Pressure treated wood can last up to 30 years without rotting, and that’s because the treatment protects the wood from termites that contribute to decay. This product offers confidence in outdoor building projects due to its enhanced durability. When it comes to joining pressure treated wood, you can go for various screw types. But can you use zinc coated screws in pressure treated wood?
Yes, you can since the zinc coating will prevent the screws from rusting over time. However, not all zinc coated screws will do the job correctly.
For instance, electro galvanized screws always have a first corrosion rate as soon as they get exposed to the elements. On the other hand, mechanically galvanized screws will offer more corrosion resistance.
It would help if you didn’t use these screws on your pressure treated wood. For example, if you come from areas with high salt content or moisture in the air.
So what’s more about the pressure treated woods and the zinc coated screws?
Let’s find out…
Table of Contents
Are Zinc Coated Screws Rust Proof?
Most zinc coated screws are rust proof since they have undergone galvanization, thus protecting them from the rust forming elements.
For these reasons, you can use these screws on all your outdoor projects. The zinc coating acts as the sacrificial anode that decays before the metal inside.
Even though electro galvanized screws will still offer protection from the weather, they have a bright and shiny appearance.
Thus, I don’t recommend them for outdoor use since they’ll leave black streaks around the nail. For this reason, mechanically galvanized screws are the best option for pressure treated woods.
Even so, you can go for other screws like stainless steel.
Note: Although zinc coated screws are rust proof, they always break down and oxidize over time.
It only becomes an advantage when you’re working on a short lived project.
Do Screws Rust?
Yes, they’ll rust if exposed to the rusting elements. The best remedy is by dipping them in a rust resistant coating like zinc.
However, as soon as the coating chips or flakes away, rust will form and eventually undermine the screw’s strength.
What Type of Screws and Nails Must Be Used in Pressure Treated Lumber?
I recommend using hot dipped galvanized nails or screws. Remember that they should have a protective coating designed for use with pressure treated wood.
The best example is the outlaw fasteners.
Tip: Never use the standard bright finished nails, sheetrock screws, or ones with no coating on them.
It’s also good to determine the type of pressure subjected to the wood during treatment before considering suitable nails or screws for use.
For instance, screws and nails galvanized with zinc are best for use with copper treated wood.
Besides, they must meet the ASTM A153 standard for any zinc coating quality and the G-185 standard for the coating quantity.
Here are other types of screws for use on your pressure treated lumber:
- Stainless Fasteners
You can get corrosion resistant stainless steel bolts, nails, and screws in grades 304 and 305.
Such types are ideal for use in most areas of copper treated woods. Grade 316 are most suitable for use in the coastal regions.
However, such screws and nails are slightly more expensive than the galvanized ones. Again, you cannot safely use them with galvanized structural connectors since they may cause adverse chemical reactions.
- Polymer Protected
Most of these nails, bolts, and screws have zinc plating covered with a non reactive organic polymer coating.
The primary need for the coating is to protect copper treated wood from corrosion. It also keeps dissolved copper and water from reaching and racing with the steel and zinc.
What Are the Best Deck Screws for Pressure Treated Wood?
I suggest using G-185 galvanized or polymer coated steel screws.
Such screws should be corrosion resistant. They should also have a coarse thread to offer an increased holding capacity.
Below are some of the common aspects to consider while choosing the best pressure deck screws for pressure treated wood.
- Drive Type: It can be either Philip square or Torx drive.
- Screw coating: Go for a stainless steel finish or ceramic coating. You can also consider other superior coatings.
Note: Galvanized screws are suitable for pressure treated decking. On the other hand, stainless steel screws are best for Redwood or Western Red Cedar Decks since they’ll help prevent staining around the screw heads.
- Head type: Choose from the flat, trim, cap, round, among other head types.
- Screw material: Even though you can choose screws made from different materials, stainless steel is ideal for decking.
- Screw thread and tip: It should have serrated or coarse threads for a long lasting grip. The tip should also be easy to work with.
With the above features to consider, I suggest using:
- Power Pro 48611 Premium Outdoor Wood and Deck Screws
- Deck Plus 48422 Tan Deck Screws.
