The window sill gives under your thumb: what wood rot is doing and how it gets fixed

The paint looked fine until you pressed on it

You were washing windows or touching up trim, and the bottom corner of a sill flexed. The paint was intact, mostly, but underneath it the wood was soft, a little damp, and when you pushed harder a piece came away in your hand like wet cardboard. Maybe it is a door jamb at the bottom hinge, or the corner of a garage door frame, or a stretch of fascia under a gutter. Somebody has already told you that the only real fix is to tear it out and replace it, and if it is an original wood window in an older Dallas neighborhood, that quote was alarming.

I am Ben Henderson, owner of Preservan Dallas. Our team repairs rotted wood in place with structural epoxy, keeps the original windows, doors and trim, and finishes the repair so you cannot find it afterward. We do not sell replacement windows or doors, which means we have no reason to tell you that you need them. This guide is what I would show you if I were standing at that sill with you.

What rot actually is, and why it shows up where it does

Wood rot is fungal decay, and the fungus needs one thing above all: moisture held in the wood long enough for it to grow. Dry wood does not rot. That is why rot appears in predictable places: the horizontal surfaces where water sits, the bottom ends of vertical boards where water runs down and collects, the joints where two pieces meet and the caulk has opened, and anywhere a gutter overflows, a sprinkler hits, or soil and mulch touch the wood. Paint slows water down, but once it cracks at a joint or an end grain is left exposed, water gets in and the paint on top traps it there.

In the Dallas area the pattern is sharpened by the climate. Heavy rain arrives suddenly and in quantity. Long hot stretches bake the exterior and open up joints and paint. Sprinkler systems run against the house for months. Older homes with original wood windows, especially in neighborhoods built before vinyl and composite were common, have decades of paint layers hiding the first signs. The rot has usually been working for years before the sill gives under a thumb.

It matters to understand this because the repair has two halves. Fixing the wood is one. Fixing the water is the other, and a beautiful repair under a gutter that still overflows will be a soft sill again in a few seasons.

• Window sills and the bottom rails of sashes, where water sits
• Bottom ends of door jambs, brick mold and garage door frames
• Fascia and soffit under gutters that overflow or leak at seams
• Trim joints where caulk has cracked or pulled away
• Deck and porch posts, stair stringers and anything touching soil
• Siding or trim hit by sprinklers or splashed from hard surfaces

How to check the extent yourself

Take a flat screwdriver or an awl and probe gently along every piece of exterior wood, concentrating on the places listed above. Sound wood resists and the tool skates off. Rotted wood lets the tip sink in with little pressure, sometimes without breaking the paint. Mark each soft spot with a piece of tape. You will usually find that the damage spreads beyond what is visible, most often along the grain and toward the nearest joint or end.

Then look for the water. Stand outside during a rain or run the hose along the gutter and watch where it goes. Look at the sprinkler heads nearest the damage and see whether they spray the house. Check for gaps where the sill meets the siding or the jamb meets the threshold. Inside, look for staining on the window stool or the drywall below, which suggests water is getting past the window rather than only sitting on the sill.

Finally, look for the thing that is not rot. Small round holes, fine sawdust or mud tubes along the foundation are signs of insects. We repair wood that was damaged by termites in the past, but an active infestation has to be treated by a licensed pest professional first, and that is true for any repair company you call.

When it can wait and when it is costing you daily

A single soft spot on a sill, with sound wood around it and no water getting indoors, can wait a few weeks or through a dry stretch while you get it looked at. Prime any bare wood in the meantime so it stops absorbing water. A door that still closes and seals, with softness only at the bottom few inches of the jamb, is similar.

It cannot wait if water is reaching the interior, if the softness extends into a structural member such as a header, a post or a stringer, if a door or window no longer closes properly, or if the damage is under a gutter that is still overflowing. Every storm adds to the repair, and rot that reaches framing changes the scope and cost entirely. If you are selling a house and an inspection report has flagged wood rot, the same applies: the longer it sits, the larger the item becomes in the negotiation.

