Why is my vinyl siding buckling? What buyers can do

Why is my vinyl siding warping?

Vinyl siding buckles when something stops it moving with the weather. Check the nails first. The Vinyl Siding Institute's manual says "Tight nailing, screwing, or stapling will cause the vinyl siding to buckle with changes in temperature." Have a siding contractor open the panel and price the fix, then ask the seller to fix it or credit you the bid.

Key takeaways

• Each nail needs a dime's thickness of play, because a 12 foot 6 inch panel can move half an inch or more.
• Warping near a window can come from reflected sunlight, and new panels in the same beam can warp again.
• Faded vinyl is hard to match, so use a contractor's bid, not a national average.

How do you fix buckled vinyl siding, and what does it cost?

To fix buckled vinyl siding, a contractor replaces the panel the way the Vinyl Siding Institute's manual shows. The panel above is unzipped with a zip tool, the nails come out, and a new panel is locked on and nailed with proper clearance. Heat-warped siding is different. Fixr says the only repair is to replace the affected planks, and new planks in the same spot are also in danger of warping.

Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote.

Say the report flags two buckled sections of that size on the south wall, 200 square feet in all. At Fixr's per-section price, two sections come to $300 to $600. At HomeAdvisor's per-foot price, 200 square feet comes to $400 to $800. Neither figure covers a damaged barrier behind the panels or blocking a reflected beam, so those go on the contractor's bid.

Color can push the price up. HomeAdvisor notes that vinyl fades in the sun, so matching it "can pose challenges and further increase labor costs." A siding contractor's written bid, after seeing the wall and the color, is the number to use. How to get repair estimates during the inspection period covers getting one before your deadline.

What causes vinyl siding to buckle?

Vinyl moves a lot. The manual says a panel can expand and contract half an inch or more over a 12 foot 6 inch length through normal seasons. Anything that pins it in place makes it bow. The manual names these installation mistakes:

• Nails driven tight. Each fastener should leave about 1/32 inch, the thickness of a dime, between its head and the panel.
• Nails driven crooked. Fasteners go in straight and level "to prevent distortion and buckling of the panel."
• No gap at trim. Panels need at least 1/4 inch of clearance at openings and stops.
• Floor-plate compression. In new construction, it can buckle siding where the floor meets the wall.
• Face-nailing. Nails through the face of the panel instead of the nail hem "can result in ripples in the siding."

Heat can do it too. Low-emissivity (low-E) windows, on your house or a neighbor's, can concentrate sunlight. That beam can create enough heat to melt the siding surface, according to the Polymeric Exterior Products Association, the siding trade group. It says this is not common. It also says the risk can change if nearby windows are replaced.

If your report also flags hardboard or LP siding, that's a different material with a different record; see masonite or LP siding on an inspection report.

Is buckled vinyl siding a serious problem?

How serious buckled vinyl siding is depends on the wall behind the panel. The manual says vinyl is a cladding, not a water-resistive barrier. It must go over a barrier meant to stop water that gets behind the siding from "further intruding into the exterior wall assembly."

So ask the contractor to check two things once the panel is off: whether it was fastened to the Vinyl Siding Institute's rules, and whether the barrier behind it is intact. A torn or missing barrier turns a siding line into a wall line, and the bid should say so.

If the warping sits in a window's reflection, the fix has to block the beam too. The association suggests sunshades, screening on the window, or planting between the window and the wall. The same group says damage from concentrated sunlight is not normally covered by siding warranties, so check the manufacturer's terms before you count on one.

What should I ask the seller for?

Ask for one of two things, in writing:

• The repair, by a siding contractor: replace the buckled panels with proper fastener clearance, and repair any damaged barrier behind them. Ask for the invoice before closing.
• A credit equal to your contractor's written bid, so you choose who does the work.

Name the wall, the scope and the trade on the line, and put the bid behind the number. If the cause is reflected sunlight, have the bid include blocking the beam. What to ask for after a home inspection shows how this fits with the rest of your list, and the buyer repair request letter template gives the wording.

What if the seller says no?

If the seller says no, you still have a known cost: a buckled panel with a written bid. Decide whether you'd pay it yourself for this house. If the contractor finds a damaged barrier or wet sheathing, the scope grows, so get that priced too before you decide. When to walk away after a home inspection covers when an unknown cost justifies leaving. Your contract sets the deadline and terms for your request, so confirm the dates with your agent.

Is it okay if my vinyl siding is a little warped?

Whether a little warped vinyl siding is okay depends on whether the panel still moves. The manual's first rule is that installed panels "must move freely from side to side." If a tight nail is holding it, it will keep buckling as temperatures change. Ask the contractor to check.

What is the average lifespan of vinyl siding?

InterNACHI's life expectancy chart lists vinyl siding at 60 years. It adds that life varies with usage, weather, installation, maintenance and quality of materials. Buckling from tight nails is an installation fault, so it says nothing about the siding's age. Check the seller's disclosure for when the siding went on.

How do I know what my repair list is worth?

Your repair list is worth what its lines cost to fix, and the siding is one line. The rest of the report, from the other exterior findings inward, needs numbers too.

If the siding is one finding among many, upload your inspection report to Kept and spend your remaining days on the contractor's bid for the wall.

Sources

• Vinyl Siding Institute, Vinyl Siding Installation Manual
• Polymeric Exterior Products Association, Solar Reflection
• InterNACHI, Standard Estimated Life Expectancy Chart for Homes
• Fixr, Vinyl Siding Repair Cost
• HomeAdvisor, Siding Repair Cost