Basement Waterproofing for New Homes

Single-family homes are classified as a attached or detached house.

Detached Homes

A detached home sits on its own lot and is not connected to, or share any walls with, the house on the lot beside it.

Attached Homes

An attached single-family home shares at least one wall with the home beside it. These are commonly townhouses, duplexes, or quadruplexes.

Waterproofing

Homes with a basement or any portion of the structure below grade, require basement waterproofing.

There are three main types of foundations used in single-family home construction: basement, crawl space, and slab-on-grade. Each type supports the home differently and affects how waterproofing is applied.

Most homes are built using poured concrete, ICF (Insulated Concrete Forms), concrete block, or masonry foundations.

Basement Foundations

A basement foundation extends below ground level and provides extra living or storage space. Because it sits below grade, it requires full waterproofing to protect against groundwater and soil moisture.

Crawl Space Foundations

A crawl space foundation raises the home slightly above ground level, leaving a small space between the soil and the floor above. It helps protect the home from moisture and provides access for plumbing and electrical systems.

Slab-on-Grade Foundations

A slab-on-grade foundation is a single layer of concrete poured directly on the ground. It is common in warmer climates or areas with high water tables where basements are not practical.

When building a below-grade foundation with a living space, there are a number of different building materials you can use. Some of the most common are:

• Poured Concrete
• Insulated Concrete Forms (ICF)
• Concrete Block / Concrete Masonry Units (CMUs)

Poured Concrete Foundations

Poured concrete is the most commonly used material for a foundation wall or slab on grade base. It provides a strong seamless base

How it’s constructed: Concrete forms are built to the shape of the foundation walls, reinforced with rebar, and then filled with concrete. Once the concrete cures, the forms are removed, leaving a solid wall ready for waterproofing and backfilling.

ICF, Insulated Concrete Forms

ICF foundations are growing in popularity. They several advantages compared to traditional concrete or block foundations. The biggest is the thermal efficiency. They combine the strength of concrete with the insulation of rigid foam. Their design makes them ideal for colder climates.

How they are constructed: ICF's are an Interlocking foam blocks. They're easily stacked together, like Lego, to the required shape of the foundation. Reinforcing steel is placed inside the hollow centers, which are then filled with concrete. The foam stays in place and provides permanent insulation on both sides of the wall.

Concrete Block (CMU)

Concrete block foundations are less common in new home construction but are still widely found in older homes and throughout the Southeastern and Mid-Atlantic United States.

How it’s constructed: Concrete blocks are laid in rows with mortar between each joint. The hollow cores can be filled with concrete or rebar for added strength. The surface is often coated or parged before waterproofing.

WATERPROOFING:
No matter what type of foundation is used to build a basement foundation, they all need waterproofing to protect against moisture and water.

No matter what type of foundation you have, it will always need waterproofing to protect against groundwater and moisture. There the two main products are waterproof coatings and dimpled membranes (drain boards).

Waterproof Coatings

Waterproof coatings are applied directly to the exterior foundation wall. They form a sealed barrier that prevents water from passing through the concrete or block surface. Once applied, a drainage layer is added to protect the coating before the foundation is backfilled. Coatings are commonly used on poured concrete and ICF foundations to stop moisture at the wall surface.

Dimpled Membranes

Dimpled membranes are installed over the waterproof coating to add a drainage layer and protect the wall. The raised dimples create a space for water to flow down to the footing drain instead of pushing against the foundation. This helps reduce hydrostatic pressure and protects the coating from damage during backfilling.