# FAQ — Siding — Renovate Guide **Author:** Frank Mercer, Licensed GC (Ret.) | HAAG Certified Roof Inspector **Q: How much does it cost to replace vinyl siding on a 2,000 sq ft house?** **A:** Budget $8,000–$16,000 for a full vinyl siding replacement on a 2,000 sq ft home. That breaks down to $4–$8 per square foot installed. Mid-grade .044" Dutch lap panels with standard trim land around $10,000–$12,000. Premium .046"+ insulated vinyl pushes toward the top of that range. Labor runs $1.50–$3.00 per sq ft depending on your market and how much old siding tearoff is involved. --- **Q: How long does vinyl siding last?** **A:** Quality vinyl siding lasts 30–40 years when properly installed. Budget-grade panels under .040" thickness start fading and warping in 15–20 years. The big killers are improper nailing (nailed too tight causes buckling), inadequate overlap, and direct heat sources like a grill or dryer vent against the wall. Manufacturers like CertainTeed and Alside back their premium lines with lifetime limited warranties, but that warranty is voided fast by installation errors. --- **Q: What is the difference between James Hardie and LP SmartSide?** **A:** James Hardie is fiber cement — cement, sand, and cellulose fiber. LP SmartSide is engineered wood — strand wood composite with resin binders. Hardie is harder, more fire-resistant (Class 1/A rated), and holds paint longer — 15-year color warranty on HardieColor products. LP SmartSide installs faster, is lighter (easier on framers), and handles impact better. Hardie wins in fire-prone or high-humidity climates. LP wins where speed and cost matter — LP typically runs $0.50–$1.00 per sq ft less installed than Hardie. --- **Q: How do I know if my siding needs to be replaced or just repaired?** **A:** Walk the perimeter and look for these non-negotiable replacement triggers: rot or soft spots behind the siding when you press it, widespread warping or buckling across more than 20% of the wall, visible gaps at butt joints that you can't close, and water stains or mold on interior walls directly behind the siding. Isolated cracks, one or two broken panels, or fading alone are repair territory. If more than 25% of panels are compromised, full replacement is almost always cheaper long-term than chasing repairs. --- **Q: What is the cheapest siding option for a house?** **A:** Vinyl siding is the cheapest installed option at $4–$8 per sq ft. If you're truly budget-constrained, T1-11 plywood siding runs $2–$4 per sq ft installed but has a short lifespan without diligent repainting. Aluminum siding is largely discontinued for new installs but cheap if you find a contractor still running it. Don't confuse cheapest upfront with cheapest over time — vinyl at $6/sq ft installed that lasts 35 years beats a cheap wood product you're repainting every 5 years. --- **Q: How much does James Hardie siding cost per square foot?** **A:** James Hardie HardiePlank installed runs $10–$18 per square foot depending on your region, the product line, and site complexity. Material alone for HardiePlank Lap is $0.80–$1.20 per linear foot. Labor is where costs climb — Hardie requires shears or a fiber cement blade, is heavy, and needs specific fastener schedules. A 2,000 sq ft house typically runs $18,000–$28,000 fully installed with trim, flashing, and caulking. Get three bids and verify contractors are Hardie Preferred — it affects your warranty. --- **Q: Can vinyl siding be installed over existing siding?** **A:** Yes, but only if the existing siding is structurally sound and flat. You cannot install vinyl over rotted wood, severely warped surfaces, or more than one existing layer. The wall needs to be within 1/4" flat over 10 feet or the new siding will telegraph every imperfection. Before overlaying, inspect every piece of existing siding for soft spots, check all window and door flashing, and add continuous foam insulation backer (3/8" or 1/2" fanfold) to create a flat nailing surface and improve R-value. Skipping this step is the number one cause of callback jobs. --- **Q: What thickness vinyl siding should I buy?** **A:** Don't buy anything under .040" for a residential installation. Here's the breakdown: .040" is entry-level builder grade; .044"–.046" is mid-grade and the sweet spot for most homeowners; .048"+ is premium and noticeably more rigid. Insulated vinyl (foam-backed) ranges .040"–.048" on the face panel but adds R-2 to R-4 per inch of foam. For coastal or high-wind areas, go .046" minimum and verify the panel carries a wind rating of at least 110 mph. Thin panels dent, fade, and warp first. --- **Q: How long does it take to install siding on a house?** **A:** A crew of three experienced siding installers will complete a typical 2,000 sq ft house in 5–10 days. Vinyl goes fastest — a good crew can hang 1,200–1,500 sq ft per day. Fiber cement slows down significantly — figure 600–800 sq ft per day due to the cutting process and weight. Add 1–2 days for tearoff if you're removing existing siding, and another day for trim, j-channel, and detail work around windows and doors. Weather holds things up — you cannot install fiber cement in rain or below 40°F. --- **Q: What is the best siding for a house in a hurricane zone?** **A:** For hurricane zones, fiber cement is the best all-around choice. James Hardie and Allura products carry Miami-Dade and Florida Product Approvals when installed to spec. Vinyl can be used but must be rated for 130+ mph winds — look for ASTM D3679 compliance and verify the specific panel is on the approved product list for your county. Impact resistance matters too — fiber cement won't dent from wind-driven debris like vinyl will. Whatever product you choose, the installation method (fastener type, overlap, flashing) determines whether it survives, not just the panel itself. --- **Q: Why is my vinyl siding buckling and wavy?