and the floor’s condition. Imagine a floor with no cracks and a 30+ foot wall length with three 24×20 inch floor tabs spaced apart. The installation crew will jackhammer engineering tabs in the floor along the remaining walls. All those tabs will be vital for supporting the wall. The tabs also will be able to rest on the footing to support the floor itself.

Interior Basement Drainage Pipe

Engineering tabs allow trenching and drainage pipes to run underneath without compromise. It takes more work; that is why many contractors don’t offer engineering tabs. More time on the clock means less money; for the customer, that means less value. The foundation is at risk of movement from a lack of support.

Drain Board Installation

Only a dimple drain board can be used with engineering tabs to get an effective waterproofing solution. The drain board is custom-cut to lie across the footer and against the wall. A skilled contractor will make a 1/2 to a 1-inch deep notch between the wall and floor across the engineering tab. Next, the drain board is custom-cut to rest inside the notch. Water rarely, if ever, seeps out of the notch, and if it does, it runs down the drain board gaps and into the system. Water seeks the path of least resistance, so it will always pick the area below the floor first.

Replacing Slab With Poured Concrete

Engineering Tabs are only part of the equation. Sections of the floor were removed to install the basement system. The contractor will replace the missing floor with poured concrete. There should be enough concrete to match the thickness of the original floor. You will find most slabs to be 3.5 to 4 inches in thickness. This is a building code requirement. Even so, the type of concrete mix is vital in improving the foundation’s strength.

Supercrete mends to an old concrete basement slab.
Supercrete mends to the original concrete slab and is applied at a code-compliant thickness.

Sometimes plain old concrete will not suffice, but one that mends, waterproofs, and increases strength will do wonders. American Dry Basement Systems uses two proprietary concrete mixes called Supercrete and Superslurry. They both have a crystalline ingredient that grows into older concrete. The concrete binds to the engineering tabs and the main body of the floor at a microscopic level. It grows continuously, making the foundation more robust and waterproof.

There are other crystalline formulas on the market, but Supercrete and Superslurry have been field-tested for two decades. They work perfectly for interior building use. Both are explicitly developed for basement and crawl space waterproofing.

There is a chance that the home already has a basement drainage system. One that clogs or is not good enough to handle the hydrostatic pressure. In that case, the previous contractors may have removed the floor from the perimeter footer to install their drainage and replaced it with plain concrete.

There are two methods for getting a foundation’s stability back.

  1. Supercrete: A proprietary crystalline mixture mends new concrete to the original concrete. This concrete mixture without engineering tabs will make the floor whole, but the process will take longer. In 24 hours, it is dry to the touch, and in 7 to 10 days mostly cured and will not crack.
  2. Mechanical Spacers: These are rebar reinforcement placed where an engineering tab should be. A masonry drill makes holes in the floor’s side to hold the rebar in place. The other half of the rebar rests on top of the footer, followed by the drainboard, vapor barrier, and concrete mix.
Mechanical spacers can help with additional floor support when floor is weak along the footer.


Suppose you find yourself in a situation where you need a basement waterproofing solution. You want to keep your basement dry but are equally concerned about the structural integrity of your foundation.

Give American Dry Basement Systems a call. We will put your mind at ease with a no-obligation inspection and estimate.