The most cost-effective thing you can do for a wood fence or deck — applied at the right time, with the right product, it extends the life of your structure significantly and defers replacement by years.
A properly applied sealer does not just improve appearance — it locks out the moisture that drives rot, slows the UV degradation that breaks down wood fiber, and extends the service life of a structure that would otherwise be on a replacement timeline.
On the Peninsula, untreated wood surfaces face a specific set of adversaries: morning fog that deposits moisture daily, salt air that breaks down wood cell structure and accelerates surface checking, afternoon UV exposure that degrades surface fibers and drives off natural oils, and winter rain that drives moisture into any crack or check that has opened since the last application. Left untreated, a Con-Heart redwood deck will begin checking within one to two seasons, gray to a silver patina within three to five, and develop significant surface checks — water entry points — within five to seven years. That same deck, properly sealed at installation and maintained on the right schedule, can look and perform well at fifteen years and beyond. The difference is not the wood — it is the finish program.
The most important principle in wood preservation is timing. A sealer applied to a sound, clean wood surface penetrates deeply and bonds to the wood fibers. A sealer applied to a surface that has already opened up, checked, and begun to gray bonds shallowly and performs poorly — it sits on a compromised surface rather than penetrating into a sound one. This is why we recommend the first application within six months to one year of installation on new redwood, before the surface has had a chance to open. For existing structures, the question is whether the wood is still a candidate for sealing or whether it has deteriorated to the point where staining will not meaningfully extend its life. We assess that honestly — if a deck is at year twelve with significant structural checking and soft surface fibers, we will tell you that a sealer is a cosmetic improvement rather than a preservation measure, and that a surface replacement evaluation is the more useful conversation.
For decks and fences in the five to ten year range that have been maintained — or even those that have been neglected for a season or two but are structurally sound — a professional cleaning and sealing program can meaningfully extend service life. We use high-solids penetrating oil stains and sealers that are appropriate for the Peninsula's combination of moisture and UV exposure. These are not hardware store sealers — they penetrate deeper, bond more durably, and maintain their barrier properties significantly longer in coastal conditions. The prep work matters as much as the product: proper cleaning to remove oxidation, mildew, and salt residue before application is what allows the sealer to penetrate rather than sit on the surface. A sealer applied over a dirty or oxidized surface is performing at a fraction of its capacity regardless of the product quality.
The right decisions at the right time make the difference between a maintenance program that works and one that wastes money. Here is a direct guide to wood preservation on Peninsula properties.
The simplest way to know whether a wood surface needs sealing is the water bead test — pour a small amount of water on the surface. If the water beads up and sits on top, the existing sealer is still working. If the water absorbs into the wood within a few seconds, the sealer has depleted and the surface is taking on moisture with every rain and fog event. On the Peninsula, where moisture exposure is near-daily, a surface that is absorbing water is actively deteriorating. The water bead test takes thirty seconds and tells you more than a visual inspection alone.
Beyond the water test, visible indicators that sealing is overdue include surface graying (the natural oils that give redwood its warm color have been lost), surface checking (small cracks across the grain that become water entry points), and a rough or fuzzy surface texture (UV degradation has broken down surface wood fibers). Each of these conditions is reversible to some degree with proper cleaning and sealing — but the window narrows as they progress. Surface checking that has opened wide enough to catch debris has become a structural concern, not just a cosmetic one.
Wood sealing requires dry surface conditions and moderate temperatures — the product needs to penetrate and cure without moisture interference. On the Peninsula, the practical window is late spring through early fall — after the winter rains and before the first fall storms. May through September is ideal: the fog burns off by mid-morning on most days, afternoon temperatures are moderate, and the wood has had time to dry from the winter moisture load. We avoid application during the fog season peak — early mornings in June and July — and schedule work for afternoons when conditions are consistently dry.
If structural repair work — post replacement, joist sistering, board replacement — has been done recently, the new wood needs time to dry and stabilize before sealing. New redwood typically needs 60 to 90 days of weathering before the surface is ready to accept a penetrating sealer effectively. We coordinate sealing work as a follow-on scope to structural repairs, scheduled at the appropriate interval after the repair is complete.
New redwood decking and fencing benefit from a first application within six to twelve months of installation. The wood is at its best condition — tight grain, natural oils intact, no surface checking — and the sealer penetrates most effectively at this stage. Many homeowners skip this step and wait until they see visible deterioration; by then the surface has already opened and the sealer is working at a disadvantage. A first application on new wood is the highest-return investment in the structure's long-term life and the easiest one to make.
A properly sealed new structure on a Peninsula maintenance program typically needs reapplication every two to three years for decks and every three to four years for fences, depending on exposure. South-facing and west-facing surfaces in fog-dense cities like Pacifica and Daly City sit at the more frequent end of that range. Protected north-facing surfaces in more sheltered locations like Burlingame or San Mateo sit at the less frequent end. The water bead test at the two-year mark tells you which direction you are tracking.
A deck or fence in the five to twelve year range that has had some maintenance — even inconsistent maintenance — is typically a strong candidate for a professional cleaning and sealing program. The wood has mellowed, surface checks may have begun to open, and the natural oils have partially depleted. A thorough professional cleaning followed by a high-quality penetrating stain can restore significant moisture resistance and extend service life meaningfully. This is the stage where the choice between continued maintenance and replacement is often made — and a professional sealing program frequently shifts that decision by several years.
