How to Build Your Own Underground Root Cellar: A Comprehensive Guide

Root cellars are an age-old method of food preservation, allowing you to store fruits, vegetables, and even some meats for extended periods without relying on electricity. In a world increasingly concerned with sustainability and self-sufficiency, building an underground root cellar offers a practical and rewarding way to connect with traditional practices and reduce your reliance on modern conveniences. This comprehensive guide provides detailed steps and instructions for building your own underground root cellar, empowering you to create a valuable asset for your home and garden.

Why Build an Underground Root Cellar?

Before diving into the construction process, let’s consider the many benefits of having a root cellar:

* **Food Preservation:** The primary function of a root cellar is to provide a cool, dark, and humid environment that slows down the ripening process of fruits and vegetables, preventing spoilage and extending their shelf life. This allows you to enjoy the harvest from your garden or local farm throughout the winter months.
* **Cost Savings:** By storing your own produce, you can significantly reduce your grocery bills, especially during the off-season when fresh produce is often more expensive.
* **Sustainability:** Root cellars offer a sustainable alternative to refrigeration and freezing, reducing your energy consumption and environmental impact.
* **Self-Sufficiency:** Having a root cellar empowers you to become more self-sufficient, reducing your reliance on external food sources and building resilience in the face of unforeseen circumstances.
* **Flavor Enhancement:** Certain foods, such as potatoes and apples, actually improve in flavor after being stored in a root cellar for a period of time.
* **Emergency Preparedness:** In the event of a power outage or other emergency, a root cellar can provide a valuable source of food and water.

Planning Your Root Cellar

The first step in building a root cellar is careful planning. Consider the following factors:

1. Location

The ideal location for a root cellar is a naturally cool and shaded area, preferably on the north side of your house or a nearby hill. Avoid areas that are prone to flooding or have poor drainage. The soil should be well-draining and stable enough to support the structure. Proximity to your garden and house are also desirable.

* **Soil Type:** Well-draining soil like sandy loam is ideal. Clay soil can retain too much moisture, potentially leading to rot. Conduct a percolation test to assess your soil’s drainage.
* **Water Table:** The water table should be at least a few feet below the floor of your root cellar. Dig a test hole to check the water table level, especially during the wet season.
* **Sun Exposure:** Minimize direct sunlight exposure to keep the root cellar cool. The north side of a building or a shaded area under trees is preferred.
* **Accessibility:** Consider how easily you can access the root cellar, especially during winter when snow and ice may be present. A location close to your house will make it more convenient to use.

2. Size and Design

The size of your root cellar will depend on the amount of food you plan to store. A small root cellar (6×8 feet) may be sufficient for a small family, while a larger family may need a larger space (10×12 feet or more). The design should prioritize insulation, ventilation, and humidity control. Common designs include:

* **Underground Room:** This is the most traditional type of root cellar, built entirely underground. It offers the best insulation and temperature stability.
* **Hillside Cellar:** Built into a hillside, this type of root cellar takes advantage of the earth’s natural insulation. It’s often easier to construct than a fully underground cellar.
* **Basement Cellar:** If you have a basement, you can convert a section of it into a root cellar by insulating the walls and ceiling and providing proper ventilation.
* **Above-Ground Cellar (Earth-Sheltered):** While not strictly underground, these cellars are built above ground and then covered with earth to provide insulation. They offer a compromise between ease of construction and temperature stability.

Consider accessibility when designing your root cellar. A ramp is often easier to navigate than stairs, especially when carrying heavy loads of produce.

3. Materials

The materials you choose will depend on your budget, skills, and the availability of resources. Common materials include:

* **Concrete Blocks:** Durable and relatively inexpensive, concrete blocks are a popular choice for building root cellar walls.
* **Poured Concrete:** Poured concrete provides a strong and waterproof structure, but it requires more skill and equipment to install.
* **Wood:** Wood can be used for framing and shelving, but it’s important to choose rot-resistant varieties like cedar or redwood.
* **Stone:** Stone is a natural and attractive material, but it can be difficult to work with.
* **Insulation:** Insulation is crucial for maintaining a stable temperature in your root cellar. Consider using rigid foam insulation, fiberglass batts, or even natural materials like straw bales.
* **Gravel:** Gravel is used for drainage and to prevent moisture from seeping into the root cellar.
* **Plastic Sheeting:** Plastic sheeting is used as a vapor barrier to prevent moisture from condensing on the walls and ceiling.

