Pergola With Firepit

We built a pergola with lights and a firepit on a round concrete pad. The yard is sloped so we also built a retaining wall on the uphill side. We then added a flagstone path, steps and patio with an inlaid turtle.

Pergola Tools & Supplies Needed-   

Tools

·     Measuring tape

·     4 ft. level

·     String plumb line

·     Chalk for marking

·     Reciprocating saw

·     Electric drill

·     Sawhorses

·     12″ long 1/2″ bit

·     skill saw/circular saw

·     drill driver

·     auger and/or post hole digger

·     wheelbarrow for mixing cement

·     Paint brushes and paint pan

Materials (based on an 18-foot diameter circular/octagonal pergola)

Materials Needed-

• 18 posts 4” x 4” and 10 feet long
• 8 bags of cement
• Deck screws 4” long
• 24 lag bolts, 3" long
• 8 top plate planks 2” x 8” and 10 feet long
• Waterproofing stain
• Optional black medal T-bars for decoration

Determine the center of the pergola (the center of the firepit). Using a plumb line tied to a post placed in the center, measure out and mark with chalk, 9 feet in your first direction. Then again make another mark where each of your 8 posts will be installed every 8 feet in a circle from the first marking.

Using an auger/posthole digger, dig a hole at each marking at least 2 feet deep. Place a 4” x 4” post in each hole with a flat face of each post facing the center of the pergola.

Using a bag of cement for each hole, mix the cement in the wheelbarrow according to product instructions. Pour cement into one hole at a time and use your level on all angles of the post to ensure a straight post. We used scrap wood pieces to stake into the ground next to the cement you just poured and nail to the bottom of each post while the cement dried and removed them after the cement was set. 

Cut your posts to the desired height or to the height of the shortest post (8 – 9 feet). To do this, use a rotary laser level to ensure that all the posts are level and at the same height. 

Mark a triangle on top of each post with the flat side facing the center of the firepit and the point towards the center of the flat side on the outer ring of the circle.

Using a reciprocating saw, cut vertically 3 ½” on each of the 2 lines, down the triangle you drew. Then, cut a small, angled slice horizontally according to the illustration below, into the side of the post, leaving a 3 ½-inch high triangle section on top of the post.

Customize exact measurements. Place your 4” x 4” crossbeams on top of the cut posts making sure to align the interior edge of the beam with the corner of each post. From the underside of the post, use a pencil to mark the angle to the bottom side of the beam. Cut only one piece at a time, this will ensure that the beams and post will fit tightly together. Each top beam should be measured separately, we found that they were each at slightly different angles. Secure each one using 4” deck screws angled from the outer edge screwing into the pie-shaped section on top of the post section.

The last, building step is to cut and install the top plate. These plates are mitered so that they meet evenly in the corners over each post. Measure, cut and place your plates according to the illustration below, overlapping the joint.

Using 4″ deck screws, secure the top plate to the crossbeams. Also, place screws about every 10” through the top plate into the beam.

This step was definitely the most difficult for us. Each 2-foot support piece had to have a 45 degree angle at the top and a custom angle at the bottom. We found each one to be slightly different. We cut the top end with a 45 degree angle, then held that piece up and marked the bottom angle with a pencil.

Finally, we used 3" long lag bolts to attached the T-plates that my husband bent manually to fit at the top of each post joint.

Finishing the Pergola

The final step is to stain and seal your project with a water-proofing stain. We recommend several coats with ample drying time in between each coat. We opted to place black medal T-plates at the top of each post to cover the joint.

Hang string lights around the outer rim, ENJOY!