After the rot repair: how to keep water out so the wood stays sound for years

Three habits that protect a repair

Rot comes back when water keeps reaching the wood, so prevention comes down to three habits: keep water off and away from the house, keep paint, stain and caulk intact so water cannot soak in, and check your exterior wood once or twice a year so small problems are caught early. A properly done epoxy repair is sealed and built to shed water, but the original wood around it still depends on you.

I'm Ben Henderson, owner of Preservan Dallas. We at Preservan repair rotted windows, doors, trim, posts and decks in place with structural epoxy, and we stain and wash fences and decks. At every final walkthrough, the conversation turns to the same question: what do I do now so I never need you again? This guide is that conversation, written down.

The wood beside the repair is what needs watching

Once a section has been rebuilt with structural epoxy and sealed with primer and paint, that section is no longer the weak point. Preservan describes well-maintained epoxy repairs as outlasting the surrounding lumber. The original wood next to it is a different matter. If the conditions that rotted the first section are still there, the next few inches of sill or the other leg of the jamb are next in line.

That is why the inspection before any repair should identify the moisture source, and why the work after the repair is mostly about water. The National Park Service's brief on repairing historic wooden windows says that before any repair, every source of moisture penetration should be found and eliminated. The same principle keeps the house sound afterward.

Moving water away from the walls

Most of the rot we repair can be traced to a handful of sources. Each one is cheap to fix compared with the damage it causes, and most can be checked in an afternoon.

If the inspection before your repair named a specific moisture source, start there. It is the one problem you already know about, and it is the one most likely to damage the wood next to the repair if it is left alone. Fix it within a few weeks of the repair, not at some point next year.

• Sprinklers: watch each zone run and adjust any head that sprays the walls, windows or door frames. Around Dallas, sprinklers wet some walls far more often than rain does.
• Gutters: clean them, make sure seams do not drip and that water does not spill over the edge onto fascia and trim.
• Downspouts: send water away from the house rather than letting it splash against posts, steps or siding.
• Soil and mulch: keep them below the bottom of trim, siding, door frames and posts, so wood is never sitting against damp material.
• Plants: trim shrubs back from walls so wood can dry after rain.

Paint, caulk and the shape of the sill

Paint and stain are the film that keeps water from soaking into wood, and they only work when they are intact. The Park Service brief points out that paint blistering, cracking, flaking and peeling usually mark the places where water is getting in. So when you see paint failing on a sill, a jamb or a trim joint, deal with it that season: scrape, prime any bare wood and repaint, and probe first to make sure the wood underneath is firm.

Joints are the other entry point. The brief recommends caulking the joint between the sill and the jamb to reduce water penetration, and checking that the sill slopes away from the building so water drains off. Our repairs restore the slope and the drip edge, but caulk elsewhere on the house ages and opens. Look at every joint around windows and doors each year and recaulk where it has cracked or pulled away.

One caution: do not seal everything shut. A gap that lets trapped water drain out of a joint is doing a job. If you are not sure whether a gap should be caulked, ask before you fill it.

Doors and posts: the spots that fail first

Entry, French and patio doors take water every time rain blows against them, and it runs down the face of the door and the jamb and collects at the threshold. Keep the threshold sealed where it meets the jamb, keep the bottom of the door painted on all sides if you can reach it, and make sure a doormat or planter is not holding water against the frame. If a door starts to drag or stops latching, look at the bottom of the jamb first.

Porch posts and columns fail at the base, where water sits on the porch floor and wicks up into the end grain. Keep the floor around each post clear of standing water and debris, keep the paint at the base intact, and probe the bottom few inches every time you do your walk-around. Deck posts near the ground get the same check, along with the boards and rails that take the most sun.

A twice-a-year walk around the house

Pick two dates, perhaps spring and fall, and walk the outside of the house with a screwdriver. It takes less than an hour on most homes, and it catches problems while they are small. If you are not sure whether what you find is rot or only tired paint, this guide to telling them apart shows how to probe properly.

• Probe the lower corners of every window sill and the bottom of every door jamb.
• Look for new peeling, bubbling or cracked paint, especially on horizontal surfaces.
• Check caulk at window and door joints for cracks or gaps.
• Look at the bases of porch posts, columns and deck posts.
• Check fascia and trim under the gutters after a heavy rain.
• Look inside at window stools and the wall below each window for stains.

Decks and fences need stain on a schedule

Decks and fences take more sun and water than any other wood on the property, and they have no roof overhang to help. Stain is what protects them. On our staining page we recommend re-staining every two to four years, depending on sun exposure and the type of stain. We offer transparent, semi-transparent and solid stains, and all three provide water and UV protection.

Preparation matters as much as the stain. Our staining projects start with power or soft washing, brightening where needed, mold and mildew removal and full drying before any stain goes on. With new wood, we test moisture first; the page notes that is typically four to eight weeks after installation. Most staining projects are finished in one day, and you get maintenance guidance at the end so you know when the next coat is due.

Checking after a hard storm

North Texas storms can bring a lot of water in a short time, plus wind and sometimes hail. After a big one, take ten minutes to look at the places that get hit hardest: gutters that may have overflowed, fascia and trim below them, sills on the wall that faced the storm and any paint that has been chipped or cracked. Fresh damage to the paint film is an open door for water, and touching it up quickly keeps a small issue small.

If a gutter overflowed during the storm, it may be clogged or pitched wrong. A gutter specialist explains what overflowing gutters do to a house in why water spills over the gutter edge, and fixing that protects trim and fascia as much as it protects the foundation.

Your warranty and your records

Every epoxy repair we do carries a ten-year warranty under the Preservan Promise: if the work fails because of workmanship, we fix it. Keep the paperwork, the itemized invoice and the before-and-after photos together with your house records. They show exactly which pieces were repaired and when, which is useful if you ever need to use the warranty and just as useful if you sell the house.

Your own records help too. A phone photo of each repaired area once a year, taken from the same spot, makes it easy to see any change. If something looks different, you will have a clear before picture to compare it with.

If you repaint the house in the coming years, tell the painter which areas were repaired. The repaired sections take primer and paint like the rest of the trim, and a painter who knows where they are can make sure nothing is sanded or scraped more aggressively than it needs to be.

When something looks wrong again

If you find a new soft spot, fresh peeling on a sill or a repair area that does not look right, call sooner rather than later. A small spot caught in its first season is a short repair; the same spot left for two years is a bigger one. For an area we repaired, contact us so we can look at it under the warranty. For new damage elsewhere, we will inspect it for free and send an itemized quote.

It also helps to know which beliefs about rot lead people to wait too long, and I go through them in the myths and mistakes that make rot worse. For the bigger picture of how decay starts and how we repair it, see what rot is doing inside a soft window sill. We serve Dallas and the northern suburbs, including Garland, Rockwall, Wylie, Lucas, Fairview and Celina.

Questions people ask me