Decks and porches

Preventing Porch Wood Rot Before It Starts

Where porch rot starts, how to check for it and the simple habits that keep porch wood sound in humid Georgia weather.

Porches take a beating in Georgia. Long, humid summers, heavy storms and shade from big trees keep wood damp, and damp wood is what rot needs. The good news is that most porch wood rot can be prevented, or caught early, with some simple habits.

How rot gets started

Wood rot is caused by fungi that feed on wood. They need moisture to grow. Wood that stays wet, or gets wet and dries over and over without ever fully drying, is at risk. Rot often starts where water collects or soaks in:

• End grain. Cut ends of boards drink up water like a straw.
• Joints. Where porch posts meet the floor, where rails meet posts, where trim meets siding.
• Flat surfaces that hold water, like rail caps and the tops of post bases.
• Boards near the ground or buried in soil or mulch.
• Under drips from a clogged or missing gutter.
• Shady corners that never dry out.

Older homes with original wood porches are especially worth watching, since that wood has seen a lot of weather.

Check your porch twice a year

A spring and fall walk-around catches most problems early. Bring a screwdriver and look for:

• Peeling, bubbling or cracked paint
• Dark stains or gray, spongy-looking spots
• Soft spots in floorboards when you step on them
• Posts that feel soft at the bottom
• Gaps in caulk where trim meets siding
• Rails that wobble
• Mushrooms or fuzzy growth on wood

Press the screwdriver into suspect spots. Sound wood resists. Rotten wood gives way easily. Our guide on signs a deck needs repair covers more things to check.

Prevention tips that work

Keep a good paint or stain film

Paint and stain are your wood's raincoat. Once paint starts peeling, water gets behind it and stays there. Scrape loose paint, prime bare wood and repaint as needed. Pay extra attention to the bottom edges of posts and trim.

If your home was built before 1978, the old paint may contain lead. Don't dry-sand or burn it off. Our older home repairs guide explains why.

Seal end grain and joints

When boards are cut during repairs, prime or seal the cut ends before installing them. Keep joints caulked with an exterior-grade caulk, but don't caulk spots where water needs to drain out.

Manage roof water

Clean gutters regularly, especially after pine pollen season and leaf fall. Make sure water from downspouts doesn't splash onto porch steps or soak the ground around porch posts.

Let it breathe

Air movement helps wood dry. Keep the space under the porch open to airflow where you can. Trim shrubs back from railings and posts. Don't pile firewood, boxes or rugs against wood.

Keep wood off the ground

Pull soil and mulch away from post bottoms, skirting and siding. Posts sitting directly on dirt or concrete without a gap tend to wick up moisture. Post bases that hold the wood slightly above the surface help.

Use the right materials for repairs

Use lumber rated for ground contact where wood will be close to the ground or hard to dry out. Use exterior-rated fasteners that resist rust. Some folks also use borate wood treatments on bare wood during repairs as an added layer of protection.

Sweep and wash

Leaves, pine needles and dirt hold moisture on porch floors. Sweep often, and wash off mildew gently. Avoid blasting old wood with high pressure, which can tear up soft grain.

When to repair vs. replace

• Small, shallow spots in trim or a board can sometimes be dug out and filled with exterior epoxy filler, then primed and painted.
• A soft board should be replaced, along with checking what's under it.
• Posts, beams and joists that carry weight should be replaced if they're rotten, not patched. Structural work may need temporary support while the piece is swapped.

If rot has spread into the house framing, or the porch roof is sagging, you may need a general contractor.

Get your porch looked at

We handle porch repair, deck repair and exterior painting. Text a photo of the problem spot to (706) 594-5049, or use our free estimate form, and we'll give you a free estimate.