How should I anchor my pergola post?
What’s the difference between anchoring pergola posts above ground, and sinking them 3 feet under?
You can do it both ways, but sinking the posts is a better alternative if you’re going to buy the pergola in the Mature or Old-Growth Redwood. Both wood grades are very decay resistant in moist conditions (like underground) and will hold up fine for decades. The Redwood wood grade will only last 15 years if buried 3 feet underground. This is the reason both anchoring options are mentioned.
Sinking the posts is a structurally stronger way to attach the set. You’ll pay a bit more for the longer posts, but you don’t have to buy the anchoring kit. Some customers like the trim pieces around the base of the posts even when they are sinking the posts in the ground. If you are planning on sinking the posts and want the trim pieces, just let us know in the “Special Instructions & Custom Requests” box upon checkout. We’ll send them at no extra charge.
If you are in a relatively dry climate (less than 20 inches of rain per year), the Redwood wood grade is the best investment because it will last a couple decades in the drier climate and is less expensive than Mature or Old-Growth Redwood. If you’re going with the Redwood wood grade, do the concrete work and attach above ground for a long-lasting structure. If you’re planning to purchase the Mature Redwood, sink the posts and order them 12 feet long.
We rarely sell pergola kits in Old-Growth. It’s an exquisite wood most of our customers order for furniture instead. We will gladly build your pergola in Old-Growth if you prefer, but for most parts of the country, your best investment option in relation to durability is the Mature Redwood. It will last 25 to 30 years without maintenance even in severe climates, while the Old-Growth may last 5 to 10 years longer but at a significant price premium.
