Gardner & Leak Stopper FAQs – Pro Solutions Direct

Gardner & Leak Stopper FAQs

Asphalt / Blacktop Sealing

Can animals or barefooted children be harmed by walking through wet asphalt sealer?

Most Gardner products are water based asphalt products that in general will not cause skin irritation. However, anyone with sensitive skin should avoid contact. If the sealer is still wet, rinse area immediately with water. For dried particles, try a water based citrus cleaner designed for washing skin, as this should remove any excess.

A second non-health issue is tracking wet sealer into the house. Asphalt sealers can stain, even if cleaned up while wet. Anyone who comes in contact with wet sealer should remove their shoes and other clothing that has sealer on it before they come in contact with fabric, wood, paint, tile, or other valuable household surfaces. If the driveway sealer has dried on children's feet or pet paws it will not track, and it will eventually wear off.

Can I seal a blacktop driveway myself, or should I hire a contractor?

Driveway sealing is a great project to take on yourself, but many contractors do an excellent job. When used as directed, both homeowners, maintenance personnel, and contractors will get excellent results with our products. If you hire a contractor, make sure:

  • They use quality products
  • They do not thin the sealer
  • That they prepare the surface properly (including cleaning and degreasing, patching cracks and holes)
  • They apply the sealer at the correct temperature (65° F and rising)
  • Spread it manually to avoid puddling

When doing it yourself, follow the label instructions thoroughly to do the job right. We have some great application instructions available on this site.

Do I need to patch cracks or holes before sealing?

Yes, large holes and cracks will get worse over time. Sealers are not intended to repair them. Gardner offers the best asphalt driveway repair products in the industry. They are 100% tested and proven with all Gardner driveway sealers and provide the longest lasting protection.

How can I tell when it is safe to walk and drive on?

First, wait the appropriate time, then use a gloved hand or cotton shop towel to rub/touch the surface. If black appears on the glove, avoid driving on it. Press into the surface and ensure that the sealer is completely dried all the way through, not just on the surface. For cracks, insert a toothpick into the crack. If it comes out black and wet, it has not fully cured. Driving or walking on wet sealer can ruin the finish and cause tracking onto garage floors and other surfaces you contact.

How do I fill medium to large holes?

Gardner Blacktop Drive Patch is designed to patch large cracks and small holes from ½" to 3”. Follow label directions for detailed instructions. This asphalt and sand mix, trowels to a smooth finish. RePave Pothole Patch is designed for holes larger than 4” up to large potholes. This product can be used year round and after application is ready for traffic immediately.

How do I remove weeds, grass and other plants growing in my driveway cracks?

There are a number of commercial weed killing products designed for killing weeds, but they typically take days and must be completely dry before sealing. A faster approach is to use a screwdriver or other narrow weed puller to dig out the entire plant.

How long should I wait before applying a second coat?

A second coat should be applied after the first coat has cured. Under ideal conditions, typically we recommend waiting 4-12 hours, and until the first coat is fully dry and cured all the way through the film. In optimal conditions, if the driveway is sealed early in the morning and the entire driveway is in full sun and is fully dry, you may apply a second coat the same day. However, many factors, including thick or uneven coats, cooler surface temperatures, high humidity, areas of shade, overcast conditions, and poor air flow, each can slow dry times and require a longer re-coat time.

To improve dry times, do not let any product "pond" or puddle up. Thinner coats that completely cover the surface dry faster, and multiple thin coats perform better than single thicker coats. Curing times can vary. See and follow label directions for more information about your specific product.

How much sealer do I need to buy for my driveway?

Coverage rates will vary by sealer and by the condition of your driveway. A driveway that has not been sealed recently will require more sealer to fill in pores and cracks that have developed. Gardner has developed a coverage calculator to help you decide how much sealer to buy for your driveway. You can access it by finding a product and clicking on the coverage calculator.

Please note that if you get too much coverage, you are applying too thinly; conversely, too little coverage may mean you applied too thick, unless your surface is very rough or very porous.

