Weatherproofing and exterior maintenance

01 — Protecting windows before a storm

Plywood mounted to the frame protects a window. Tape does not, and post-storm forensic data confirms it.

Window taping is one of the most persistent pieces of bad advice in disaster preparedness. A 2011 survey conducted before Hurricane Irene found that 7 in 10 respondents taped their windows. After Hurricane Wilma made landfall in South Florida in 2005 with sustained winds of 125 mph, post-storm forensic analysis showed that taped windows performed no better than untaped ones. Homeowners who had spent hours applying an X pattern across their glass reported worse interior damage, not less.

The mechanism explains why. When glass breaks under wind pressure without tape, it fractures into small, relatively manageable pieces through what engineers call conchoidal fracture. Tape interferes with that pattern. It holds the shattered pane together for a fraction of a second longer, which lets the window absorb slightly more pressure before failing in one larger, sharper-edged release. The result is fewer but more dangerous shards of glass moving at high speed. FEMA and the Federal Alliance for Safe Homes have both stated plainly that tape provides no structural reinforcement to a glass pane.

Real protection comes from covering the window, not reinforcing the glass itself.

• Pre-cut plywood, 5/8 inch thick minimum. Three-quarter inch is preferred where available. The panel must be anchored into the structural window frame, not into the stucco or siding around it, using lag bolts or permanent barrel bolt brackets rated for the purpose.
• Cut and label panels before storm season, not during it. Measure each window, cut plywood to fit with a small overlap, and label each panel for its specific window. When a storm is approaching, you want installation to take minutes per window, not an afternoon of measuring under pressure.
• Permanent hurricane shutters or impact-rated glass are the more durable long-term investment if you live in a hurricane-prone region and plan to stay in the home. Plywood is a sound emergency measure, not a permanent substitute.
• Garage doors and entry doors need attention too. A garage door is often the largest opening in a home and a common failure point. A rated door or a vertical brace kit closes that vulnerability alongside window protection.

02 — Gutters and the foundation they protect

A clogged gutter does not just overflow. It redirects roof runoff straight down against your foundation, which is exactly where you do not want concentrated water.

Gutters exist to solve a simple problem: a few inches of rain falling on an average roof produces several thousand gallons of runoff, and that water has to go somewhere. When gutters work as designed, they carry it to downspouts and away from the house. When they clog with leaves, seeds, and debris, the water finds the path of least resistance, which is usually straight off the roof edge and down the side of the house into the soil right against the foundation wall.

That soil, known as backfill, is more porous than undisturbed ground because it was excavated and replaced during construction. It absorbs water readily, and repeated saturation right at the foundation creates hydrostatic pressure against the wall. Over time this pressure contributes to seepage, cracking, and in severe cases, structural settlement. In winter, water that backs up in a clogged gutter freezes, forming ice dams that can force water back under roof shingles and into the house through the ceiling.

The fix is straightforward maintenance, done on a schedule rather than reactively.

• Clean gutters at least twice a year. Once after leaves fall in autumn and once after spring pollen and seed debris accumulates. Homes near heavy tree cover may need a third cleaning.
• Extend downspouts at least 4 to 6 feet from the foundation. Building codes commonly require a minimum of 5 feet, and homes with basements or clay-heavy soil benefit from extending to 8 or 10 feet. The extension should discharge onto ground that slopes away from the house, not onto flat or inward-sloping ground.
• Check the slope of the gutter itself. Gutters should pitch slightly toward the downspout, roughly 1/16 inch of drop per foot of run, so water does not pool and freeze inside the gutter trough.
• Watch for sagging sections or pulled-away brackets, which usually mean the gutter is holding more weight than it should, often from standing water or accumulated debris.

03 — Keeping a basement dry starts outside it

Most basement water problems are exterior drainage problems wearing an interior disguise. Fix the grading and the gutters before you reach for sealants.

It is tempting to treat a damp basement as an interior problem and respond with waterproof paint or a dehumidifier. Those measures address symptoms. The underlying cause, in most cases, is water accumulating outside the foundation faster than the soil can absorb or redirect it.

Soil immediately around a foundation should slope away from the house. The commonly cited standard is roughly one inch of drop per foot for the first 6 to 10 feet from the wall, though specific numbers vary by source and local soil type. Clay soils hold water longer and benefit from more aggressive grading and longer downspout extensions than sandy soils, which drain faster on their own. If the ground has settled or been disturbed near your foundation over the years, that slope can flatten or even reverse without anyone noticing until water starts pooling against the wall during heavy rain.

If you have addressed grading and gutters and still see water entering, especially through the lower wall-floor joint or through visible cracks, that points toward groundwater pressure rather than surface runoff, and may need a French drain, an interior perimeter drain system, or evaluation by a waterproofing professional.

04 — Reading a foundation crack correctly

Direction matters more than most people assume. A hairline vertical crack is usually cosmetic. A horizontal crack means the wall is under lateral pressure and needs evaluation.

