CRAWL SPACE FOUNDATION: Types, Cost, and How To Build It


You’ve heard the term “crawl space foundation,” but you’re not sure what it means or how it differs from a slab foundation. No big deal; it’s not a term that everyone is familiar with, so let me explain. This article will define a crawl space foundation, explain the two types, and how much they cost to repair. We will discuss how to build a crawl space foundation, as well as its advantages and disadvantages.

What is a Crawl Space Foundation?

A crawl space foundation is a foundation with concrete walls and a floor. The walls are at least 18 inches above ground level with access to this area after the house is set. The plumbing is usually installed in this area.
Crawl space foundations will have a flat slab of concrete but are built up with concrete walls and sometimes wooden walls as well as footers. They have enough space for someone to crawl through to fix problems underneath.

How Crawl Space Home Differ From Other Foundation Types

In colder climates, where the foundation must extend below the frost line, basement foundations are typically required. In warmer climates with no frost line to contend with, crawl space foundations are more common.

However, if it’s an older period home, crawl space foundations can be found anywhere because that was all they made at one time. Similar to a small unfinished basement, a crawl space foundation.

However, unlike basements, people do not use crawl spaces as living quarters. However, if crawl spaces are sealed, homeowners may use them for storage. The majority of crawl spaces are unsealed and should not be used for storage.

Two Types of Crawl Space Foundations

Crawl space foundations come in two varieties in our region of the United States and beyond:

  • Block and base, and
  • Pier and beam.

Homeowners are often more familiar with one term over the other, and some people combine both types of foundations and the term crawl space foundation into one term and use it interchangeably. Many people in our area simply refer to everything as a pier and beam foundation, even if it isn’t.

Pros and Cons of Crawl Space Foundation

Crawl space foundations, like most things, have benefits and drawbacks for both the homeowner and the builder. We’ll quickly break them down for you here:

Pros of Crawl Space Foundations

  • Simple access to home systems for repair, such as plumbing and electrical
  • Building an addition to a house may be simpler.
  • Foundation repair and house leveling costs are typically less expensive.
  • The house is built at a higher elevation for better yard views.
  • Wooden floor/foundation materials are gentler on the human body.

Cons of Crawl Space Foundations

  • Crawl space homes need ongoing maintenance
  • Compared to basement homes, under-home leaks are more likely to go undetected.
  • Lightweight and more prone to movement due to expansive soil and strong winds
  • A higher risk of drainage issues, mold/mildew, or musty odors
  • Some individuals believe they are outdated and inferior to other foundation types.
  • Unsuitable for cold, frosty climates or steeply sloping lots.

Crawl Space Foundation Repair 

There are several ways to solve crawl space problems, but you should always choose the most effective ones. Here are some viable solutions to some of these problems.

#1. Water drainage problems solved

When water accumulates beneath your home, you may need to install a sump pump to assist you in pumping the water out of your crawl space and into a location where it is needed. You can also consider raising the landscape around your home to prevent water from pooling. Gutters and downspouts can also greatly aid in water containment.

#2. Rodent and pest control solution

Rodents and other pests love to hide in your crawl space. The issue arises when these rodents and pests start to make their way into your home. They become a troubling nuisance

When you discover the presence of these pests, you must contact an exterminator to kill the rodents or pests before proceeding with the repair. To prevent future pest intrusion, you should make sure the crawl space has been sealed when performing repairs.

#3. Solution for moisture problems

To solve moisture issues in your crawl space, you can use vapor barriers or encapsulation. If you want to deal with moisture from the damp earth, you can use a vapor barrier. Encapsulation, on the other hand, protects your home from outside humidity as well.

Encapsulation is a better option for solving moisture-related problems. An ideal encapsulation process involves using specialized insulation, heavy polyethylene liners, and special dehumidifiers.

#4. Solution for insulation problems

If your insulation is missing or damaged, you have several options, including fiberglass insulation, rigid foam board insulation, and spray foam insulation. We recommend you do NOT use spray foam insulation.

When winter approaches, you may need to check your water pipes down there to ensure they are not in freezing conditions. Avoid open foundation vents to prevent pipes from freezing when the temperatures are coldest.

Crawl Space Foundation Repair Cost

Crawl space foundation repairs can be expensive, but the cost of the repair usually increases the longer it takes to address the issue. The longer a problem goes untreated, the worse it tends to become over time. That’s why it’s important to deal with any crawl space problems as soon as you know they exist.

Crawl space foundation repair typically costs around $6,000 to complete. However, several factors will determine the actual cost you pay. Between $1,500 and $15,000 is the typical repair cost range. The type of service you require and the extent of the damage will have a significant impact on the cost of repair. This post will look at some of the more common reasons you might need repairs, as well as the potential cost associated with these issues.

#1. Foundation repairs

When a house settles or sinks, foundation damage can occur. This is common when the dirt on which the house is built can no longer support the weight of the structure. Poor drainage, which allows rain and moisture to seep into the soil beneath your house, and plumbing leaks, which can also contribute to moisture issues, are additional causes of foundation damage.

When a house sinks or settles, cracks can appear as the foundation shifts to different levels, necessitating re-leveling. As with the house sinks, supports are susceptible to damage. If this occurs, they will need to be strengthened or replaced.