Always buy more sealer than you need, for a few important reasons

  • First, if you run short and need to stop to get more, the sealer already applied will cure and there will be a visible line where you stopped to get more sealer.
  • Second, the application temperature and other conditions will be different when you re-start, creating another “change” in the appearance of the sealer.
  • Finally, if you stop to buy more, you risk getting product from different batches or different brands than you started with.

How soon after installation can a new asphalt/blacktop driveway be sealed?

We recommend you wait at least 6 months including one full summer season prior to sealing to allow it to fully cure and weather. After 6 months use the water bead test to determine if your driveway is ready to be sealed: spray water across your driveway; if it forms beads, it is not fully cured and not ready to be sealed yet, so you'll have to wait a bit longer.

How soon after sealing can I drive on my blacktop driveway?

Under most conditions you can drive on your driveway 24-48 hours after the last coat is finished. There are a few issues to note that affect dry time:

  1. Areas in full shade will take longer than areas in full sun.
  2. Cooler temperatures below 80° F and higher humidity above 50% can add up to 12 hours to the full cure time.
  3. Driveways with many cracks take longer; the more cracks and the deeper the cracks, the longer it takes to cure.
  4. Thicker coats slow dry time. We always recommend two thin coats for best results.

I have a concrete sidewalk and brick pavers along my driveway. Can I seal over these areas? If not, how do I avoid getting asphalt sealer on them?

Gardner driveway sealers are meant only for blacktop/asphalt surfaces, not for concrete or brick. To minimize the chance of getting asphalt sealer on these areas, you can first mask with tape and plastic sheeting or a drop cloth along the affected edges. Another option is to carefully “cut in”—or coat a six-inch wide strip along the edge of your driveway using a smaller brush to coat the driveway edges.

As a side note, be careful not to place lids, applicators, wiping clothes, or pails of sealer on a concrete or brick area and avoid spills. Also be aware that your wet shoes can track asphalt sealer onto garage floors and sidewalks, so they should be removed before walking on these areas.

I have multiple batch codes, how do I ensure all product is consistent and provides a uniform result?

It is always best to mix the buckets to ensure proper sheen from one pail to the next, just as you would with house paint. This can be done by pouring half of one pail into half of another pail.

I have spilled sealer on an area that I shouldn't have. What is the best way to clean it up?

All of our driveway sealers will wash off with soap and water when the sealer is still wet. However, if it has dried there are a couple of ways to clean it up. There are a number of high performance citrus-based cleaners available at automotive stores and many home center and hardware stores that work to dissolve dried coatings.

I purchased some sealer in the fall and want to store it in my garage to use in spring. Any concerns?

Gardner sealers are water based, so they cannot be stored where they will freeze. If the product freezes, it is ruined, and will be very difficult to remix. If the product does freeze, do not use it. If the product is protected from freezing and stored in a heated room at 50 degrees or higher, you should be fine. Driveway Sealer should be used within 1 year of purchase.

I've tried using a paint stir stick, but is there an easier way to mix 5 gallon pails?

First, we realize that traditionally stirring has been the most difficult part of the asphalt driveway sealing project. That's why Gardner has created patented no-stir driveway sealers to make your job much easier.

However, if you buy one of our E-Z stir products, there are some techniques that make stirring even faster and easier.

  • First, before opening the pails make sure the lid is securely fastened. Then flip over the pail and store on its lid for at least 24 hours prior to using the product. Flip over and shake slightly before opening the lid. The flip back over and stir. Mixing should be much easier.
  • Second, you can use an empty pail to pour two or more pails together back and forth (a process called “boxing.”) This is particularly useful to achieve a uniform finish if you are not sure whether all of your pails came from the same original batch.
  • A third option is to buy a mixing blade attachment for your power drill, available at many hardware stores and home centers.

If I use a squeegee on my driveway, how do I do the edges? A squeegee seems too big and clunky for trimming around the edges.

