Wood porch columns rot from the bottom up. Water sits at the base, soaks into the end grain and, over a few seasons, turns a handsome column into a soft, peeling eyesore. The good news: you don't have to replace a rotted column with another wood column that will fail the same way. This guide explains how to deal with the structural post first, then finish it with a composite column wrap that will not rot.
The short version: Column wraps and column shafts are decorative covers, not structural supports. A sound structural post always carries the load inside the wrap. Fix or replace the post first, then wrap it. Browse exterior column wraps.
Step 1: Check Whether the Rot Is Cosmetic or Structural
Before choosing a wrap, find out what the rot has damaged.
- Cosmetic rot: the decorative wood casing is soft or peeling, but the structural post inside is solid. You can remove the old casing and wrap the existing post.
- Structural rot: the post that holds up the porch roof is soft, cracked or crushed at the base. The post must be repaired or replaced before any wrap goes on.
Replacing a structural post means temporarily supporting the porch roof while the old post comes out. That is a job for a qualified contractor, and it may need a permit. Size the new post to local building codes for your span, roof load and snow load.
Step 2: Wrap the Structural Post with a Composite Column Wrap
Once the post is sound, a composite column wrap gives it a finished architectural look. Mouldex column wraps have a lightweight, moisture-inert foam core with a hard cementitious coating, so they will not rot, split or attract insects the way wood casings do. They are decorative only: they add no load-bearing capacity, and the structural post inside must carry all loads.
Choosing a Style
- Square column wraps such as the Piazza and Edgeley suit Craftsman, farmhouse and modern homes.
- Round column wraps such as the Classica and fluted Roma suit classical, Colonial and Georgian architecture.
- Capitals and bases finish the top and bottom of the column: see square capitals and bases and round capitals and bases.
Installation Overview
- Remove the old decorative casing and confirm the structural post is sound and plumb.
- Measure the post and choose a wrap with enough interior clearance to fit around it.
- Fit the wrap around the post and secure it with exterior adhesive, following the installation guidelines.
- Add the capital and base, then seal the joints.
- Prime and paint. All Mouldex mouldings are primed and painted after installation.
Why Composite Wraps Outlast Wood
| Wood column casing | Mouldex composite column wrap | |
|---|---|---|
| Rot and insects | Vulnerable, especially at the base | Moisture-inert core; will not rot or attract insects |
| Splitting and warping | Common as seasons change | Will not split or warp |
| Weight | Heavy in solid timber | Lightweight, easy to handle |
| Maintenance | Regular scraping, sealing and repainting | Paint once; no rot repairs |
Frequently Asked Questions
Are column wraps structural?
No. Column wraps and column shafts are decorative, non-load-bearing covers. A structural post inside the wrap must carry all vertical and lateral loads, sized to local building codes.
Can I wrap a rotted post?
Only if the rot is in the decorative casing and the structural post is sound. If the structural post is rotted, have it repaired or replaced by a qualified contractor before installing a wrap.
Do composite column wraps need painting?
Yes. They are primed and painted after installation, then need no rot repairs or re-sealing.
Ready to replace your porch columns? Browse exterior column wraps, order a free sample kit or send us your column measurements.
