A homeowner who wants to add square footage to his property may decide on converting a crawl space to a basement.
To do this, can you dig out a crawl space? It’s something you can certainly do but requires careful planning and execution.
For a more comprehensive picture, here’s everything you need to know when digging out a crawl space.
Can I Dig My Crawl Space Lower?
The usual approach for a crawlspace-to-basement conversion is by digging through raw earth. You’ll need to remove loads of soil to achieve the preferred height clearance.
Generally, you’re looking to make the typical eight feet requirement for any room. However, how deep you can dig, or if it’s possible at all, depends on several things.
Consult a Contractor or Structural Engineer
For starters, your home’s foundation should be in good condition.
If you observe cracks in walls and sagging floors, take a step back and think about your options. Renovations may do more damage and cost you a lot in the end.
This is why an expert’s opinion is beneficial during this stage. You can hire an experienced contractor or a structural engineer to conduct a thorough inspection.
They should be able to tell you about issues you may encounter and advise if you can push through with the project.
Soil testing may also be necessary. The results will help determine if the ground can bear the additional load of your basement.
Do Necessary Preparations
If conversion of your crawl space seems possible, you can proceed with the preparations before the actual digging begins.
1 – Decide Who’ll Take on the Job
The first thing to do is decide who’ll take on the job.
Naturally, a contractor is your best option. The process will run more smoothly because of their familiarity and experience with the task.
However, this can cost you around five to six figures, depending on the size of your space. Charges are usually on a per square footage basis.
For this reason, some homeowners decide to dig by hand and use their resources.
2 – Prepare the Materials
If you’re planning on DIY, take initial measurements of your crawlspace. This way, you’ll know what materials to prepare and how to get them inside.
In this regard, you’ll need a shovel for digging and a wheelbarrow or other hauling equipment to transport soil.
Be ready, as well, with support beams and concrete for creating foundations.
3 – Know the Risks
Structural faults may surface while you’re digging, or long after you complete the project.
You should watch out for foundation and moisture issues. Then, inform your contractor of any observations if you hired one.
4 – Acquire Applicable Permit
Digging through your crawl space may require a permit. So, always check local regulations before doing related activities.
How to Dig Out a Crawl Space
Whether hiring a building crew or digging the crawl space on your own, the steps are basically the same.
Here’s how to proceed with the task:
1 – Create a Support Structure
The stability of your home may suffer once you start digging. So, creating a support structure is an essential first step.
Using a shovel, gradually remove dirt at the center of your crawl space. Then, make your way outwards aiming for the support posts.
When you hit a post, focus on digging to the depth you want. Next to it, dig a hole four inches lower than your desired basement floor.
Repeat the same process next to other posts.
Upon completion, fill the holes with concrete and allow them to dry. That usually takes 48 hours.
Once the concrete cures, place a steel support beam on each plate. Opting for an adjustable steel post is highly recommended for this, in case you’ll need to make modifications.
You can also use wooden planks or beams to brace load-bearing walls.
2 – Dig the Rest of the Crawl Space
After installing support beams, continue excavating the rest of your crawl space.
Dig the soil down to the footings. Just remember to avoid hitting pipes or electrical wires.
Contractors may hasten this process by using mini excavators and other hauling mechanisms.
3 – Lay Down a New Foundation
You’ll need to lay a new foundation for your basement. That’s equivalent to around four to six feet of additional concrete walls, depending on the existing crawl space height.
Constructing new footings is on your list as well.
To do so, dig out the edges of your basement—but stay at least 2 feet away from the walls for safety purposes.
If you get too close, the dirt will begin to crumble and the walls may collapse outwards. In such cases, you’ll need additional support structures.
For extra caution, never excavate directly below the original footing. The soil in this area needs to stay intact to retain your home’s structural integrity.
Moreover, the new foundation should flow nicely with the old one. A weak connection between the two sets up your property for water issues and structural damage.
That said, you’ll need to drill holes in the old footing before pouring a new one. Then, insert steel reinforcement rods into these holes to tie the foundations together.
When the new footing hardens, pour concrete walls over the steel rods. This reduces shifting and strengthens the foundation.
4 – Install Drainage System
A basement is prone to water issues because of its below-grade location. To avoid flooding troubles in the future, set up a proper drainage system before adding the finishing touches to your space.
Take into consideration the landscapes around your home, too. If you’re on an elevated level, then a gravity drain may work.
Although in most cases, a sump pump may be necessary to draw out the water in the area.
5 – Pour in the Concrete Slab
The next step in your conversion project is pouring the concrete slab. This stage is critical since the flooring will hold the weight of your home and shouldn’t slide out or crack.
Level the concrete with the footing or just above it. Then, you’ll have to wait for the concrete to cure.
The flooring can take several weeks before it completely sets. Take note that the time will depend on the type of concrete used.
6 – Set Your Home into the New Foundation
Finally, set your home on the new foundation. That means removing unnecessary support assemblies and ensuring the load is evenly balanced across the foundation.
Be on the lookout for any structural issues from the get-go to a few months after construction.
Raise your concerns to the contractor if you hired one or seek advice if you did a DIY.
Final Thoughts
Can you dig out a crawl space? This undertaking is possible but entails risks.
Major considerations include the quality of the soil your house is built upon and the structural integrity of your property.
Digging out a crawl space is also expensive and time-consuming. You’ll need to hire a contractor or you can do it yourself.
Either way, make sure to place support structures before the digging begins. Then, you can finish the excavation and lay down new foundations.
While a crawl space dugout is no easy task, completing the project is fulfilling and boosts the value of your home.
I have a bachelor’s degree in Computer Information Systems and over 10 years of experience working in IT. As a homeowner, I love working on projects around the house, and as a father, I love investigating various ways to keep my family safe (whether or not this involves tech). I’ve also played guitar for almost 20 years and love writing music, although it’s hard to find the time these days.