Rubber squeegees are your best applicator, but avoid plastic ones—they can skip and fail to give you a precise edge. But for even more precise control, try a broom or brush designed specifically for driveways. Also, you can mask off areas that you want to avoid coating with sealer by using plastic sheeting or drop cloths (as you would when painting). However, make sure you tape down the edges—failing to do so will cause sealer to wick up under the sheeting or drop cloth.

Is an asphalt sealer the same thing as a blacktop sealer? What about tar?

A blacktop driveway and an asphalt driveway are the same thing—asphalt is the more “technical” term. Asphalt is naturally black in color, so you'll hear sealers referred interchangeably as “blacktop sealers” or “asphalt sealers.” However, the “tar” terminology is not applicable to Gardner brands. It refers to an ingredient called Coal Tar. Gardner products have been upgraded from older coal tar-based technologies into better performing asphalt based formulations.

Should the driveway surface be hot or cold when applying sealer? Wet or dry?

A hot, dry driveway above 95° F will dry to fast; the result can be a very uneven finish. We recommend cleaning the surface first using a driveway cleaner, which also serves to cool off the surface. Make sure there is no puddled water on the driveway before sealing.

If the surface is too cold means the sealer will not set and cure properly. For best results we always recommend application at 65° F or higher for several hours before application, to ensure the surface is warm enough to allow a proper protective film.

Shady areas, high humidity or cloudy conditions can slow the cure time of the sealer, so additional dry time between coats may be needed.

What is the best temperature and weather to seal a driveway?

The best sealing weather is in the morning hours with temps between 75° F to 90° F, with sunny clear skies and no rain. However, sealers can still be applied when the driveway surface temperature and air temperature are at least 65° F and rising. The temperature should not drop below 60° F during the curing process (24 hours).

Don't wait until fall to seal the driveway from ice and snow, in fact it's important to seal it against rain and UV rays that can damage asphalt and create cracking and crumbling. So sealing your driveway during any month when temperatures and weather are appropriate is beneficial to protecting your driveway surface.

What tools will I need for my driveway sealing project?

CLEANING: Clean with blower or broom. Then clean driveway with a driveway cleaner with your garden hose to clean and prepare the surface.

APPLY SEALER with a rubber squeegee and/or bristled broom. Plastic squeegees and paint rollers are not recommended.

What's the best way to fix a small crack

Gardner® Blacktop Crack & Joint Filler is our best, highest flexibility crack filler, ideal for cracks and joints up to 1” wide. This product also works great for expansion joints. Dries fast.

What's the best way to fix larger areas of cracks?

For larger areas of cracks ½" – ¾", fill them with Gardner® Elastomeric Crack Filler. This product comes in a 1 gallon jug with an E-Z Pour spout. Applies quickly and easily.

Why do I need 2 thin coats? Won't one thicker coat work?

Applying two coats of any sealer will dry and create a better finish much better than one thick coat. These sealers are water based, and they cure and form a film primarily during the evaporation of water from the coating. A thin coat will evaporate much faster and create a single uniform layer. A second thin coat will fill in areas not filled by the first coat and create a deeper, richer, more uniform coat. Single thick coats cure less evenly, have a tendency to puddle, and are prone to tracking.

Why do I need to stir driveway sealers?

The good news is that now you don't have to stir if you use Gardner's premium no-stir gel formulas. These patented formulas keep all the particles in suspension, so you get an even finish without stirring. However, it is recommended that all driveway sealer buckets are turned upside-down before opening the container. This will ensure proper dispersion for gel sealers, and it makes all other driveway sealers much easier to mix in.

If you buy driveway sealers that still require stirring, the main reason for stirring is to mix together particles that settle naturally during shipping and storage. Failing to stir these sealers can create very uneven color and finishes, gritty areas and slick areas, areas that have little protection, uneven wear, etc.

Caulks & Sealants

Paint cracking around caulk joints

The paint most prone to cracking over newly applied caulk is a cheap interior flat Latex. If you use this paint, there is no room for error, and the caulk must be allowed to fully dry (overnight) before painting. Premium paints do not have this same problem, and seem to have less cracking issues over newly applied dry caulk.