How we repair rotted wood without removing it

Our process has three stages. The first is diagnosis. A technician inspects the wood, probes for the true extent of the decay, identifies the moisture source and gives you a written scope of work with recommendations. That document tells you what will be repaired, what if anything genuinely needs replacing, and what should change so the water stops. The second stage is preservation. We remove the decayed material down to sound wood, using dust extraction to keep the site clean, then rebuild the missing section with Everesin, a marine-grade structural epoxy that bonds chemically to the wood, cures without shrinking and becomes a permanent part of the piece. It is not a wood filler. We are the exclusive supplier of this product, and it is the reason we can guarantee the repair for ten years.

Once the epoxy has cured, we shape it to match the original profile. A sill gets its slope and its drip edge back; a piece of brick mold gets its exact molding detail; a sash rail gets its proper edge. This is where craft matters, because a repair you can see is a repair that failed its second purpose. The third stage is protection. The rebuilt area is primed and painted in a color matched to the existing finish, the site is left clean, and you receive before-and-after photos and the warranty documentation.

Most projects are finished in one to three days, some in as little as 48 hours, including paint. Along the way we also handle preventive treatment of wood that is sound but exposed, and we stain and wash decks and fences. Our products are eco-friendly and pet safe, and the company is licensed and insured.

• Inspection, probing and a written scope that names the moisture source
• Decayed wood removed to sound material with dust extraction
• Section rebuilt with Everesin structural epoxy, chemically bonded and shrink-free
• Profile shaped to match the original sill, molding or sash detail
• Primed and painted in a matched color; before-and-after photos provided
• Ten-year guarantee on the epoxy repair

What drives the price of a rot repair

The main driver is the extent of the decay, which is why we probe before we quote. A small sill corner is a different job from a sill that is soft across its full length plus the jamb legs on both sides. The number of locations matters, since each one is diagnosed, repaired, shaped and finished. Height and access matter too: second-story windows and tall fascia take ladders or lifts and more time. Complex molding profiles take longer to recreate than flat trim.

Against those factors, in-place repair is generally far less expensive than replacing a wood window or door, and our company cites savings of up to ninety percent compared with replacement in many cases. It also avoids the costs that replacement drags with it: interior trim, drywall, paint and the loss of original character that matters in older homes. We do not publish prices because the honest number comes from the probe, and you receive it in writing after the assessment.

Choosing a repair company, and what to ask about the quote that said replace

If the first person you called sells windows, the recommendation to replace is not dishonest, but it is not neutral either. Ask any company whether they repair or replace, what material they use for repairs and how long they guarantee it. Ask whether they will give you a written scope that identifies the moisture source, because a repair that ignores the water is a short-term fix. Ask to see photos of finished repairs on molding profiles like yours.

Ask about the product directly. Ordinary wood fillers and some two-part fillers shrink, crack and separate from the wood as it moves with the seasons; a structural epoxy designed for this purpose does not. Ask whether they are licensed and insured. And ask how long the work takes and whether painting is included, because a repair left in primer for a month is a repair that is already weathering.

• Repairs rather than sells replacement windows and doors
• Structural epoxy, not filler, with a stated guarantee period
• Written scope that identifies and addresses the moisture source
• Photos of completed work on comparable profiles
• Licensed and insured, with painting included in the job
• Realistic timeline given in days, not weeks

The mistakes that bring the rot back

Filling the soft spot with hardware-store filler and painting over it, which hides the damage while the rot continues underneath and makes the eventual repair larger. Caulking over a gap that was actually letting trapped water out. Painting over wet wood. Leaving the sprinkler head pointed at the house after the repair is done. Replacing a rotted original window with a new unit and leaving the rotted frame around it in the wall.

The most common one is simply waiting for the next quote, then the next season. Rot does not pause while you decide. If the probe went in easily today, it will go in further next spring.

What happens once you schedule an assessment

You request an assessment through our website or by phone and tell us what you have found and where. A technician visits, probes every suspect area including the ones you did not notice, identifies where the water is coming from and writes a scope of work with a price. You decide, with no pressure from us to replace anything. If part of the damage is beyond repair, the scope will say so plainly.

On the scheduled days our crew repairs, shapes, primes and paints, cleans up, and sends you before-and-after photos through the homeowner portal along with your ten-year warranty. We serve Dallas, including Uptown, Oak Lawn, Lakewood, Bishop Arts and Deep Ellum, and the northern suburbs from Addison and Richardson through Plano, Frisco, Allen, McKinney, Garland, Rockwall and Wylie. The window that gave under your thumb will be solid again, and it will still be your window.

Questions people ask me