How long does vinyl siding last?

Vinyl siding lasts for decades. The National Institute of Standards and Technology's 2007 life-cycle model assumed a useful life of 40 years for vinyl siding, and noted that many manufacturers provide warranties of 50 years or longer.^[1] It also noted that no routine maintenance is required to prolong its life, although cleaning is recommended to keep its appearance.^[1] In practice, the number that matters is how well your siding was installed and how much sun, heat and knocking about it takes.

What the warranty really tells you

Siding warranties are the best written measure of what a maker expects, but read the terms. Alside's lifetime limited warranty, as an example, lasts as long as the original owner lives in and owns the house,^[2] and can be transferred once, to the next owner, as a 50-year warranty prorated from the original installation date.^[2] For that prorated warranty, the coverage falls from 100% for up to 5 years to 50% at 10 years and 10% from 14 to 50 years.^[2]

What it covers is narrow. It covers blistering, corroding, flaking and peeling caused by manufacturing defects,^[2] and separately covers fading of more than 4 Hunter units of Delta E, a measured colour change.^[2] It does not warrant installation nor defects caused by installation,^[2] and it excludes normal weathering, impact from foreign objects, mildew, structural defects and warping from unusual heat sources such as grills, fire and reflection from windows.^[2] Keep the paperwork: a claim needs proof of purchase and of ownership.^[2]

What wears vinyl out

Sun and weather. Colour fades and the surface dulls over the years. Alside's warranty puts it plainly: "Normal weathering may cause any surface to oxidize, chalk or accumulate surface dirt or stains" depending on sunlight, weather and the air.^[2]

Heat. Vinyl softens when it gets too hot. The same warranty excludes damage from heat building up above 160°F on the panel surface,^[2] whether from sun reflected off windows or from a grill parked too close. See why vinyl siding buckles.

Impact. Mowers, thrown stones, ladders and hail crack panels. Alside covers hail damage for replacement materials only, after the homeowner first goes to their insurance.^[2] A cracked panel is a quick repair: how to replace a damaged piece of vinyl siding.

The installation. Installers are told that panels must move freely from side to side and that nails must not be driven tight.^[3] Tight nailing and missing expansion gaps show up as waves as the seasons change.

Water behind it. Manufacturers call for vinyl siding to be installed over a continuous water resistant barrier to stop the intrusion of incidental water.^[3] The house wrap, flashing and sheathing behind it do the waterproofing, so a loose panel, a missing piece of J-channel or a gutter that dumps water against the wall can rot the wall while the vinyl looks fine.

The wrong care. Alside's warranty does not apply to siding that has been painted or coated over the original finish unless the maker authorizes it,^[2] and becomes void if harmful cleaning compounds are used.^[2]

How to keep it going

Most of the care is a hose and a soft brush. Alside says rainfall is usually enough to wash vinyl, with a periodic rinse from a garden hose where rain does not reach.^[2] For a deeper clean it calls for a soft-bristled, long-handled brush, and warns that rubbing hard can leave glossy patches.^[2]

• The cleaning mix: 1/3 cup powdered detergent and 2/3 cup household cleaner in 1 gallon of water.^[2]
• For mildew: substitute 1 quart of laundry bleach for 1 quart of the water,^[2] and observe the chemical manufacturer's recommended safety precautions with any cleaning agent.^[2] Do not mix bleach with other cleaners.
• Method: start at the bottom and work up to limit streaking,^[2] rinse the whole wall with clear water afterwards, and avoid prolonged or high-pressure rinsing of open, ventilated areas.^[2]
• What to avoid: no cleaners with abrasive particles, solvents or ammonia, and no paint remover.^[2] Rubbing vigorously may create glossy areas over the finish.^[2]

If you are thinking of a pressure washer, read how to pressure wash vinyl siding without damaging it first; green streaks are covered in why siding turns green.

Beyond cleaning, walk around the house once a year. Look for cracked or loose panels, warped spots near grills and windows, gaps where siding meets trim, and gutters or downspouts spilling onto the wall. Keep shrubs trimmed back so walls can dry, and keep a few spare panels from the original job, since replacement panels may differ in gloss and colour from the originals because of weathering.^[2]

Repair or replace?

A few damaged or warped panels are a repair. Replacement starts to make sense when the problems are everywhere: cracking across many walls, siding that has gone brittle or badly faded, panels that cannot be matched, or water damage behind the siding that means it has to come off anyway. If you get to that point, read what new siding costs in Virginia and what to look for in a siding contractor.

Stop and call a pro if

• Panels are damaged above the first storey, where you would need a tall ladder to reach them.
• The wall behind is soft, stained or wet, or you see water damage inside an exterior wall.
• Many panels are warped or wavy, which usually means an installation or heat problem across the wall.
• You are planning to paint the siding and want to keep the warranty; ask the siding maker or a painter who knows its approved coatings.

Find help

Browse siding businesses, find exterior pros around Blacksburg, or read the other exterior answers. If panels need replacing, describe the siding repair once and licensed local businesses will quote it.