Why don't caulks "stick" sometimes?

Caulks don't stick to dust, chalk, dirt and other contaminants. Also remove any loose or damaged substrates. Washing an area and letting it dry before caulking can really improve adhesion.

At what temperatures should caulks be applied?

The best application temperature range for caulks is 60°F to 85°F.

Should I prime before applying sealant?

Priming is generally not necessary before sealing if surface is sound.

What does "elastomeric" mean?

The term elastomeric refers to the ability of a material to stretch and then return to its original shape, i.e., it has "memory." Elastomeric caulks are normally the better choice and an excellent choice with any kind of paint.

How wide/thick should I apply caulk?

A line of caulk (called a "bead") should be no thinner than ¼." Thinner beads shrink while drying, creating too thin a seal to tool or seal properly.

When should you use a Backer Rod?

When filling a crack, seam or joint that has a gap wider and deeper than ¼", a foam backer rod is first placed in the gap to partially fill it. Backer rods improve adhesion and flexibility of the seal by creating an hourglass-shaped seal with the caulk.

Which caulk is best for caulking around sinks and tubs?

Tub & Tile Caulk is recommended in areas where there is high humidity and intermittent water contact such as kitchens and bathrooms. Tub & Tile Caulk contains added mildewcide to give consumers extra mold & mildew fighting protection.

What is mildewcide?

Mildewcide is an additive in caulks and paints that deters the growth of fungus, mold and mildew on the dried caulk film.

How can I ensure that mildew will not grow on my caulk?

Mildew can grow anywhere there is darkness, dampness and a food source. Clean the area you are going to caulk with a bleach and water solution.

Pro Painter Answers About Caulks & Sealants

Bead Size: How thick do I apply it?

The best rule of thumb is to use your finger to wipe down a caulk bead. Do NOT use a rag as it will wipe away too much caulk and lead to cracking. You don't need to use more caulk, just don't wipe away the product you have already used! Remember to moisten your finger before tooling the caulk. The moisture allows for a smoother finish.

Help with Drying Time

Our specially formulated caulks offer standard, faster, and slower dry time options. We have a caulk that meets your job needs ranging from the cool Northeast, to the humid Southeast, to the dry Southwest, and the moist Northwest. We provide solutions to keep you painting through all climates and conditions.

Know when to stop!

If it looks good, walk away! Trying to create the perfect bead is a good way to mess up an otherwise acceptable job.

Preventing after flow

Remember to immediately release the trigger on the caulking gun each time you complete a bead. This helps to reduce the amount of caulk that weeps from the tip.

Sealing Crown Molding

Decorative molding demands the best caulks that have great adhesion and flexibility. Crown molding expands and contracts due to the temperature differences in rooms. Temperatures can differ up to 15 degrees from floor to ceiling, and crown molding must endure the greatest temperature movement. Use only high quality elastomeric caulks for this application.

Cool Roof Coatings

Can cool roof coatings be thinned, and if so, with what type of thinner?

While you can use water to clean brushes, rollers, and other items used in application, do not thin these products unless label instructions expressly direct you to do so. Our cool roof coatings are ready to use; thinning them can lead to a number of unintended results, including: reduced service life; inconsistent appearance; creating a film that contains gaps or voids; contribute to blistering and peeling; poor hiding and coverage; increased chance of mold growth; and more. Thinning with mineral spirits or other flow enhancing chemicals can ruin a water based cool roof coating, and may violate government Volatile Organic Compound (VOC) regulations.

What effect does ponding water have on cool roof coatings?

Water based coatings do not perform well on roofs that pond water (i.e., areas of a roof that have slow-draining puddles on them). Dirt can accumulate in depressions and inhibit the reflectance of the coating. If a water based coating is under water for a prolonged period of time, the water may work its way under the coating causing it to peel, or erode the coating and create gaps in the film where water can intrude. Positive drainage is needed to flush away surface dirt and retain the reflective properties of the coating. Keep drains clean and re-grade the roof if needed so that ponding does not occur.

