Below Grade Waterproofing: Common Types & Materials

When it comes to the structure of any building, whether it’s a single-family home or a skyscraper or something in between, below grade waterproofing is an essential part of the construction process. At Thome Waterproofing, we can provide you with any type of below grade waterproofing you might need.

Why Is Below Grade Waterproofing Important?

Water damage can be one of the costliest issues for a homeowner or building owner to fix. If water can seep into the walls of a structure, this can cause issues such as mold or damage to the structural integrity of a building. Neither of these issues is easy or cheap to repair, which is why you need to hire someone to provide proper below grade waterproofing during the construction process.

Below grade waterproofing refers to the process of applying waterproofing materials to a structure below the ground level and this includes basements, subterranean garages, foundation waterproofing and crawlspace waterproofing, depending on what is being built below the grade. Waterproofing prevents runoff and groundwater from seeping into the subterranean structure of a building and causing damage.

As a side note, while proper below grade waterproofing is crucial, ensuring proper drainage around a building or home are crucial as well. There needs to be an easy way for water runoff from rains to flow away from a structure and not pool up near the foundation. Below grade waterproofing can protect a structure from water damage, but for an ultimate level of protection, there needs to be plenty of drainage, as well.

Types Of Below Grade Waterproofing

There is no one-size-fits-all method for below grade waterproofing. Not only are there different types of below grade waterproofing, but there are also many different types of waterproofing materials. Let’s take a look at the common options for below grade waterproofing.

  • Positive Side Waterproofing – This is applied to the exterior of your foundation and typically this is the ideal situation, as we prepare a watertight barrier between the below-grade structure and the soil that will be placed around it. Sheet membranes and fluid-applied membranes are two options with positive side waterproofing.
  • Negative Side Waterproofing – As the name suggests, this is the opposite of positive side waterproofing and for this, we apply waterproofing materials and coatings to the inside of the below-grade structure or slab. While this can prevent water damage, it is not as efficient as positive side waterproofing because water can still seep through the exterior of the slab or foundation.
  • Still, we have many excellent products that can protect your below-grade structures if you need negative side waterproofing and on the plus side, we can always access the waterproofed area easily after installation, which would be enormously difficult with positive side waterproofing.
  • Blindside Waterproofing – This type of waterproofing often is used in urban areas, where there may be limited access to the exterior walls. It provides a watertight barrier for the exterior walls without requiring an excessive amount of soil removal, which can be tricky on properties in densely developed areas.

Choosing Waterproofing Materials

When hiring a waterproofing company, it is important to select a business that has extensive experience with many different types of waterproofing products and has the ability to match the best possible waterproofing materials to your unique construction process. Experts from waterproofing companies have to consider the type of structure, the location and the type of soil where the foundation will be laid.

For instance, soil that contains a good portion of clay can be problematic for the foundation of a building as clay easily absorbs moisture and then begins to expand. This can cause your foundation to move and can cause structural issues. Typically, this is why you don’t find basements in homes where clay soil is common.

With clay, the builder needs to ensure that the soil is tightly compacted and that there is an abundance of drainage around the structure, so that water flows away from the home. Proper drainage is important with any type of soil, but especially with clay soils. At a waterproofing company, our piece of the construction puzzle with be using materials that can handle issues related to clay soil.

Sandy soils can be less problematic than clay soil because sand won’t soak up the water and expand. However, sandy soil can erode fairly easily, which can cause settlement issues. Sandy soil needs to be well compacted to handle the load of the structure being built upon it. While soil can be a good option for some foundations, waterproofing contractors still need to be called in to ensure that everything below the slab or grade is properly waterproofed.

For builds on bedrock or limestone, waterproofing also is still needed, but rock materials are very durable and have tremendous load-bearing capabilities. Loam is another type of soil that is a mix of sand, clay and silt, and it combines the beneficial properties of all of these materials, which makes it a good option for many building projects.

But again, even with loam or rock, waterproofing is still your best defense against foundation issues and water damage. Remember, water damage doesn’t just cause structural issues, it also is a breeding ground for mold and pests such as termites.

We are experienced with a wide range of below grade waterproofing materials and processes, including prefabricated membrane systems and fluid-applied membranes as well as drainage systems. For instance, we can use Ecodrain-E drainage boards or footer/strip drainage systems for some projects. Carlisle Coatings has a variety of products we can use including MiraDRI, root barriers and protecting fabrics.

At Thome Waterproofing, we also often use CETCO bentonite geotextile waterproofing composite as well as CETCO Cetseal, which is a multi-purpose, single-component polyether moisture cure sealant. We also are experienced with a variety of Aquafin coatings and barriers. These are just a few waterproofing products which might be a match for your below grade waterproofing project.

Need Waterproofing? Contact Thome Waterproofing Today!

No matter what type of soil or structure is being built, the team at Thome Waterproofing will select the ideal waterproofing materials and the best waterproofing method to ensure that your structure is protected for the long haul. We provide below grade waterproofing services for all types of residential and commercial building structures throughout the greater Los Angeles area. If you need waterproofing contractors, give us a call at any time to set up a free consultation.