Getting Windows Ready for Summer: What the Experts Actually Recommend

This piece draws on guidance from federal agencies — the U.S. Environmental Protection Agency (EPA) and Department of Energy (DOE), which jointly run the ENERGY STAR program, and the Federal Emergency Management Agency (FEMA) — along with the two leading fenestration trade groups, the Fenestration and Glazing Industry Alliance (FGIA, formerly the American Architectural Manufacturers Association, or AAMA) and the National Fenestration Rating Council (NFRC). It also draws on published care guidance from major manufacturers including Andersen, Pella, and Marvin, as well as materials-science sources on coastal aluminum performance.

The baseline: what every window needs before summer

The FGIA/AAMA, working with the Glass Association of North America (GANA), publishes the industry's standard cleaning protocol, which applies to nearly all frame and glass types. The guidance calls for cleaning frame and glass surfaces at least twice a year with mild dish soap and water or a vinegar-based glass cleaner, applied with a soft, lint-free cloth. It explicitly warns against petroleum-based cleaners or solvents, which can streak glass and weaken the seal between glass and frame. In areas with saltwater exposure or acid rain, the group recommends rinsing exteriors and operating tracks with plain tap water several additional times a year. For washing windows specifically, AAMA/GANA guidance recommends testing any cleaning method on one small section first, checking for damage, then moving on to the rest of the window — using a squeegee to remove the cleaning solution and thoroughly drying all sealants, gaskets, and frames afterward.

A seasonal walk-around should also include:

• Weatherstripping and caulk inspection. ENERGY STAR–based guidance recommends checking weatherstripping and caulking every year and repairing wear before it hurts energy efficiency.
• Track and hardware cleaning. Debris in the tracks keeps sashes from sealing properly. Regularly cleaning moving parts helps casement and double-hung windows close securely, which keeps indoor air from leaking out and helps lower utility costs.
• Checking for seal failure. Fogging or trapped moisture between panes of insulated glass signals a failed seal — a repair-or-replace issue, not something cleaning can fix.

Window frames sold in the U.S. today are typically wood (usually clad), vinyl (uPVC), aluminum, fiberglass, or composite blends. Each behaves differently in heat, sun, and humidity, and manufacturers and materials engineers are fairly clear about the distinctions.

Wood and clad-wood

Wood remains prized for its insulating value and looks, but it's the most maintenance-intensive material in summer heat and humidity. Andersen recommends checking wood components — especially around the frame — for rot, cracks, or warping as part of routine seasonal inspection, since these signs can point to compromised structural integrity that should be addressed before it worsens. Most major manufacturers, including Andersen, now sell wood windows with factory-applied exterior cladding — vinyl (Perma-Shield), aluminum, or fiberglass composite — specifically to eliminate the need for repainting while keeping the insulating and aesthetic benefits of a real wood interior. Unclad, painted wood exteriors need more frequent attention: once the paint film fails, moisture gets into the end grain, and once decay fungi take hold, the affected wood shrinks, discolors, and eventually has to be replaced.

Vinyl (uPVC/PVC)

Vinyl is the most common frame material sold today — prized for low cost and low maintenance — but it has the highest rate of thermal expansion of any common frame material. According to materials data cited by manufacturer GEALAN, vinyl's coefficient of thermal expansion is roughly 3.33 × 10⁻⁵ inches per inch per degree Fahrenheit, markedly higher than metal or wood, meaning a 10-foot vinyl frame can shift by as much as a quarter-inch between winter and summer temperature extremes. This is normal physical behavior, not a defect, provided the window was engineered and installed correctly. Darker vinyl absorbs more solar heat — especially on south- and west-facing walls — which significantly increases thermal expansion, while lighter-colored frames stay cooler and more dimensionally stable. Homeowners in hot, sunny climates who want darker frames should look for vinyl with built-in reflective or UV-blocking technology, or acrylic-capstock formulations designed to run cooler.