Which type of roofing can I use this on? Asphalt shingles? Tar paper? Plywood?

Each product label indicates the surfaces it should be used on, for which applications, and how to use it. If in doubt, check with the manufacturer of the roofing material to ensure that any coating used does not void any warranty on the roof.

Will a roof coating stop the leaks and waterproof the roof?

Complete waterproofing is a system approach, that includes the construction of the roof, the roofing materials and how they are assembled and installed, and coating systems. Over time, with settling and wear on roofing materials, even the best roofs can develop leaks and ponding areas. For best results, ensure there is positive drainage and drains are clean and clear, and repair all leaks and cracks with a roofing cement and reinforcing fabric prior to using a cool roof coating.

Will Cool Roof coatings significantly increase my winter heating costs?

Cool roofs deflect some desired heat gain during the winter. In general, though, cool roofs result in net energy savings, especially in areas where electricity prices are high. Using Cool Roofs to Reduce Heat Islands. (2016, August 12). Retrieved from

Can I coat a rubber roof with a cool roof coating?

Some rubber roofs can be coated with popular acrylic latex elastomeric coatings, some not. Proper surface preparation is a key to proper adhesion, including removing all chalking, dust and dirt and killing and removing mildew by pressure washing. New formulas designed for rubber roofs may be available; if possible, check with the rubber roofing material manufacturer for suggestions. Finally, be sure to test any coating, especially in "trouble areas" such as shady areas, perennially wet areas, or areas where previous coatings have failed or eroded more quickly.

Roof Coatings & Cements

Can Gardner products be thinned and if so, with what type of thinner?

Gardner products should not be thinned unless labels expressly direct so. Thinning a product designed as ready-to-use can impact performance, and thinning certain products may violate government Volatile Organic Compound (VOC) regulations.

Can I apply Gardner coatings or cements if it will rain soon?

Yes. The products designed for wet weather application include:

Can I use this on rubber roofing?

Some rubber roofing materials require special cements and coatings manufactured for use on these materials alone. Check with the manufacturer if you are not sure.

Can new built-up roofs be coated with aluminum coatings sooner than the recommended 90 to 180 days weathering period?

If an aluminum surface roof coating must be applied sooner to a new built-up roof, a water based emulsion coating should be used instead of a solvent-based asphalt coating. An emulsion coating will provide a firm base on which to apply the aluminum coating 5 to 10 days after the emulsion has cured.

How do I clean up a spilled Gardner product?

Consult SDS data sheets for the specific products.

How soon can I coat a newly installed built-up roof with an aluminum roof coating?

New asphalt built-up roof (BUR) surfaces should weather a minimum of 90 to 180 days prior to coating with Gardner aluminum roof coatings.

What effect does ponded water have on aluminum roof coatings?

Aluminum coatings do not perform well on roofs that pond water. Dirt can accumulate in depressions and inhibit the reflectance of the coating. If an aluminum coating is under water for a prolonged period of time, the water may work its way under the coating causing it to peel. Positive drainage is needed to flush away surface dirt and retain the reflective properties of the aluminum coating.

What factors can reduce the reflectivity and long-term durability of aluminum coatings?

Before Application: Poor Drainage, poor surface preparation, or improper mixing.

During Application: Under-applying, over-applying, or misapplying (cross-directions)

After Application: Traffic, climate and geography, or surface contamination

What is the dry or cure time for Gardner products?

The dry or cure time for Gardner products depends on the specific product used. Check label instructions for specific cure times. Dry time can be affected by air and surface temperature, wind, humidity, porosity of the substrate, and the type and amount of product used, among other factors.

What is the life expectancy of Gardner’s aluminum roof coatings?

Normally, aluminum roof coatings have a service life of between 3 to 7 years, depending on the surface coated and other factors.

What should I use to mix aluminum coatings?

