How To Fill The Gap Between Soil And Foundation?

Most homeowners know that excessive rains and flooding constitute a serious hazard to their houses and foundational stability. Gaps between the soil and your home's foundation are symptoms of a larger problem. How can we resolve this issue? Don't worry; we have compiled helpful information to help you solve this problem.

These are the primary things you need to do:

  • Bring water to the soil gradually.
  • Avoid putting soil around the foundation's perimeter.
  • Avoid excessive fertilizers and chemicals

Soil expands when it is moist and contracts significantly when it is dry. Large cracks and gaps can develop as a result of soil shrinkage. Read through this article to the end to learn the best course of action in this circumstance.

Waterproofing foundation bitumen and insulation with polystyrene foam boards for House Energy Saving. Damp proofing Coatings.Waterproofing house foundation with spray on tar., How To Fill The Gap Between Soil And Foundation?

Your Home's Stability

Frame structure at under construction site on rural landscape.

Your foundation's "base" is the soil it sits on, so moisture content is important as your home's long-term stability depends on it. Avoid ignoring cracks and openings because if you do, things will only get worse. 

If the soil has shrunk down due to the heat and dryness, the soil separates from the foundation. The following are some options for you to try before calling a professional:

Water The Soil

Narrow depth of field Sprinkler head sprinkles water on grass with bokeh background.

Watering your lawn daily will aid in rehydrating the soil gradually, but the soil may swell if it becomes overly saturated too rapidly. As a result, it's crucial to gradually rehydrate the soil rather than soaking it. Applying water directly into the gap could lead to water incursion into the basement, therefore avoid doing so.

Gaps are produced around the basement wall as clay or other fine-particle soils dry up and contract. More of the soil is exposed to airflow in this area, which enhances moisture removal. A breach that reaches the base of the wall may eventually allow air to flow along the basement wall, drying the soil beneath the foundation.

Use a soaker hose, a common drip watering hose used by gardeners, to do this. Small "pores" or holes run the length of a soaker hose. A soaker hose consumes less water than a typical sprinkler and decreases the water's evaporation.

Avoid Adding Soil

When some homeowners see gaps, they immediately assume that the vacant space needs to be filled with more soil. Since there is a space between the dirt and the basement wall, rainwater can run down the wall and enter the basement.

When proper moisture levels return, adding additional soil may increase pressure on your foundations. That fresh dirt expands as it becomes wet, and you might notice further problems with internal walls cracking.

Fertilizers And Chemicals

Stick to water instead of using excessive amounts of pesticides and fertilizers that could absorb too much moisture. If you decide to use these pesticides on your lawn, it is typically better to do so when the ground has thawed early in the following year.

Watering the remaining plants and trees in your yard will also assist with the dryness. They might have to search further for moisture because of the dry summer.

What Kind Of Materials Is Ideal For Foundation Backfill?

A solid and stable grade can only be made with a backfill. Backfill is used in construction to replace lost soil during the building process and to reinforce a structure's foundation. Various materials can be used, depending on the specifications for the backfill. 

You must choose the materials that will make the best backfill. If you backfill too fast, cracks could form in the structure, so make sure the foundation cures for a few days. Coarse-grained soil, soils with fine grains and moderate to medium plasticity, rocks, shale, and commercial by-products are some of the materials you can use in backfilling a foundation.

Backfilling not only gives the structure's foundation more support but also enables the foundation to become strong enough to sustain the weight of the superstructure, which improves a property's performance and durability even more.

Coarse-grained Soil

Sandy and gravelly soils with little to no fines are classified as coarse-grained. All of the properly graded soils in this group have decent qualities for compaction, and when sufficiently compacted, they offer strong backfill and foundation stability.

Gravel or sand-like soils make up coarse-grained soils, which can be identified by their rounded to angular grain sizes and sand-like texturewhen touched.

Close up sand for construction.

Soils With Fine Grains And Low Plasticity

This category includes inorganic silts, very fine sands of low plasticity, and organic clays of low to medium plasticity. The inorganic clays may be easily compacted with large compaction equipment to give an excellent, stable backfill because they are comparatively impermeable.

Therefore, be careful when using soils as backfill, especially below the groundwater level. Additionally, saturated ML soils are likely to liquefy under dynamic loading. Laboratory testing should be conducted to identify the potential for liquefaction of such soils before they are employed as backfill in seismically active locations.


The gradation and hardness of the rock particles have a significant impact on the effectiveness of rock as a backfill material.

Most subsurface structure locations only excavate a small amount of hard rock, however, some cohesionless materials may be hard to locate or expensive. Excavated hard rock can be designated for processing in crushers and used as the preferred cohesionless material.

Some places, where more material is needed to fill a larger hole, may opt to start with a 3" stone layer as the first layer of material. Large areas may be filled with a 3" stone, but some gaps may remain. However, it has great drainage properties.

stone pile and ground isolated on white background with clipping path


Although shale is sometimes referred to as rock, its propensity for breaking down under heavy compaction machinery's weight and slaking after installation when exposed to air or water calls for specific attention. Some soft shale materials degrade when subjected to powerful compaction machinery.

Before using this kind of material as a backfill, this fact needs to be understood. The contractor may need to build a test fill and experiment with the water content, lift thickness, and several coverages using the equipment to be used for the backfill operation to establish the right compaction requirements.

Flat stone shale closeup top view.

Marginal Materials

Marginal materials are those that would not typically be employed as backfill if better materials are available due to their weak compaction, consolidation, or swelling qualities. Expansive clays and fine-grained soils with great plasticity are examples of marginal materials.

Marginal materials should be used based on energy- and cost-saving needs. These measures should consider the price of obtaining suitable material from a nearby borrow area or commercial sources, potential distress repair costs, and the additional costs associated with processing, placing, and adequately compacting marginal material.

How Can I Keep The Foundation Of My House Dry?

If water is allowed to collect around your foundation, it can lead to many different issues. These problems -- leaks, degradation, and the like -- should be avoided. You can keep water away from the foundation of your house with:

  • Gutter installations
  • Downspout expansions
  • Sump pump usage
  • Lawn grading

Installing And Maintaining A Gutter System

Every house has a gutter system by default, but if for any reason yours doesn't, you should install one immediately. Rainwater from the roof is directed away from the house by gutter systems. For the water to flow effectively, gutters must be clear of leaves and other debris.

Adding Downspout Extensions

You can add downspout extensions if your gutter systems function but water still appears to collect at the bottom. Long, flexible tubes called downspout extensions can be attached at the end of your downspout. They'll aid in diverting water away from the foundation of your house.

Using Sump Pumps

A sump pump is essential if you're constructing a house with a basement. Water accumulated in the sump basin will be pumped away from your home by a sump pump.

Grading Your Yard

Yard grading changes your yard's grade from level to sloping. You'll probably decide to regrade your yard so it slopes away from your house to improve drainage. Water can run down and away from your foundation by sloping the yard away from your home. It's critical to remember that not every yard can be regraded.

In Closing

Don't ignore cracks and gaps since different types of soil expand and contract; if you do, the situation will only worsen. If you notice a gap between the soil and foundation you'll need to bring water to the soil gradually, avoid putting soil around the foundation's perimeter, and avoid excessive fertilizers and chemicals.

If you find this article informative, here are other related articles:

Gap Between Siding And Foundation – What To Do?

How And What To Plant Around House Foundation

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