Click on the questions below for answers to our most common inquiries.

  1. What is Z-STOP?
  2. How does it work?
  3. Is Z-STOP toxic?
  4. How is Z-STOP installed?
  5. Aren't there chemicals that do the same thing?
  6. What kind of roofs will Z-STOP work on?
  7. Won't the shiny strip of Z-STOP be very noticeable on the roof?
  8. Why remove moss or fungus at all?
  9. Which is the problem... moss or fungus?
  10. What about cost?
  11. Is that cost effective?
  12. How is Z-STOP packaged?
  13. What are Z-STOP Nails?
  14. How should stores merchandise Z-STOP?
  15. Other questions?

What is Z-STOP?

Z-STOP is a product that inhibits the formation of moss, fungus, algae and mildew on roofs. It is a roll of material 2 1/2 inches wide by 50 feet long that fastens to the top of the roof, on both sides of the ridge cap

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How does it work?

When exposed to the atmosphere and rain, Z-STOP forms a surface coating of fungistats. Rain washes minute quantities of these fungistats from the surface of the Z-STOP and down on the roof surface below. It is these fungistats that inhibit the growth of fungus, algae and moss.

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Is Z-STOP toxic?

Only to fungus type organisms (fungus, moss, algae and mildew). Z-STOP is not toxic to anything else - humans, animals, plants and fish are not affected in any way. Z-STOP has been fully approved by the EPA (Environmental Protection Agency).

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How is Z-STOP installed?

Existing moss, fungus, algae, and mildew should be removed first, either by use of one of the chemical treatments made for this purpose or by pressure washing (water blasting). Use of chemicals (see magazine articles for bleach solution) usually involves spraying the chemical on the roof, then brushing or scrubbing to remove the existing build-up of fungus. Almost all chemicals used for killing fungus or moss are at least somewhat toxic to plants, so adjacent pIants should be covered. Also, care should be taken to rinse the chemicals off any metal on the roof: gutters, flashing, and downspouts, as many of these chemicals are corrosive to metal.

Using a pressure washer (available from most rental yards at modest charge) frequently saves work on this step....especially on moss. Fungus and aIgae can take a little work to remove... particularly the "black algae" that is seen in some parts of the country. Spraying the roof with a garden house is hardly ever enough to remove the existing fungus.

After removal of the existing moss or fungus build-up, simply unroll the Z-STOP along and just below, both sides of the ridge cap, nailing it in place approximately every two feet with Z-STOP Nails. The upper edge of the Z-STOP should be butted up against the ridge cap (don't cover up the Z-STOP by tucking it under the edge of the ridge cap; Z-STOP has to be left exposed in order to work). In the case of hip roofs, it is necessary to install the Z-STOP on both sides of all ridge caps, not just the one at the very peak of the roof (this is because rain carries the Z-STOP ingredients to the fungus, and runs straight down the roof from wherever the Z-STOP is applied). Z-STOP can be cut with snips or even with scissors.

To fasten Z-STOP to a concrete, metal or flat tile roof shingle, drill a tap hole in the tile and fasten the Z-STOP with a pan head self tapping sheet metal screw with a neoprene washer under the head of the screw. You can use the washers on the nails we supply with Z-STOP.

Please exercise reasonable caution when doing any kind of work on roofs. Use ladders designed for this purpose. We strongly recommend you follow instructions for chemicals and pressure washer completely. If you are unsure of your skills please consider hiring a professional roofer to clean your roof and install Z-STOP.

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Aren't there chemicals that do the same thing?

No. While there are a number of chemicals that act as fungicides (and they are good to use to remove the existing build-up before Z-STOP is installed), none of them has a long term, residual effect. Another problem with chemicals is that they usually have other toxic effects, particularly on adjacent, planted areas. They can also corrode the existing metal flashing, gutters and downspouts.

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What kind of roofs will Z-STOP work on?

It can be used on all wood, composition, concrete, metal or flat tile roof shingles. However, it is not suited for Spanish Tile roofing products because their shape does not allow rainwater to flow continuously from the ridge cap all the way down the roof.

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Won't the shiny strip of Z-STOP be very noticeable on the roof?

Not really. The shiny finish quickly weathers to a dull, neutral gray.

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Why remove moss or fungus at all?

Moss can severely damage, even destroy, a roof, by breaking down the fibers in the shingles, forcing them apart and allowing leaks to occur. Many roofs must be replaced prematurely due to damage caused by moss that has been neglected.

Fungus, algae and mildew are less damaging to a roof than moss, in terms of actual destruction. However, it looks terrible: the roof on most houses is one of the largest visible surfaces, and when it is covered with fungus, algae or mildew, it detracts from the appearance of the whole house. Another reason is that fungus reduces the ability of the roof to reflect away light and heat, thus making for higher air conditioning bills.

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Which is the problem... moss or algae?

Both. It depends on the area. Some areas have mostly algae, while others have more moss. Z-STOP works on all moss, fungus, algae and mildew.

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What about cost?

Z-STOP normally retails for around $55 per roll. The average roof takes three rolls, so the average cost to the home owner is $165.

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Is that cost effective?

Yes. The average roof costs between $4,000 and $10,000. If the customer has a moss problem, it can reduce the life of the roof by years. Cost of repeated chemical treatment to roofs is expensive too, both for the cost of the chemical (and pressure washer rental) and for the time required to put it on. Also, each time the other treatments are applied, the roof must be walked on which is hard on the roof.

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How is Z-STOP packaged?

Each roll is attractively labeled. There are six rolls to the carton (at three rolls to a roof, on the average, one carton treats two roofs). There are 45 cartons (270 rolls) to a pallet.

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What are Z-STOP Nails?

Z-STOP Nails are short, neoprene washered, annular ring, galvanized roofing nails. They are packaged in the center of each roll of Z-STOP.

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How should stores merchandise Z-STOP?

A prominent display in the same area as flashing, gutters, etc. is good. The garden and nursery section is excellent. Many stores have it in both places. Z-STOP is best displayed stacked pyramid fashion.

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Other questions?

Please contact us.

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Z-STOP Zinc Strip (50 Foot Roll) For Roof Moss Control Is:

  • VERY cost effective (especially compared to a roof repair or new roof)
  • Long Lasting ... 20+ years
  • EASY to install
  • Completely safe for roofing shingles (unless you're fungus, moss, algae or mildew)
  • Safer and works better than roof cleaning with chemical moss control or moss killer
  • Applied on any roofing material made of composition, flat tile, metal, shingles or cedar shakes
  • An ideal product for both the do-it-yourselfer and the professional.