4. Ventilation

Proper ventilation is essential for maintaining the correct humidity levels in your root cellar and preventing the buildup of mold and mildew. You’ll need at least two vents: one near the floor to draw in cool air and one near the ceiling to exhaust warm, moist air. The size of the vents will depend on the size of your root cellar.

* **Intake Vent:** Located near the floor to draw in cool air. Should be screened to prevent pests from entering.
* **Exhaust Vent:** Located near the ceiling to exhaust warm, moist air. May need a damper to control airflow during different seasons.
* **Vent Size:** A general rule of thumb is to have 1 square inch of vent area for every 10 cubic feet of root cellar volume. Adjust as needed based on your specific conditions.

5. Temperature and Humidity Control

The ideal temperature for a root cellar is between 32°F and 40°F (0°C and 4°C), and the ideal humidity level is between 80% and 95%. You can control the temperature and humidity by adjusting the ventilation, adding moisture (e.g., by spraying the floor with water), or adding insulation.

* **Monitoring:** Use a thermometer and hygrometer to monitor the temperature and humidity levels in your root cellar.
* **Adjustments:** Adjust ventilation as needed to maintain the desired temperature and humidity. In dry climates, you may need to add moisture regularly.
* **Insulation:** Proper insulation is key to maintaining a stable temperature and reducing temperature fluctuations.

Step-by-Step Construction Guide

Once you’ve planned your root cellar, you can begin the construction process. The following steps provide a general guideline, but you may need to adapt them based on your specific design and location.

Step 1: Excavation

Dig the hole for your root cellar, making sure to account for the dimensions of the walls, floor, and roof. The hole should be slightly larger than the planned dimensions of the cellar to allow for working space and backfilling.

* **Safety:** Call your local utility companies before you dig to locate any underground utilities.
* **Soil Removal:** Use a shovel, pickaxe, or backhoe to remove the soil. Store the soil nearby for backfilling later.
* **Leveling:** Ensure the bottom of the excavation is level and compacted.
* **Wall Support (if needed):** For unstable soil, consider using temporary shoring to prevent cave-ins.

Step 2: Foundation

Pour a concrete foundation to provide a stable base for the walls. The foundation should be thick enough to support the weight of the structure and prevent settling.

* **Forms:** Build wooden forms to contain the concrete.
* **Reinforcement:** Add rebar to the concrete for added strength.
* **Pouring:** Pour the concrete into the forms and level it with a screed.
* **Curing:** Allow the concrete to cure for at least 7 days before building on it.

Step 3: Walls

Build the walls of your root cellar using concrete blocks, poured concrete, stone, or other suitable materials. Ensure the walls are strong and waterproof.

* **Concrete Blocks:** Lay the blocks in a staggered pattern, using mortar to bind them together. Reinforce the walls with rebar.
* **Poured Concrete:** Build forms for the walls and pour concrete into them. Vibrate the concrete to remove air bubbles.
* **Stone:** Carefully stack the stones, using mortar to bind them together. Ensure the walls are stable and waterproof.
* **Waterproofing:** Apply a waterproof coating to the exterior of the walls to prevent moisture from seeping into the root cellar. Options include asphalt emulsion, rubber coating, or specialized waterproofing membranes.

Step 4: Roof

Construct a strong and waterproof roof over your root cellar. The roof should be able to support the weight of the soil and any snow or other loads.

* **Framing:** Build a wooden frame for the roof, using pressure-treated lumber. Slope the roof slightly to allow for water runoff.
* **Sheathing:** Cover the frame with plywood or OSB sheathing.
* **Waterproofing:** Apply a waterproof membrane to the sheathing to prevent leaks.
* **Reinforcement:** Add extra support to the roof if you plan to cover it with a thick layer of soil.
* **Alternative Roofs:** Consider using a concrete slab roof for added strength and durability, especially if you plan for heavy earth covering.

Step 5: Insulation

Insulate the walls and roof of your root cellar to maintain a stable temperature. Use rigid foam insulation, fiberglass batts, or other suitable materials.

* **Rigid Foam:** Cut the insulation to fit snugly between the framing members. Seal the seams with tape.
* **Fiberglass Batts:** Install the batts between the framing members, ensuring they are not compressed.
* **Natural Insulation:** Consider using straw bales or other natural materials for insulation. Pack them tightly around the walls and roof.

Step 6: Vapor Barrier

Install a vapor barrier on the inside of the insulation to prevent moisture from condensing on the walls and ceiling. Use plastic sheeting or other suitable materials.

* **Installation:** Overlap the seams of the vapor barrier and seal them with tape.
* **Purpose:** Prevents moisture from the inside of the root cellar from reaching the insulation, which can reduce its effectiveness and lead to mold growth.