For upkeep, GEALAN's guidance mirrors AAMA's general standard: clean frames and tracks a few times a year with mild soap and water, and inspect caulking and weatherstripping regularly, especially after extreme temperature swings. Pella's end-of-summer care guidance notes that vinyl, along with wood and fiberglass, expands and contracts with seasonal swings, and recommends watching for warping, cracking, or water damage — particularly after heavy summer storms — since early repairs can head off bigger problems down the line.

Aluminum

Aluminum frames are valued for their slim sightlines and strength, but the metal is highly conductive, so uninsulated aluminum performs worse in extreme heat and cold than other materials unless it includes a thermal break. The Building America Solution Center, a Department of Energy–affiliated resource, describes thermal breaks — strips of non-conductive material separating the interior and exterior aluminum components — as standard on modern products.

Aluminum's bigger summer vulnerability, though, is corrosion, particularly near the coast. Linetec, a finishing supplier that works within FGIA specification standards, explains that salt spray and chloride deposits are among the primary drivers of corrosion on exterior architectural aluminum, and that exposed, unfinished aluminum can develop visible pitting within weeks of chloride exposure — with airborne salt documented more than 50 miles inland from the coast. The industry's benchmark coating standard, AAMA 2605, sets the bar for coastal-grade finish durability: PVDF resin-based coatings that meet it are tested to more than 4,000 hours of accelerated salt-spray exposure for durability against UV radiation, pollution, and weathering. For maintenance, Linetec keeps it simple: aluminum finished with a high-grade PVDF coating or a Class I anodized finish generally needs only a clean-water rinse, or at most a wipe with mild soap and a soft cloth, and should never be cleaned with strong alkaline or acidic cleaners or abrasive scrapers.

Fiberglass

Fiberglass is the newest mainstream frame material and, according to manufacturers, the most dimensionally stable across temperature extremes. Pella describes its fiberglass line as engineered to resist warping, rotting, and swelling from humidity changes, performing consistently across large temperature swings without needing paint or refinishing — it needs only soap and water for cleaning, and resists fading, chipping, and warping over the long term. Because fiberglass expands and contracts at a rate closer to glass than vinyl does, manufacturers argue it holds seals more reliably over repeated seasonal cycles, a claim echoed by the Building America Solution Center's broader frame-material comparisons.

Composite (e.g., Fibrex)

Composite frames — such as Andersen's Fibrex, a blend of reclaimed wood fiber and thermoplastic polymer — are marketed as splitting the difference between wood's insulating value and vinyl's low maintenance. Andersen positions composite cladding this way specifically because it offers stability with minimal upkeep. Its printed care guide warns against practices that could damage the finish, such as using abrasive cleaners or nailing directly through the material, and recommends a plastic scraper for tight seams instead.

Regional differences: climate really does change the playbook

The ENERGY STAR program divides the continental United States into four performance zones — Northern, North-Central, South-Central, and Southern. That federal framework also maps onto some clear, practical regional differences in how windows should be prepared and maintained heading into summer.

The Gulf Coast and Southeast: humidity, storms, and wood rot risk

In the hot, humid Southeast, the dominant seasonal threats are moisture-driven. Industry sources note that wood windows in this region are especially prone to rapid deterioration if maintenance lapses — one window-service company operating in Georgia points to frequent thunderstorms, downpours, and high humidity as reasons wood frames there tend to rot faster than average. This is also the region where hurricane preparedness becomes a building-code issue for windows, not just a maintenance one. FEMA's hurricane mitigation guidance for coastal structures lays out two accepted ways to protect glazed openings: replacing standard glass with impact-resistant glazing rated for hurricane wind pressures and windborne debris, or installing storm shutters securely connected to the wall framing (shutters must be deployed manually, so they require enough lead time before a storm to put up). States such as Florida go further, with statutory requirements: the Florida Building Code requires that all glazed openings be either impact-resistant or covered by an approved impact-rated shutter system, with the toughest standards reserved for Miami-Dade and Broward counties' High-Velocity Hurricane Zone.