- Galvanized Dual Torx Deck Screw #8 x 1-1/4”
- The Hillman Group 47694 Galvanized Deck Screw.
- #10 x 2-1/2” Stainless Steel Deck Screws, Type 17 Wood Cutting Point, Star Drive T25, 18-8 (304) Grade Stainless Steel,
Can You Use Regular Screws In Pressure Treated Wood?
I don’t recommend doing this since most electro-galvanized screws (clear zinc coated) are not ideal for exterior surfaces.
Such screws always corrode quickly as soon as they get in contact with the elements. For this reason, always consider the mechanically galvanized screws for all your outdoor applications.
Note: Regular steel can quickly rust, thus losing strength.
The copper in the pressure treated wood can also react with the steel to cause corrosion and loss of shear strength.
How Long Do Zinc Coated Screws Last?
Most zinc coated screws have a fragile layer of zinc. Therefore, they are prone to scratches or easy wear, resulting in rust.
However, due to the introduction of the steel screws with a zinc-chromate coating and a clear rust resistant material, most screws can now last longer.
For instance, they can stay for at least 500 hours in a moisture chamber with a 5% salt spray solution.
The standard zinc plated screws only take 100 hours in the same conditions before seeing the first red rust.
Note: Hot-dip galvanized zinc coated screws can last for more than five years. However, the duration will depend on the environmental conditions.
How Long Will Electro Galvanized Nails Last in Treated Lumber?
Such nails have a lifespan of up to 5 to 10 years, depending on the environmental conditions.
The nails are suitable for lower quality galvanization applications since they have a skinny coating of about 0.36 mils.
For this reason, electro galvanized nails are ideal for most indoor applications on treated lumber.
Are Zinc Plated Screws OK for Outdoor Use?
Zinc plated screws have good grip and durability, but they are not ideal for outdoor use. Therefore, I suggest brass plated and copper plated screws for outdoor use.
However, zinc plated screws are not as strong as steel.
Note: The zinc coated screws are not ideal for use in marine environments and underwater.
What Is The Difference Between Galvanized and Zinc Plated?
It’s good to note that both galvanizing and plating are processes of zinc plating. But here are the significant differences:
- It has a thickness of 0.2 mils.
- Ideal for consumer, industrial, and commercial products for surface finishing.
- Relatively low cost.
- They have an attractive appearance as a protective nature.
- It can be coated with post plate chromate treatments to improve corrosion resistance.
- Hot dip galvanizing is the all true one.
- It can last up to 20 years.
- It offers over five times protection.
- The galvanized product develops zinc oxide (a white protective coating) to add protective properties.
- It can be up to 1.0 mil thick.
Will Zinc Screws Rust In Salt Water?
Of course, zinc screws will not last in saltwater. It doesn’t even matter whether it’s salt or freshwater.
If you insist on using zinc screws in saltwater, go for the ones with thick zinc anodes since they are the best choice to act as sacrificial anodes.
The reason is that the zinc alloy is less resistant to the salt water’s electrolytes. As a result, it plays a significant role in stopping oxidation to the rest of the metal part as the zinc dissolves.
It’s wise to remember that zinc coated screws are not rust-proofs. Instead, they resist rust but not for a prolonged period.
What Kind of Screws Won’t Rust?
I recommend stainless steel screws. These screws are entirely rust resistant, not just on the surface like other standard ones.
With the rust resistant material, stainless steel screws are strong, durable, and don’t wear off over time.
Why Can’t You Use Coated Nails in Treated Lumber?
First, you have to know that treated lumber has some chemical preservatives. These compositions will prevent you from using coated nails since they adversely react with many metal products.
For instance, most treated lumbers have copper based preservatives. Thus, they may cause the vinyl coated steel nails or other metal coated ones to rust prematurely.
So, how can you become a professional in choosing the best nails for your treated lumber?
Let’s find out below…
Acceptable Fasteners for Preservative Treated Lumber
Vinyl coated sinkers will rust when in contact with pressure treated wood. However, there are other options of corrosion resistant fasteners for use on pressure treated lumber products.
