Planning Your Outdoor Fireplace

Before starting your project, focus on location, size, design, materials, and local codes to ensure a successful outdoor fireplace build.

Choosing the Right Location

Select a location that is at least 10 feet away from your house and any structures or trees. The ground should be level to provide a stable foundation. Factor in the direction of prevailing winds and ensure a safe distance from flammable surfaces.

Determining the Size and Design

Design your fireplace to complement the aesthetics of your outdoor space. Use the following measurements as a guide:

Fireplace Component	Suggested Size
Width	3 to 4 feet
Depth	2 to 3 feet
Height	4 to 6 feet (Chimney)
	3 feet (Firebox height)

Consider built-in seating or storage for firewood in your design.

Selecting Materials

Choose materials that are fire-resistant and suitable for outdoor conditions. Common selections include:

• Bricks or fire bricks for the inner structure
• Stone or veneer for the external finish
• Cast iron or steel for the firebox and grate

Materials should withstand high temperatures and resist outdoor elements.

Understanding Local Building Codes

Research local regulations to ensure compliance. Specifics may include:

• Minimum distance from other structures
• Chimney height requirements
• Emission standards and fire safety rules

Obtain any necessary permits before proceeding with construction.

Foundation and Safety

Building a durable outdoor fireplace requires a strong foundation and attention to safety to ensure longevity and prevent accidents.

Preparing the Foundation

Site Selection: Choose a level surface clear of overhead obstructions. Remove any organic material and dig a trench about 12 inches deep for the footing.

Concrete Mix: Pour a 6-inch layer of gravel for drainage, then add a wooden frame to hold the concrete. Mix the concrete according to the manufacturer's specifications and pour it into the frame, leveling it with a trowel.

Ensuring Proper Ventilation

Chimney Construction: Your fireplace must have a well-designed chimney to expel smoke effectively. The chimney should extend at least 2 feet above any nearby structures and include a spark arrestor.

Airflow: Ensure an opening at the base of the firebox for airflow. Proper airflow is crucial for efficient burning and reducing smoke.

Incorporating Fire Bricks for Heat Resistance

Material Selection: Use fire bricks, which are specifically designed to withstand high temperatures, for the inner layer of the firebox.

Mortar Type: Use refractory mortar between fire bricks as it's resistant to high heat. Avoid using standard mortar, which can crack under high temperatures.

Building the Fireplace Structure

When constructing an outdoor fireplace, precision in each step is crucial for a safe and durable structure. Begin with a sound base and progress systematically.

Laying the First Row of Bricks or Stones

Properly laying the first row is fundamental to the stability of your fireplace. Use a mix of one part cement, one part lime, and five parts sand for your mortar. Check each brick or stone for level and alignment, utilizing a 4-foot level as a guide.

1. Outline the perimeter of the fireplace on the foundation.
2. Trowel a consistent mortar layer about 1 inch thick within your outline.
3. Place each brick or stone firmly into the mortar, pressing down slightly.

Creating the Firebox

The firebox is the core where the fire will burn. Use firebricks for this high-heat area, which can withstand temperatures above 1,800 degrees Fahrenheit.

• Begin by laying firebricks on a thin layer of refractory mortar.
• Leave a gap of 1/8 inch between firebricks for expansion.
• Construct the back wall vertically and angle the side walls slightly towards the opening for better heat reflection.

Constructing the Throat and Chimney

The throat funnels smoke into the chimney, while the chimney directs it away from your space.

• Build the throat just above the firebox using angled bricks to narrow the passage smoothly.
• For the chimney, stack bricks or stones to at least 3 feet above the roofline, maintaining a consistent flue size.
• Use a chimney cap to prevent rain from entering.

Adding the Hearth and Mantle

The hearth is the visible floor area in front of the firebox, and the mantle is the horizontal shelf above the fireplace opening.

• Install the hearth using flat, stable stones or bricks, leaving a minimum of 16 inches of depth from the firebox opening.
• Place the mantle at least 12 inches above the firebox opening to ensure suitable clearance.

Note: Always adhere to local building codes and regulations, and consider consulting a professional for the construction to ensure safety and compliance.

Finishing Touches

With the main structure of your outdoor fireplace established, it's time to apply the final touches that ensure durability and aesthetic appeal.

Applying Mortar and Sealant

After the stonework is complete, check for and fill any gaps with mortar to solidify the structure. Use a trowel to evenly spread the mortar, and ensure it matches the color of your existing mortar. Once the mortar sets, apply a waterproof sealant to prevent moisture damage. This protectant should be applied to all exposed areas, following the manufacturer's instructions. Here is a brief list of steps:

1. Inspect for gaps and use mortar to fill them.
2. Smooth out with a trowel for even distribution.
3. Once mortar sets, apply waterproof sealant for protection.

Installing Doors or Screens

Doors or screens are essential for safety and controlling the fire. When choosing a door or screen, make sure it fits the fireplace opening perfectly. For screens, select a material that withstands high heat, such as wrought iron or steel. Installation varies, but typically involves securing the unit with brackets or hinges directly onto the fireplace. The following table outlines the steps:

Step	Description
Measure Fireplace Opening	Ensure the doors/screens fit your dimensions.
Choose Appropriate Material	Opt for high-heat materials like iron or steel.
Install with Proper Fixtures	Use brackets or hinges to secure the unit.

Curing the Fireplace

Before the fireplace is used for the first time, it must undergo a curing process to remove moisture from the masonry. This involves lighting small, low-heat fires that gradually increase in size over the course of several days. Be patient during this process and follow these steps:

• Start with a small fire using kindling and a few pieces of wood.
• Allow the fire to burn out naturally, and let the fireplace cool.
• Repeat this process daily, gradually increasing the fire size.

Maintenance and Upkeep

Maintaining your outdoor fireplace is crucial for safety and longevity. Follow these specific guidelines to keep your fireplace in top condition.

Regular Cleaning Procedures

• Ash Removal: After each use, once the ash has cooled, scoop it out with a metal ash bucket. This prevents accumulation that can impede air flow and cause smoke problems.

• Soot and Creosote: At least once a month, inspect for soot and creosote buildup. Use a chimney brush to clean the flue. This reduces the risk of chimney fires.

Seasonal Inspections

• Structural Integrity: Examine the fireplace's masonry for any cracks or damage at the start and end of the season. Minor repairs can be done using fire-resistant mortar.

• Chimney Cap: Ensure that the chimney cap is intact to prevent debris and animals from entering the chimney.

Weatherproofing Tips

• Sealant Application: Apply a waterproof sealant to the exterior bricks or stones to protect against moisture damage.

• Furniture Covers: If you have outdoor seating near your fireplace, cover it with weatherproof covers when not in use to shield it from the elements.