Should I repair my old pergola or tear it down and rebuild?

Start with an honest assessment

Most old pergolas in Carlsbad fall into one of three groups. Some are sound structures with a failed finish and a couple of bad pieces. Some have rot at the post bases but good wood above. And some were built too light in the first place and have been slowly failing since.

Figuring out which one you have takes an awl and a ladder. Probe the base of every post, the top of every post, the top of every beam and the joint where each rafter lands. Note what is soft, what is cracked through, and what is just weathered. Weathered is cosmetic. Soft is structural.

When repair makes sense

Rot confined to the bottom of a post can be cut out and a new section spliced in on a standoff base, with the splice hidden by a base wrap. Individual rafters with bad checks or rotted tails can be replaced one at a time and stained to match. Loose through-bolts can be tightened and rusted hardware swapped for galvanized or stainless.

A gray, checked surface on sound wood is a restoration job rather than a rebuild. Cleaning, brightening, light sanding and a pigmented stain bring back more than most homeowners expect, and that is work we do regularly on pergolas, decks and front doors.

If the proportions are good and the footprint works, repair preserves something that already belongs to the house.

When rebuilding is the better answer

Rot that has climbed a post, or that has reached a beam, means the load path is compromised, and chasing it piece by piece costs more than replacing the frame. Beams split through their depth cannot be mended. Joints that have opened at every post mean the connections were never adequate.

Undersized structure is the other reason. A pergola built from four-by-four posts and two-by-six beams on a long span will sag and rack no matter how many pieces you replace. If it never looked right, repairing it will not make it look right.

Rebuilding is also the moment to fix what the original got wrong: raise a low beam, run rafters the other way for afternoon shade, add purlins, move a post that is in the way, or set a base on a proper footing instead of a thin slab.

Same footprint, better pergola

The entry pergola rebuild illustrates the middle path. The original structure had the right footprint and height and framed an arched entry well. But the beams had split, the joints had failed and a corner post had rotted through at the top. It was past saving as a structure.

We rebuilt it in the same footprint so it still met the roofline and the arch the way the old one had, then corrected what was wrong: heavier beams, lapped and through-bolted joints that drain, tighter rafter spacing and a warm penetrating finish. The homeowners got the pergola they thought they had, built to last this time.

Questions to ask before deciding

Where is the rot, and how far has it traveled? Are the posts on standoff bases, in concrete, or flat on a slab? Are the members sized for the spans, or does it flex when pushed? Do you like the size, height and location? Will a repair leave you with a structure you still want to maintain?

If the answers point to local problems on a frame you like, repair it and recoat it. If they point to a structure that was never right, rebuild it once, properly, and then maintain it. Either way, the post bases and the finish are where the next twenty years get decided.

• Repair: local rot, bad rafters, loose hardware, tired finish
• Rebuild: rot in the load path, split beams, failed joints everywhere, undersized members
• Rebuilding is the chance to fix proportion, shade and footings
• Keep the footprint when it already works

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