How to Anchor an Outdoor Pergola to a Concrete Slab

A pergola.
  • 2-5 hours
  • Advanced
  • 0-150
What You'll Need
Metal Anchors
Lag Bolts
Anchor Bolts
Hammer Drill
Masonry Bit
Ratchet Wrench
Cordless Drill
Drill Bits

An outdoor pergola is a great way to shield your patio from the harsh rays of the sun while you sit out and enjoy the summer weather. The pergola can either be attached to the house or constructed as a free-standing entity. In either case, you will need to anchor the posts onto concrete. Trying to set the posts onto the concrete without any type of anchor will result in it being knocked over in the event of strong winds. Here are the steps to take to anchor your pergola quickly and easily.

Step 1 - Locate Anchor Position

First, you will need to decide where the anchors are going to go. The posts will be positioned in the corners of the pergola. Mark the area with an "X". Place a metal anchor onto the area and trace its outline with a marker. While the anchor is positioned on the cement you can also mark the bolt holes on the bottom.

Step 2 - Drill Anchor Bolt Holes

To drill into the concrete pad you will need a hammer drill outfitted with a masonry bit. Make sure the bit is the same diameter as the holes on the metal anchor. Stand the drill straight up and down on the mark for the hole and start drilling. You only need to go down as far as the anchor bolt. You can mark the drill bit with a piece of tape to show where you should stop.

Step 3 - Secure Metal Anchor

A pergola.

After the holes have been drilled into the concrete slab, you should brush away any concrete dust. Place the anchor into position and place the anchor bolts into the holes. Use your ratchet to tighten the anchor bolt into the concrete. As the bolt is turned the anchors will press against the concrete for a very strong hold.

Step 4 - Place Post in Anchor

Once the anchor is secured to the concrete, you need to stand the post into position. Once the post is in position, mark the holes where the lag bolts will be secured. Use a marker and make dark lines that are easy to see. Remove the post and position it on a work table for drilling.

Step 5 - Drill Lag Bolt Holes

The lag bolts will be driven into the wood so that the threads will hold it tight. Because of this you will need to only drill small pilot holes. They do not have to be deep or very large in diameter. Use a regular drill with a small drill bit.

Step 6 - Secure Posts to Metal Anchor

An outdoor pergola.

Stand the posts back into the metal anchors and make sure it will stand upright. If you have a friend nearby, this is a good time to recruit them. Place the lag bolt into the space and begin driving it into the post. Use a ratchet wrench for this job. Repeat the process until all the bolts are in place.

Step 7 - Repeat for Each Post

After you have the first post of your outdoor pergola secure, and then repeat the process for each one.