How to Install Zinc Strips on a Roof

Install zinc strips high on each roof slope, usually tucked beneath the ridge-cap shingles so rainwater can wash over the exposed metal and carry zinc down the roof. Add strips below features that interrupt that water flow and farther down long slopes when your strip maker’s coverage instructions require it. Zinc strips help prevent new moss, algae, mold, and mildew growth; they do not remove growth that is already established.

How Zinc Roof Strips Work

Zinc roof strips are narrow pieces of zinc installed where rain first reaches the roof plane. Rainwater moves across the zinc and carries zinc carbonate down the roofing surface. That residue discourages moss and algae from taking hold on the shingles below.

A strip only protects the roof surface that receives its zinc-bearing rainwater.

That is why placement matters more than simply using a long strip at the ridge. A chimney, skylight, dormer, roof transition, or long slope can leave part of the roof outside the normal runoff path.

Zinc is a prevention measure, not a roof-cleaning treatment. If the roof already has thick moss, dark algae streaks, mold, or mildew, clean that growth first so the strip can help keep the cleared area from becoming established again.

Plan the Zinc Strip Layout Before You Start

Use this quick decision table to decide where strips belong and whether zinc strips suit the roof at all.

Roof Condition	Plan
Moss, algae, mold, or mildew is already present	Clean the affected area before installing strips.
One simple ridge with an uninterrupted slope below it	Start with a strip just below the ridge cap or ridge vent.
Multiple ridges or separate roof sections	Treat each ridge and water-shedding plane as its own layout area.
Chimneys, dormers, skylights, or other interruptions	Place another strip below the obstruction so runoff resumes across the lower roof.
Long roof slope	Use the strip maker’s stated coverage distance to determine whether a lower strip is needed.
Spanish Tile roofing	Do not use Z-STOP zinc strips; the tile shape prevents continuous runoff from the ridge.
Reroofing project	Install strips where their fasteners will be covered by ridge components or upper shingles.
Existing shingle roof	Use properly sealed fasteners so new nail holes do not become leak points.

Before ordering material, measure each ridge and each additional location below an interruption. Include all roof planes that need a separate strip rather than measuring only the house’s main ridge.

How to Install Zinc Strips on a Roof

Zinc strips are installed beneath upper roofing layers so rainwater carries zinc down shingles, with additional strips for obstructions and slopes exceeding about 20 feet.

Step 1: Prepare the Roof and Work Area

Put on work boots, gloves, and protective eyewear.
Check that you can safely go up and down the ladder and remain aware of roof edges.
Have another person present while you work, or hire a roofing contractor if the roof is steep or you are not comfortable working at height.
Clear loose debris from the planned strip locations so the zinc will sit flat beneath the shingles or ridge cap.

Do not install a strip over damaged or loose roofing that needs repair. The strip should be an add-on to a sound roof, not a way to cover a roofing problem.

Step 2: Remove Existing Moss, Mold, or Algae

For its own zinc-strip installation process, ARTA’s zinc-strip instructions use a mixture of 3 parts to every 1 part bleach for existing growth. Brush the mixture over the affected roofing, allow it to sit for about 10 minutes, then brush again to remove remaining residue.

Cleaning products and roof materials vary, so confirm that the cleaner is suitable for your particular roofing before using it. Thick moss can remain physically trapped beneath shingles even after it has died.

Step 3: Mark the Ridge, Obstructions, and Long Slopes

Start at the roof peak. The primary location is at the top of the roof below the ridge cap, ridge vent, or first row of shingles. This placement leaves enough zinc exposed to rain while keeping the upper edge protected beneath the roofing layer.

On a roof with multiple ridges, install zinc strip at the top of each ridge on both sides. Treat a hip roof, intersecting roof, or addition as separate water-flow sections rather than assuming runoff from one ridge will protect another.

Then look downhill from every strip location. Install another strip below any obstruction that blocks normal rainwater flow, including:

Chimneys
Dormers
Skylights
Roof transitions
Wide vents or other raised features

For long slopes, zinc strip is effective for about 20 feet below the strip; add another strip if the distance below it exceeds approximately 20 feet. Other zinc-strip products may have different coverage ratings, so use the installation instructions for the strip you buy when laying out additional rows.

Step 4: Measure, Cut, and Tuck the Strip Into Position

Measure each planned run and cut the zinc to length with scissors or tin snips. Wear gloves while handling cut metal because the edges can be sharp.

A Z-STOP roll is 2-1/2 inches wide by 50 feet long, which can cover a long ridge but may need to be cut into shorter pieces for separate roof planes or locations below obstructions. Measure each section before cutting so the strip reaches across the intended water-flow path.

Starting at one end of the ridge, carefully lift only the roofing layer needed to slide the upper edge of the strip underneath. Tuck the strip beneath the ridge-cap shingles, ridge vent, or uppermost shingles, leaving the lower portion exposed to rainfall.

Keep the strip aligned horizontally across the roof plane. The goal is for rainwater to travel from the zinc directly onto the shingles below, not to bypass the strip through a gap or flow around its end.

Step 5: Fasten the Strip Without Creating Leaks

Secure the strip according to the fastener system supplied or specified by its manufacturer.