Concrete shrinks slightly as it cures, and that shrinkage produces thin, straight, vertical or near-vertical cracks in a poured foundation wall. These are extremely common, typically appear within the first few years after construction, and on their own are not a structural concern. The distinction that matters is not just that the crack exists, but what direction it runs and whether it is changing.

Horizontal cracks tell a different story. A wall under lateral pressure, usually from saturated or expansive soil pushing inward from outside, tends to crack horizontally because that is the direction the wall is bending. Horizontal cracking is a more serious signal than vertical cracking and generally warrants evaluation regardless of width.

In block or brick foundations, cracks often follow the mortar joints in a zigzag rather than running straight, producing what is called a stair-step crack. This pattern usually indicates uneven settlement, where one section of the foundation is sinking or shifting relative to another. Stair-step cracks are commonly found at corners and near windows and doors, where the wall experiences the most stress.

For any crack you decide to monitor rather than act on immediately, mark both ends with a pencil and write the date directly on the wall. Measure the width with a ruler or a crack-width comparator card, available cheaply at most hardware stores. Recheck in three to six months. A crack that has not widened or lengthened in that window is behaving as expected for normal cosmetic shrinkage. One that has grown has moved into territory that needs a professional opinion.

05 — Assessing a hazardous tree

The U.S. Forest Service uses what is called the one-third rule: if decay has consumed more than a third of a tree's structural wood, failure risk is considered high.

Trees fail for reasons that are often invisible from the ground, which is why tree risk assessment is treated as a genuine skill with professional certification behind it, not a casual glance. The International Society of Arboriculture defines three levels of assessment, from a quick visual scan to a detailed multi-angle inspection to advanced diagnostic tools. Most homeowners are equipped for something closer to the first level: knowing which signs warrant calling someone qualified to do the second or third.

• Dead or hanging branches, especially over the house, a driveway, or power lines. Dead wood is identifiable by missing bark and the absence of leaves during the growing season. A branch large enough to cause injury, dead and positioned over a target, is a clear action item.
• Fungal growth at the base or along the trunk. Mushrooms, conks, or shelf-like brackets growing on a tree are a visible sign of internal decay that has already progressed. By the time the fruiting body appears on the outside, the fungus has typically colonized a substantial portion of the wood inside, even though the tree may look healthy from a distance.
• Cracks in the trunk, especially vertical cracks on opposite sides of the trunk (a particularly dangerous pattern) or deep cracks that extend well into the wood. These reduce the trunk's ability to bear load and tend to worsen with time and additional stress.
• A new or sudden lean, as distinct from a long-standing one. The Forest Service notes that trees often compensate for a gradual, long-term lean by correcting the upward growth of the trunk above it, which gives the tree an upswept appearance and indicates a root system that has adapted and stabilized. A lean that appears suddenly, particularly after a storm or heavy rain, usually signals root failure and needs prompt evaluation. Disturbed soil at the base, raised on one side, is another sign the root plate has shifted.

06 — Caulking: what it is for and what it is not for

Caulk seals fixed joints under a quarter inch wide. Moving parts, like a door against its frame, need weatherstripping instead.

The distinction the Department of Energy draws is the one that matters most for getting this right: caulk is for stationary components, weatherstripping is for components that move. Around the fixed perimeter of a window or door frame, where the frame meets the siding or trim, caulk is correct. Where the operable part of the window or door actually contacts the frame when closed, that is a moving joint, and caulk applied there will crack and fail as the parts shift against it. Weatherstripping is the right material for that location.

Beyond windows and doors, caulk belongs anywhere two different materials meet and a gap could let in water, air, or pests: where a tub or shower surround meets the wall, around pipe and wire penetrations through walls and floors, and at the foundation sill where the house framing meets the concrete foundation. The Department of Energy notes that an average home needs roughly half a cartridge of caulk per window or door and about four cartridges for the foundation sill, which gives a sense of scale for a full weatherization pass.

Application technique is simple but easy to get sloppy on a first attempt.

• Remove old caulk first. Use a putty knife or screwdriver to clear away cracked or peeling caulk before applying new material. Caulking over failing caulk does not create a reliable seal.
• The surface must be clean and dry. Sealing in moisture defeats the purpose and can encourage mold behind the new bead.
• Cut the cartridge tip at a 45-degree angle. This angle, combined with holding the gun at roughly the same angle to the joint, lets the caulk get pushed into the gap rather than just sitting on top of it as you pull the gun along the seam.
• Smooth the bead with a damp finger every couple of feet as you go, which presses the material into the crack and gives a cleaner finished line. Clean excess immediately; dried caulk is far harder to remove.
• Apply in dry weather above roughly 45 degrees Fahrenheit. Cold temperatures and high humidity interfere with proper curing, which typically takes 12 to 24 hours depending on conditions.
• Replace cracked or peeling caulk annually, particularly around tub and shower edges, where moisture exposure is constant and seals fail fastest.