Can You Put New Siding Over Old Siding?

What "siding over siding" means

Installing over existing siding (an overlay or re-side without tear-off) means attaching new siding on top of the old, sometimes with foam insulation board or furring strips in between. It was common in past decades, which is why some Wichita-area homes have vinyl over aluminum or vinyl over original wood lap siding. Today it still happens, mostly with vinyl and steel, but less often with heavier products like fiber cement.

When it can work

• The existing siding is flat, firmly attached and dry, with no rot behind it.
• The new product's manufacturer allows installation over existing siding, and the method meets its instructions.
• Window and door trim can be extended so the new siding fits properly around openings.
• The added thickness does not cause problems at roof lines, soffits, decks or the foundation.
• The old siding is not a hazardous material that should be removed or left undisturbed in a specific way.

Why most contractors prefer tear-off

You cannot see what is behind it

The biggest reason. Old siding can hide rotted sheathing, damaged sill plates, insect damage or missing flashing around windows. Covering it locks those problems in. Tear-off lets the contractor inspect and fix the wall before closing it up.

Moisture gets trapped

Two layers of siding can create pockets where water gets in and cannot dry. A modern water-resistive barrier and proper flashing work best directly on the sheathing, which is easiest with a tear-off.

Uneven walls show through

Waves, bulges and loose boards in the old siding telegraph through new vinyl. Furring strips can help, but they add cost and labor.

Windows and trim get awkward

Extra thickness can bury window frames and make trim look recessed. Fixing that means extending jambs or adding new trim, which eats into the savings.

Warranties and fasteners

Some products require installation over sheathing, not over old siding, and fasteners must reach solid framing or sheathing. Nailing through old siding can make that harder and can affect warranty coverage.

Weight

Fiber cement is heavy and usually not installed over existing siding.

Special cases on older Wichita homes

Asbestos-cement siding

Many 1920s to 1970s houses have asbestos-cement shingles. The EPA says material in good condition is generally best left undisturbed, and removal should be done by trained professionals. Covering it is sometimes an option, but nailing through it can damage it, and removal may be required if it is broken. See old asbestos and aluminum siding replacement.

Aluminum siding

Aluminum is thin and often flat enough to cover, but dented panels and the old trim can complicate an overlay. Removal is usually straightforward, and the metal can be recycled.

Lead paint

Wood siding and trim on pre-1978 homes may have lead paint. Covering it avoids disturbing paint, which is one reason some homeowners choose an overlay, but repairs that cut or sand painted surfaces still fall under the EPA's lead-safe rules.

Hail damage

After a hail claim, insurers typically pay to remove and replace damaged siding, and adjusters may write tear-off into the estimate. Ask your adjuster and your contractor how they are approaching it.

Cost: is it really cheaper?

Skipping tear-off saves removal and disposal labor. HomeGuide's published guide lists old siding removal at roughly $0.70 to $2.00 per square foot, nationally (a published estimate, not a quote). But extending window trim, adding furring and dealing with uneven walls can eat into that savings, and the hidden-damage risk does not go away. The cost guide has more on removal.

Permits and code

A re-side over existing siding is still a re-side. In Wichita and other areas served by MABCD, replacing more than 400 square feet in 12 months needs a siding permit whether or not the old siding comes off. See does siding need a permit in Wichita?

Questions to ask a contractor

• Do you recommend tear-off or overlay for my house, and why?
• Does the manufacturer allow this product over existing siding?
• How will you handle window and door trim?
• What happens if you find rot during tear-off? How is it priced?
• Will you install a new water-resistive barrier?
• How will you handle asbestos-cement or lead-painted materials, if present?

What a tear-off day looks like

On a typical tear-off, the crew removes one wall or section at a time so the house is not left open, inspects the sheathing, replaces damaged pieces, installs house wrap and flashing, and then hangs the new siding. Old material goes into a dumpster or trailer, and nails are picked up with magnets. Ask how the contractor protects landscaping, air conditioners and windows during removal, and what happens if rain moves in mid-job.

The bottom line

Overlay can work for sound, flat walls with a product that allows it. For most homes, especially older ones and those with any sign of moisture, tear-off is the safer path. A good contractor explains the choice for your specific walls. See siding replacement to request free quotes.

Related services

• Siding Replacement: Tear off worn or damaged siding and re-side the house in vinyl, fiber cement, engineered wood or steel.
• Old Asbestos & Aluminum Siding Replacement: Replace aging asbestos-cement, aluminum, hardboard and T1-11 siding with the right precautions.
• Siding Installation: New siding for additions, new builds, garages and shops, installed to the manufacturer's instructions.

Sources: HomeGuide, house siding cost; EPA, protect your family from exposures to asbestos; EPA, Renovation, Repair and Painting (lead-safe) program; Wichita-Sedgwick County Unified Building and Trade Code (permit exemptions).

Good to know: Requesting a quote is free and there is no obligation. Ask for a written quote that lists the material, the scope, permits and the warranty terms.