For example, stainless steel and hot dipped galvanized fasteners are ideal for load bearing or framing applications.
Alternatively, you can choose to use copper or bronze fasteners. But I don’t recommend them for construction and residential projects.
Stainless steel stands out since it’s more resistant to corrosion.
Note: Electroplated galvanized fasteners are less resistant to corrosion since they have a thin protective layer.
Can You Use Liquid Nails On Pressure Treated Wood?
Yes, you can. Liquid nail is a low solvent, multipurpose, high strength construction adhesive. The product is ideal for interior and exterior use on pressure treated wood.
It’s also weatherproof grade adhesive that offers easy cold weather gunning ability.
Liquid nails can easily penetrate wet, frozen, and treated lumber offering the best adhesion properties.
The Application Tips
Step 1: Surface preparation
Before using this product, ensure you thoroughly clean and dry your pressure treated wood. Then, for the case of paneling, apply the conditioning according to the manufacturer’s instructions.
Pro Tip: Remember to research all the installation instructions. Also, you must carefully read the safety, environmental, and health information.
Step 2: Apply
Use a caulk gun for this step. Then cut the nozzle and puncture the inner seal using a thin wire or nail.
Suppose you are working on wall cabinets or countertops. Consider applying at least ¼” bead to all the contact areas.
Step 3: Fastening
After applying the liquid nail, press the treated woods into place, then use mechanical fasteners to hold them together permanently.
In furring strips and studs, use at least a ¼” zigzag bead to each of them. Afterward, press them into place using specified nails both from the bottom and topside.
On drywall, apply approximately ¼” zigzag bead on each stud. After this, gently press the drywall into place.
Is Liquid Nails Better Than Wood Glue?
Let’s take a brief check on each product to figure out the main differences.
- Liquid nail is the brand name for construction adhesive.
- It provides incredible bonding strength, especially for nonporous surfaces such as varnished or painted wood.
- You must brace or clamp the adhered surface for at least 24 hours.
- It takes a whole week to dry to maximum strength.
- They emit fumes when wet thus, it’s necessary to have ventilation.
- The solvents are toxic and flammable before drying but safe afterward.
- Some varieties don’t emit fumes.
- They feature both latex and solvent based versions.
- You can easily remove it from your hands by rubbing mineral oil or petroleum jelly on the affected area.
- It’s an incredibly versatile adhesive.
- The product settles in only 15 minutes.
- You need up to 24hours before applying any stress on the glued area.
- It’s safe since it does not emit fumes.
- There are some categories rated for food based usage, e.g., cutting boards.
- It’s latex based. Thus you can wash it off with soap and water.
- It’s ideal for bonding wood pieces.
Can You Use Stainless Steel Screws In Pressure Treated Wood?
Yes, you can. As stated before, stainless steel screws are the best screws for use in pressure treated woods.
They are also suitable for use in areas exposed to harsh outdoor conditions.
Pressure treated woods are very sensitive woods. Therefore, it’s good to use reputable stainless steel fasteners for such woods.
Note: Most pressure treated woods have highly corrosive compositions such as copper azole and alkaline copper quaternary.
Therefore, consider using hot dip galvanized steel, stainless steel fasteners, and industrial consumables.
How Can You Tell If a Screw Is Zinc Plated?
You can identify a zinc plated screw from its dull gray color with a matte finish. However, you’ll also realize that some will look drippy because of dipping in melted zinc.
Note: Galvanized fasteners have a hardy dull industrial look.
Which Is Better Zinc or Stainless Steel?
Stainless steel is a little bit more expensive than zinc plated screws due to the chromium content. Even so, stainless steel is tough, more robust, and resists corrosion.
Zinc is a heavy element. Therefore, its alloys have better corrosion resistance, dimensional strength, impact strength, and stability.
It also has a lower casting temperature. Thus, it offers a longer die life, which contributes to the reduced production cost.
Stainless steel has a shiner and a more refined look. It’s also fully rust resistant compared to galvanized zinc which only has a thin layer of coating.
