How to Set Fence Posts That Won’t Rot
Updated: Jun. 14, 2022Keep moisture and insects from destroying your cedar fence posts.
Time A full day
ComplexityIntermediate
Cost$51–100
Introduction
Cedar has a reputation for durability, but unless a few guidelines are followed, cedar posts can fail in as few as five years. Three factors contribute to this early failure: poor drainage, low-quality wood and poor protection against insect damage. Here's how to install new cedar fence posts and avoid the problems that made your old posts rot.Tools Required
- Bucket
- Caulk gun
- Paintbrush
- Posthole digger
- Shovel
- Trowel
- Wheelbarrow
Materials Required
- Acrylic caulk
- Aggregate
- Cement
- Wood preservative
Project step-by-step (5)
Step 1
Pick the Right Posts
- Don’t use posts that contain sapwood. Instead, use heartwood, because it’s denser and more insect-resistant.
Step 2
Treat the Post With Preservatives
- Soak the bottom of the posts in a wood preservative containing copper napthanate, such as Cuprinol.
- Note: Available at some paint stores and home centers, this wood treatment is specifically designed for in-ground applications.
Step 3
Insert Aggregate
- Place about 6 inches of aggregate in the bottom of the posthole to allow for drainage.
- Pro Tip: The bottom of the post should extend a few inches into the aggregate as shown.
Step 5
Caulk Around the Fence Post Base
- Apply high-quality exterior acrylic latex caulk, or silicone specifically designed to adhere to concrete, at the base of the post.
- Note: This will seal the gap between the concrete and post that’s caused by freeze/thaw cycles.
Originally Published: September 14, 2020