Coastal areas nationwide: salt-air corrosion management

Corrosion management isn't limited to hurricane-prone states — it applies to any coastal property, from Long Island to the Pacific Northwest coast to the Gulf. Industry guidance consistently ties rinse frequency to proximity to salt water. One corrosion-focused trade resource lays out zone-based intervals drawn from manufacturer corrosion guides: properties within about 500 meters of the coast should rinse all exposed aluminum with fresh water every three months and inspect seals and weep holes annually, while properties farther inland — up to roughly three miles — can extend rinsing to every six months. A separate coastal-maintenance resource puts the same principle in homeowner terms, recommending monthly fresh-water rinsing of exterior surfaces, including windows, for oceanfront properties, and quarterly rinsing — or rinsing after storms — for properties farther from the water.

The arid Southwest: UV exposure and dry-heat stress

In Arizona, Nevada, and inland Southern California, the main summer concerns shift toward intense, sustained UV exposure and extreme heat rather than moisture. A Pella dealer in Arizona's high country recommends inspecting weatherstripping for heat-related drying and cracking after monsoon season, and checking wood, vinyl, and fiberglass frames for warping tied to seasonal temperature swings. This is also the region where vinyl's thermal-expansion behavior shows up most, reinforcing the manufacturer advice to favor lighter frame colors or UV-stabilized formulations in direct, intense sun.

The North and Upper Midwest: a shorter but still real summer prep window

In colder northern states, ENERGY STAR's framework prioritizes retaining heat, which might suggest summer prep matters less — but the agency treats window upkeep as a year-round discipline, not a seasonal one, since poorly sealed or damaged windows waste energy in both directions. Old, poorly made, drafty, or degraded windows can waste significant energy and cause discomfort during the most extreme weather in either season. In practice, contractors in this region use the mild summer stretch to catch up on caulking, weatherstripping replacement, and glazing repairs before fall — work that's harder to do properly once temperatures drop and sealants stop curing well.

The Pacific Northwest: rain-driven wood rot vigilance

Even though summers are relatively dry in the coastal Northwest, the region's wood windows carry damage that accumulated over the rest of the year, making early-summer inspection an important checkpoint. Regional restoration contractors point to the area's wet climate as the leading driver of wood decay in its building stock: in Portland's damp climate, moisture can seep into siding, trim, windows, and framing, creating conditions where wood-decay fungi take hold — and window frames are especially vulnerable collection points, since rain and moisture tend to pool in these areas. Summer's drier stretch is the practical window to inspect, dry out, treat, and repaint or reseal wood frames before the rains return.

Clean and inspect windows at least twice a year

Federal agencies, standards bodies, and manufacturers converge on a few consistent themes: clean and inspect windows at least twice a year using mild, non-abrasive products; address weatherstripping, caulk, and seal failures promptly; and match both window specification and maintenance routine to the local climate rather than applying a one-size-fits-all approach. Material matters — wood demands the most vigilance against moisture, vinyl needs installation and color choices that account for thermal movement, aluminum requires corrosion management near salt water, and fiberglass and composite materials generally need the least attention. Geography matters just as much: what a homeowner in coastal Florida needs to do before hurricane season looks nothing like what a homeowner in Phoenix or Minneapolis should prioritize, even though all three are, nominally, "getting ready for summer."

Regardless of frame material, ENERGY STAR's residential guidance centers summer prep on two things: sealing air leaks and controlling solar heat gain. Hidden air leaks around windows, doors, and other openings can collectively add up to a hole the size of an open window, and sealing these gaps improves comfort and cuts energy bills. Planting deciduous trees near south-, east-, and west-facing windows is another EPA-recommended strategy, since they shade the home in summer but let sunlight through once they've dropped their leaves for winter.