** **A:** Buckling is almost always an installation error — the panels were nailed too tight. Vinyl expands and contracts up to 5/8" per 12-foot panel with temperature changes. Every nail needs to be centered in the nail slot with 1/32" of clearance between the nail head and the siding — you should be able to slide the panel left and right by hand after nailing. Other causes: panels installed in cold weather without accounting for expansion, panels cut too tight into j-channel, or direct heat sources nearby. If it's widespread, the job was done wrong and needs to be re-nailed. --- **Q: How do I repair a cracked or broken vinyl siding panel?** **A:** You need a zip tool (siding removal tool), which costs $10 at any hardware store. Slide it along the bottom edge of the panel above the damaged one to unhook the locking channel. Lift that upper panel, then remove the nails from the damaged panel using a flat bar. Slide the new panel in, nail it with 1/32" clearance in the slot centers, then re-lock the upper panel. The hardest part is matching color — bring a piece of the old siding to the supplier. UV fade makes exact matches almost impossible on siding over 5–10 years old. --- **Q: What is fiber cement siding made of?** **A:** Fiber cement is a mixture of Portland cement, sand, and cellulose wood fiber, typically compressed and cured under heat and pressure. James Hardie's formula runs roughly 50% cement, 40% sand, and 10% cellulose fiber. The result is a panel that won't rot, won't burn, won't be eaten by insects, and holds a paint finish longer than wood. The downside is weight — HardiePlank 5/16" runs about 1.7 lbs per sq ft, roughly 4–5x heavier than vinyl — and it's brittle under impact at corners. It also requires moisture management details at all cut ends or it will absorb water and fail prematurely. --- **Q: Does new siding increase home value?** **A:** Yes, and the data is consistent. Remodeling Magazine's Cost vs. Value Report consistently shows vinyl siding replacement recouping 67–80% of project cost at resale. Fiber cement returns slightly higher — around 86–90% in most markets — because buyers perceive it as a higher-quality material. The real value driver isn't the product, it's removing failing siding before it causes buyer concerns during inspection. A house with visibly deteriorating siding negotiates down fast. New siding also reduces buyer requests for credits, which is money directly in your pocket. --- **Q: How do you install LP SmartSide siding?** **A:** LP SmartSide requires a weather-resistant barrier underneath — housewrap or building paper minimum. Panels need 6" clearance above grade and 1" above rooflines to prevent moisture wicking. Fasten with hot-dipped galvanized or stainless nails — never staples, never smooth shank. Nail 3/4" from panel edges, 6" on center along bottom edge. Maintain 1/8" gap at all butt joints and caulk with LP-approved elastomeric sealant — no exceptions on that step. All field cuts must be primed with LP Field Priming Sealer immediately after cutting or you void the warranty and accelerate edge failure. Paint within 180 days of installation. --- **Q: What is the difference between horizontal and vertical siding?** **A:** Horizontal siding (lap siding) is the standard — each panel overlaps the one below and sheds water naturally with gravity. It's easier to install, widely available in all materials, and preferred by most building codes for standard residential construction. Vertical siding (board and batten or V-groove panels) requires a solid nailing surface or horizontal furring strips every 24" for proper backing — you can't run vertical panels directly to studs at standard 16" spacing without adding nailers. Vertical siding reads as more contemporary or farmhouse depending on the profile. Water management is trickier — joints must be properly caulked or battened to prevent infiltration. --- **Q: How do you know if there is rot behind vinyl siding?** **A:** Press firmly on the wall surface every 2–3 feet around windows, doors, corners, and anywhere you see discoloration or soft spots. Rot behind vinyl feels spongy or gives under hand pressure. Pull back a J-channel or end cap at a corner and probe with a screwdriver — if it sinks in without resistance, you have rot. Also check the base of the wall at grade line and along any roof-wall intersections. Water almost always enters at flashing failures, window corners, and penetrations, so concentrate your inspection there first. Don't buy a house with vinyl siding without pulling at least 3–4 panels in suspect areas. --- **Q: What is the best paint for wood siding?** **A:** 100% acrylic latex exterior paint. Don't let anyone talk you into oil-based paint for wood siding in 2024 — it cracks and peels as the wood moves seasonally and doesn't flex. For bare or repaired wood, prime with a high-solids acrylic primer like Sherwin-Williams Exterior Oil-Based Wood Primer or Benjamin Moore Fresh Start 100%. Topcoat with two coats of Sherwin-Williams Emerald Exterior or Benjamin Moore Aura Exterior — both carry 10-year warranties. Proper prep is 80% of the job: scrape all loose paint, sand, fill cracks with paintable caulk, prime all bare wood. Skipping prep guarantees failure in 3–5 years regardless of paint quality. --- **Q: How much overlap should vinyl siding have?** **A:** Vinyl siding panels need a minimum 1" overlap at butt joints where two panels meet end-to-end. Most manufacturers spec 1"–1-1/4". In cold climates, go 1-1/4" because panels will contract more in winter. The vertical overlap at butt joints should always be oriented so the lapped end faces away from the primary view angle of the house —