Depending on the issues that need to be fixed, foundation repairs typically cost between $2,000 and $7,000. Mud jacking, which can cost between $500 and $1,500, is typically required when re-leveling a house. Repairing damaged beams or supports will typically cost $1,000 to $3,000 per unit.

#2. Weather-related crawl space repairs

Bad weather can also increase the cost of repair. Mold can grow in the crawl space and up into the floors and walls of your home if there is too much moisture from rain or flooding. Water can also damage walls or beams, which may require replacement. Drought and extreme winter weather can also be damaging. Drought can deplete soil moisture, contributing to settling issues, while extreme winter weather can damage pipes, exacerbating moisture issues.

Extreme flooding can cost $9,000 or more to repair, but on average it can cost between $1,200 and $4,500 to clean and repair water damage. If you need to repair walls or beams, the cost is typically around $2,000, depending on the extent of the damage. Measures to prevent water and weather-related damage, such as encapsulation or waterproofing, can cost up to $15,000 or more.

#3. Crawl space cleaning

Cleaning can be a preventative measure, but it can also be considered a repair if mold, fungi, or pests are causing damage. If left untreated, mold can cause serious health problems. Fungi such as mushrooms, slime, and white mold are less harmful to your health, but they can still cause harm over time. Pests such as rats and termites are not only a nuisance when they invade a home, but they can also cause structural damage.

Depending on the extent of the problem and the size of the space, mold, and fungi removal typically cost between $1,000 and $3,500. Pest removal typically costs between $200 and $500, but a full removal, cleaning, and sealing to prevent future pest problems can cost between $2,000 and $4,000.

How to Build a Crawl Space Foundation

Crawl spaces are created when foundation walls are too short to support a basement. Depending on the build codes in your community, a crawlspace can be a few feet or many feet high. Even though you’re not pouring an entire basement, building a crawlspace foundation requires similar steps. Local building codes govern the placement of your foundation on the lot, its elevation, and your construction methods.

#1. Excavating the foundation

Although shovels could be used, nearly all foundations today benefit from front-end loader and backhoe excavation. The excavation contractor will dig the main foundation hole after staking out the perimeter of the building. He will dig trenches for the footings at the bottom of the hole. To prevent foundation wall shifting caused by soil expansion and contraction as moisture within the soil freezes and thaws, the depth of the crawlspace footings must be below the frost line for your geographical region.

#2. Pouring the footings

Crawlspace walls require concrete footings that disperse the house’s weight load into the ground. Footings are built on virgin soil, so trenches are dug only to the depth of the footing and no deeper. The soil beneath must be left alone. The amount of steel reinforcement required in the footings will be determined by building codes. While the concrete in the footing forms is still wet, rebar poles will be inserted into the footings. These poles provide vertical reinforcement, connecting the crawlspace walls to the footings.

#3. Building the walls

Once the footings are in place, the wall forms can be built. The thickness of the walls and the amount of steel reinforcement are governed by local build codes. Steel reinforcement is typically comprised of vertical rebar poles intersected by horizontal rebar poles and joined with rebar ties. Before you can pour the walls, the local build inspector will want to inspect the project to ensure that you added enough steel and that your forms are strong enough to support the weight of the wet concrete.

#4. Pouring the crawlspace walls

The walls should be poured in one continuous pour. Once you start dumping the concrete, keep going until all of the wall forms are full. This prevents cold joints that can occur when only a portion of a wall is poured and the concrete hardens before adding more. If you order more than one concrete truck, the concrete company will ensure that any additional trucks required are ready to pour as soon as the previous truck is empty.

#5. Anchor bolts and vibration

While the concrete in the forms is still wet, at least one worker should use a concrete vibrator to remove air bubbles that will weaken the concrete. To settle the concrete, a worker can tap on the inside and outside of the concrete forms with a rubber mallet. When the concrete begins to thicken, insert anchor bolts into the top of the wall, leaving about 3 inches of the bolt above the concrete level. The anchor bolts will secure the sill plate to the top of the crawlspace wall when you’re ready to frame the house.

Is a crawl space foundation good?

Yes. Because there is less digging for walls, a crawl space foundation is a better choice for sloped or low-grade lots. Furthermore, the foundation can be designed to level the flooring of the house.

How long does a crawl space foundation last?

With proper maintenance and regular inspections, both slab and crawl space foundations can last well beyond 50 years.

What are the disadvantages of a crawl space foundation?

Crawl spaces can be difficult to adequately insulate. In humid areas, poor insulation can lead to mold and rodent problems. Crawl-space foundations cannot compete with slab foundations in terms of energy cost. A home with a crawl space foundation is significantly more expensive to heat and cool.

What is the strongest foundation for a house?

Poured concrete is the strongest type of house foundation. Concrete is extremely strong and long-lasting, and it can be poured into any shape.

How deep should a crawl space foundation be?

This is perhaps the most obvious difference between the two spaces, with crawl spaces ranging from 18 in-6 ft (the majority being around 3 feet tall) and basements ranging from 8-10 ft.


When it comes to earthquakes, crawl space foundations outperform slab foundations by a wide margin. Crawl space foundations are earthquake resistant.

An earthquake’s lateral movements and general undulations make cracks easy to form. Crawl space foundation homes are elevated a few feet above the ground. A footing is poured, similar to a slab, and then blocks are laid to form the foundation that will support the structure’s walls.

Building a crawl space foundation will save you more money than a basement foundation, but not necessarily time, as they take longer to build.


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