For an existing roof, put each nail through a washer or rubber gasket. The gasket seals the new penetration and helps prevent water from entering around the fastener.

For a Z-STOP 50-foot roll, use galvanized neoprene-washer roofing nails approximately every 2 feet. That spacing is specific to the installation guidance; use the fastening pattern specified for another brand or strip design.

When installing zinc strips during reroofing, do not use rubber washers. In that situation, the nails belong beneath the ridge vent, ridge cap, or top row of shingles, where the nail heads will not be exposed to weather.

After fastening, press the lifted shingles or ridge cap back into their normal position. Check that the strip lies flat, the exposed zinc faces downhill, and no fastener head is left exposed unless the manufacturer’s fastening system is designed for that use.

Step 6: Finish the Installation and Check Water Flow

Walk around the house and inspect each strip location from the ground. Confirm that:

Every major ridge has a strip where needed.
Rainwater can run from the exposed zinc onto the shingles below.
Chimneys, dormers, skylights, and other interruptions have a lower strip where runoff would otherwise stop.
Strips on long slopes cover the roof in sections rather than leaving a large unprotected lower area.
Ridge caps and upper shingles sit back in place without obvious gaps or lifted edges.

The roof does not need a coating over the zinc strip. The exposed zinc is the working surface, so covering it with paint, sealant, or roofing cement would interfere with the rainwater contact that makes the strip useful.

Roof Types and Situations That Need Different Planning

Existing Asphalt Shingle Roofs

On an existing asphalt-shingle roof, use the fastener system specified for the strip.

Do not force a strip beneath brittle shingles.

Metal, Wood, Concrete, and Flat Tile Roofs

Check whether a zinc-strip product is intended for your roofing material.

A fastening approach suitable for asphalt shingles may not be appropriate for a standing-seam metal roof or a concrete tile roof, so use a strip system intended for that roof type.

Spanish Tile Roofs

Z-STOP zinc strips are not suited to Spanish Tile roofing. The curved shape prevents rainwater from flowing continuously from the ridge down the roof, which limits the zinc runoff the strip depends on.

Choose a moss-control method that works with the tile profile instead of relying on a continuous strip at the ridge.

Roofs With Limited Rain Runoff

Areas shielded by a higher roof plane, large dormer, or other obstruction need their own strip below that interruption. Roof sections that receive little direct rainfall may not get uniform zinc distribution from a distant ridge strip.

Check the Results and Maintain the Roof

Zinc strips work gradually as rainwater moves across them. They are most useful after the roof has been cleaned and while the strip remains exposed to weather.

Check the roof periodically from the ground for new moss growth, debris buildup, or strips that have shifted out of position. Keep valleys and the area immediately below the strip clear enough for rainwater to travel normally down the roof.

Installed zinc strips can last over 20 years. That is a product-specific durability claim, not a guarantee for every zinc strip or every roof; the strip’s thickness, exposure, runoff pattern, and installation quality all affect service life.

If moss continues to grow in one area while the rest of the roof stays clear, look for a water-flow break above that spot. A chimney, skylight, roof intersection, or long slope can interrupt runoff to that section.

Frequently Asked Questions

How Far Apart Do You Put Zinc Strips on a Roof?

Place strips according to water flow, not as evenly spaced rows across the roof. Zinc strips are intended to protect about 20 feet below the strip, with another strip needed when the slope continues beyond approximately 20 feet. Also add a strip below a chimney, dormer, or skylight when that feature interrupts the runoff path.

How Do You Install Zinc Strips on Existing Asphalt Shingles?

Slide the upper edge of the strip beneath the ridge cap, ridge vent, or top row of shingles, leaving the lower zinc section exposed to rain. On an existing roof, use nails with a washer or rubber gasket to seal each new fastener penetration. Keep the strip flat so rainwater runs over it and down the shingle surface.

Do Zinc Strips Remove Moss That Is Already on the Roof?

No. Zinc strips inhibit new moss, algae, mold, and mildew growth, but they do not remove established growth. A cleaning method uses a 3-to-1 mixture with 3 parts to every 1 part bleach, brushed on for about 10 minutes before brushing away residue.

Which Is Better for Roof Moss, Copper or Zinc Strips?

Neither metal is automatically better for every roof. Both approaches rely on metal-containing runoff moving down the roofing surface, so roof shape, rain flow, compatibility with the roofing material, and installation details matter more than choosing a metal by name alone. Choose a strip system approved for your roof type and install it where runoff can reach the area you need to protect.

Can You Spread Zinc Nitrate Granules on a Roof Instead?

Zinc-strip installation uses continuous pieces of zinc metal placed at runoff points, not loose zinc nitrate granules scattered over shingles. Granules would not create the same controlled, ridge-to-eave rainwater path and may not be appropriate for the roofing material. Use a roof treatment specifically intended for your roof rather than substituting a different zinc compound.

How Do You Waterproof a Zinc Roof Strip?

A zinc moss-control strip is not a waterproof roof covering. Waterproofing comes from correctly lapped shingles, ridge caps, underlayment, and sealed fasteners; on an existing roof, use washer- or gasket-sealed nails where the strip instructions call for them. Once the strips are installed, inspect the ridge area from the ground and address any lifted or damaged roofing promptly.