Step 7: Backfilling

Backfill around the walls and roof of your root cellar with the soil you excavated earlier. Compact the soil in layers to prevent settling.

* **Compaction:** Use a hand tamper or plate compactor to compact the soil. This is crucial to prevent settling and potential damage to the structure over time.
* **Drainage:** Slope the soil away from the walls to direct water away from the root cellar.
* **Topsoil:** Add a layer of topsoil to the surface and plant grass or other vegetation to help stabilize the soil and prevent erosion.

Step 8: Ventilation

Install the ventilation pipes, ensuring they are properly screened to prevent pests from entering.

* **Placement:** Position the intake vent near the floor and the exhaust vent near the ceiling.
* **Screening:** Cover the vents with wire mesh to prevent insects and rodents from entering.
* **Adjustability:** Consider adding dampers to the vents to control airflow during different seasons.

Step 9: Shelving and Storage

Build shelves and storage bins inside your root cellar to organize your produce. Use rot-resistant materials like cedar or redwood.

* **Spacing:** Leave enough space between shelves for air circulation.
* **Materials:** Use untreated wood to avoid contaminating your food.
* **Organization:** Group similar items together for easy access.
* **Rotation:** Implement a system for rotating your stock, using older items first.

Step 10: Door and Entrance

Install a sturdy and insulated door to keep the root cellar cool and secure. A ramp is often easier to navigate than stairs.

* **Insulation:** Insulate the door to prevent heat loss.
* **Weatherstripping:** Add weatherstripping to seal the door and prevent drafts.
* **Security:** Install a lock to secure the door and prevent unauthorized access.
* **Ramp vs. Stairs:** A ramp provides easier access, especially when carrying heavy loads. Ensure the ramp has a non-slip surface.

Maintaining Your Root Cellar

Once your root cellar is complete, it’s important to maintain it properly to ensure its longevity and effectiveness.

* **Regular Cleaning:** Clean the root cellar regularly to remove any spoiled produce or debris.
* **Pest Control:** Monitor for pests and take steps to control them. Use traps or natural repellents.
* **Humidity Control:** Adjust the ventilation or add moisture as needed to maintain the desired humidity level.
* **Temperature Monitoring:** Regularly monitor the temperature and make adjustments as needed.
* **Proper Storage Techniques:** Learn the best storage techniques for different types of produce to maximize their shelf life.

Tips for Storing Specific Foods

Different foods require different storage conditions. Here are some tips for storing common items in your root cellar:

* **Apples:** Store apples in a cool, humid environment. Wrap each apple individually in newspaper to prevent spoilage from spreading.
* **Potatoes:** Store potatoes in a cool, dark, and dry environment. Avoid storing them near apples or other fruits that produce ethylene gas, which can cause them to sprout.
* **Carrots:** Store carrots in a cool, humid environment. Pack them in damp sand or sawdust to prevent them from drying out.
* **Onions:** Store onions in a cool, dry, and well-ventilated environment. Hang them in mesh bags to allow for air circulation.
* **Garlic:** Store garlic in a cool, dry, and well-ventilated environment. Hang it in braids or mesh bags.
* **Cabbage:** Store cabbage in a cool, humid environment. Wrap it in newspaper or plastic wrap to prevent it from drying out.
* **Root Vegetables (Beets, Turnips, Parsnips):** Store in damp sand or sawdust in a cool, humid environment. Trim the greens to prevent moisture loss.

Troubleshooting Common Problems

Even with careful planning and construction, you may encounter some problems with your root cellar. Here are some common issues and how to address them:

* **Excessive Moisture:** Increase ventilation and ensure the drainage is working properly. Consider adding a dehumidifier.
* **Insufficient Humidity:** Add moisture by spraying the floor with water or placing containers of water in the root cellar.
* **Temperature Fluctuations:** Improve insulation and adjust ventilation as needed.
* **Pest Infestations:** Identify the pests and take appropriate control measures. Seal any cracks or openings in the walls and foundation.
* **Mold and Mildew:** Increase ventilation and clean the affected areas with a bleach solution.

Conclusion

Building an underground root cellar is a rewarding project that can provide you with a sustainable and cost-effective way to preserve food. By following these detailed steps and instructions, you can create a valuable asset for your home and garden that will allow you to enjoy the fruits (and vegetables) of your labor throughout the year. Remember to plan carefully, use quality materials, and maintain your root cellar properly to ensure its longevity and effectiveness. Embrace the tradition and reap the benefits of having your very own underground food storage solution.