All containers should be stored upside down at least one day before application. Before applying, five-gallon containers of aluminum products should be mixed well using a 5-gallon stir stick or a drill with a double-bladed paddle mixer until a consistent silver color is achieved. One gallon cans can be tipped and shaken manually (do not use mechanical paint shakers) before opening, then stirred with a 1-gallon stir stick until a uniform silvery color is achieved.

Which type of roofing can I use this on? Asphalt shingles? Tar paper? Plywood?

Each product label indicates the surfaces it should be used on, for which applications, and how to use it. If in doubt, check with the manufacturer of the roofing material to ensure that any cement or coating used does not void any warranty on the roof.

Why are "Silver Shield" and "Silver Seal" not “silver” in the can– it’s gray or brown in color?

Aluminum coatings in the can are typically a bronze color. Thorough stirring will turn the product silver, but it may still have a slight bronze tone while applying. However, as part of the curing process the product “transforms” to create a bright silver film. So even while you’re applying the product, some areas will have turned bright silver while the most recently applied areas are in different stages of turning from silvery bronze to bright silver.

Why are Silver Seal and Silver Shield not a uniform color when dry?

Aluminum coatings should be a uniform, bright silver when dry. Several issues can contribute to creating a non-uniform appearance, including overlapping, improper mixing. rain, dew or snow.

Why is there a greasy residue coming off the roof after the application of aluminum roof coatings?

As the product cures, solvents evaporate and are naturally washed off the roof with rain. During dry spells, if the solvents have not been washed away, there may be a residue left on the roof surface.

Why should I use an aluminum coating to coat my roof?

Aluminum coatings can form an invaluable part of a smooth surface built-up roof (BUR), smooth or mineral surface modified roofs (SBS) or torch-down (APP) roofing systems.

Aluminum coatings form a highly reflective surface that can lower roof surface temperatures as much as 40F, which can equate in lower internal temperatures.

Aluminum coatings also protect the underlying membrane (BUR, SBS, or APP) from UV degradation, thereby helping prolong its life.

In brief, Aluminum coatings:

  • Extend the life of the roof system.
  • Reduce roof surface temperatures.
  • Reduce thermal shock and stress to the roof.
  • Make leaks easier to identify.
  • Help the environment by reflecting heat and reducing temperature.
  • Provide fire protection (See UL Class A Fire Ratings)

Will a roof coating stop the leaks and waterproof the roof?

For best results, all leaks and cracks should be repaired with a roofing cement and reinforcing fabric prior to using seal coating.

Wall Covering & Wall Repair

Can I paint over old wallpaper?

Yes. However, like installing wallpaper over old wallpaper, it is always best to remove the old wallpaper prior to painting.

How do I get wallpaper to hang straight? I can never get the pattern to match up.

Make sure the first strip hung is hung level using a plumb line. This should solve your problem.

I removed some wallcovering, and it tore the paper on the wallboard. Is there anything I can do to fix it?

Remove the loose paper. If the damaged area is small, it can be repaired with Lightweight Spackling Paste. If it is a large area, float the area with a drywall skim coat.

I'm worried about using scrapers and scoring tools to remove old wallcoverings. Wont they create marks on the wall that will “show” through the new wallpaper?

Yes. To minimize the damage, the key is to soak the old wallpaper with liquid wallpaper remover several times before scraping.

Is it okay to use a steamer to remove wallcovering?

Yes. Most of the time applying multiple applications of wallpaper remover solution will work just as well.

Is sizing necessary? What about priming?

Unpainted drywall, or drywall with old, flat “builder paint,” is too porous; sizing is needed to close up or even off the porosity to get consistent adhesion of the wallcovering paste. Shur-Stik® Hide & Hang, a combined primer & sizing, is better rather just a plain size for creating a uniform surface with excellent tack and repositionability.

Should I use a clay-based or a clear adhesive?

Wallcoverings that are difficult to hang and curl at the edges often require the extra tack of a clay-based adhesive. Clear adhesives have sufficient tack to hang all other types of wallcovering. Both types need to be cleaned off all surfaces with clean water while still wet.