Structures beyond twelve years that have been neglected require an honest structural assessment before any sealing program is proposed. If the wood is checking deeply, soft to probe, or showing signs of structural compromise, sealing is a cosmetic measure that delays the appearance of failure without addressing the underlying condition. We assess the structure before recommending a sealing program for older wood — if replacement or partial replacement is the better answer, we tell you that directly rather than selling a maintenance service that will not deliver meaningful results.
Penetrating oil stains are the workhorse of professional wood preservation on the Peninsula. Unlike film-forming finishes that sit on the surface and peel when they fail, penetrating oils soak into the wood fiber and bond with the cell structure. They do not peel — they deplete gradually and require reapplication rather than stripping and recoating. High-solids formulations provide the deepest penetration and the longest service life between applications. We specify products designed for the specific moisture and UV profile of coastal Northern California — not inland California or Pacific Northwest formulations that are calibrated for different exposure conditions.
Clear sealers preserve the natural color of the wood and provide moisture and UV protection with minimal pigment. They show the natural grain most completely but provide the least UV protection — UV degrades clear-sealed wood faster than pigmented finishes. Semi-transparent stains add pigment that blocks UV while still showing wood grain and character. Solid stains provide the most UV protection and the most consistent color but cover the grain entirely. For most Peninsula redwood applications, semi-transparent penetrating stain is the right balance — meaningful UV protection while preserving the wood's visual character.
Hardware store sealers — the gallon cans available at any home improvement retailer — are formulated for broad geographic markets and moderate maintenance schedules. They typically have lower solids content, less UV protection, and shorter effective life in coastal conditions than professional-grade products. More importantly, they are often film-forming rather than penetrating, which means they fail by peeling rather than depleting — creating a prep problem for the next application that professional penetrating products do not create. The product cost difference between a hardware store sealer and a professional-grade penetrating stain is marginal; the performance difference in this climate is significant.
Wood cleaners and brighteners are not optional steps — they are what makes the sealer work. A wood cleaner removes oxidation, mildew, and surface contamination. A wood brightener restores the surface pH and opens the wood grain for maximum penetration. Applied together before sealing, they allow the product to perform at full capacity. Applied without them, even the best sealer is working against a contaminated, closed surface. We use professional cleaning and brightening products as standard prep on every sealing job.
A professional cleaning and sealing program on sound wood in good condition produces three outcomes: restored appearance, improved moisture resistance that you can verify with the water bead test, and extended service life. What it does not do is reverse structural deterioration, eliminate existing checks, or restore wood that has lost significant fiber integrity. We are direct about what sealing can and cannot accomplish on any given structure — a disappointed customer is always the result of expectations that were not set correctly at the start.
On Peninsula properties, a professional-grade penetrating stain applied to properly prepared wood typically maintains effective moisture resistance for two to four years on high-exposure deck surfaces and three to five years on fence surfaces with less foot traffic and UV exposure. The water bead test at the two-year mark is the reliable indicator — schedule reapplication when the surface starts absorbing rather than waiting for visible deterioration. Staying ahead of depletion is always less work and less expensive than recovering from neglect.
A cleaning and sealing service typically runs one to two days depending on the scope — cleaning and brightening on day one, sealing application after the surface has dried adequately on day one or day two. We need clear access to the structure and adjacent surfaces need to be protected from overspray. Plants near the fence or deck should be watered and covered. The surface needs to stay dry for 24 to 48 hours after application while the sealer cures — we schedule around the Peninsula weather window to avoid fog events during that cure period.
The most effective approach to wood preservation on Peninsula properties is a scheduled maintenance program rather than a reactive one. We are available for assessment visits to evaluate surface condition and recommend timing, and we work with homeowners on a schedule that fits the specific exposure conditions of their property. A wood structure that is maintained on the right schedule costs significantly less over its life than one that cycles between neglect and emergency repair — and it looks better throughout.
What we hear most before and during a staining and sealing project.
We handle fence repairs, deck board replacements, post replacements, stair and railing repairs, gate adjustments, and retaining wall stabilization. If it’s wood, iron, or masonry and it’s in your yard, we can likely fix it. We assess first and give you a written scope before any work begins.
We give you an honest answer on this at the estimate. A repair makes sense when the structure is fundamentally sound and the failing components are isolated. When rot, post failure, or structural movement is widespread, replacement is usually more cost-effective over a 5–10 year horizon. We’ll show you the math.
Yes. Gate sag is one of the most common repairs we do. Causes include post lean, hinge failure, diagonal brace failure, or the gate itself racking over time. Most gate repairs are straightforward — we diagnose and fix the root cause, not just the symptom.
Push on the post at the base — solid wood doesn’t flex. Probe with a screwdriver near the ground line; if it penetrates more than a quarter inch easily, the post has internal rot. Visible darkening, soft spots, and separation from concrete at the base are also signs. We assess posts as part of any estimate visit.
We do maintenance visits — cleaning, minor repairs, hardware adjustments, and condition assessments. Contact us to discuss what a maintenance schedule looks like for your specific property. Most Peninsula homeowners benefit from an assessment every two to three years.
Yes. Storm damage is a priority situation and we work to schedule assessments quickly. We document damage thoroughly, which also helps if you are filing a homeowner’s insurance claim. Call us directly for storm damage situations.
Free estimates on all fencing, decking, hardscape, and custom build projects across the Peninsula.