The screws also have an incredibly high tensile strength between 100,000 and 150,000 tensile pounds per square inch (PSI).
Tip: Galvanized screws are more attractive due to their low price.
How Can You Tell if a Nail Is Galvanized?
Here, we will look at how to check if a nail is galvanized. However, I don’t recommend using them on treated wood, cedar lumber, or redwood.
The reason is that the nails can easily rust when paired with such materials.
Here are the steps necessary in determining galvanized nails:
Examine the color of the nail. Such screws always have a silvery gray color due to the zinc coating.
Check the nail’s texture by rubbing your fingertip across the shaft. Galvanized nails have a rough finish.
The coating on such nails always looks like it’s running because of being dipped in melted zinc.
Finally, consider checking the size of the nail. Galvanized nails have a large nailhead and a short to moderate length.
Note: Due to the large head size, they will not leave a headless finish.
Can You Use Galvanized Nails In Non Treated Wood?
I don’t recommend using galvanized nails on naturally weather or rot resistant woods like cedar or redwood.
The reason is that zinc will react with the chemicals in the wood, which will result in the formation of black streaks and stains.
Note: The hot dipped galvanized nails are the best quality available. These nails offer a minimum of up to 1.7 mils of zinc coating thickness.
You can identify such nails by checking if they are ACQ approved.
Don’t even think of using the lowest quality galvanized nails for the non treated woods since they’ll quickly rust and streak the surface.
Pro Tip: Stainless steel nails will offer the durability and quality finish on such wood types.
How Long Will Non Galvanized Nails Last In Treated Lumber?
Unlike galvanized nails which can last for up to 30 years, the non galvanized nails will barely last two years.
Also, instead of using aluminum for flashing, go for copper.
What Is Pressure Treated Wood Preservative Treatment and How Does it Work?
Pressure treating wood is when you introduce a preservative formulation into the wood under a certain pressure.
Mostly, professionals go for AWPA treatment since it’s safe and proven to offer protection on outdoor wood from termite attack and decay.
Generally, using this method increases the durability of the wood, thus helping to preserve the forest.
Can I Use Treated Wood Inside?
Yes, you can, especially for sill plates of homes. In addition, the fire-retardant treatments in these woods offer additional protection from smoke and fire development.
Many treated wood products are also ideal for interior use since they don’t emit fumes.
Note: Don’t use treated woods on countertops or any other area where it might get in contact with food.
Are all Screws Made of Zinc or Steel?
You’ll realize that the most durable screws are steel (an alloy of iron and carbon).
There are other materials added to it that enhance its corrosive resistance and strength.
Such materials include zinc which is an expensive coating for enhancing corrosion resistance.
Most zinc coated screws will last as long as the zinc coating is still intact. Therefore, go for thick coated screws instead of the thin coated ones for enhanced durability.
Pro Tip: If you see an HDG label on your box of screws, it simply means that they have not undergone galvanization.
How Do Galvanized Screws React With Aluminum?
Galvanized screws have a zinc coating that enhances corrosion resistance between the aluminum surface and the screws.
Note: If you use these products in moist conditions, the zinc coating and the aluminum surface connection will become conductors.
Therefore, ensure you use a barrier or an insulator to avoid shocks.
Are Screws Better than Nails?
These two products are all good depending on the purpose and where you’re going to use them. However, I recommend using screws since they have a better grip and are available in different types.
Will Zinc Screws Weaken My Pressure Treated Wood?
Yes, they can but under certain circumstances. For instance, the degree of impact will depend on your wood’s thickness, angle of joint, and how close you place the screws to each other.
For this reason, you need to be careful while screwing your pressure treated wood. You can consider drilling pilot holes or using liquid nails before fastening the pieces together.
When Should You Use Galvanized Screws and Other Outdoor Screws?
By now, you know that galvanized screws and nails have undergone galvanization. Thus, they have a protective barrier for rust and corrosion resistance.
You can use these nails for most outdoor projects, especially in damp areas.
However, don’t go electroplated galvanized nails or screws on certain redwoods and treated lumbers.
An alternative to the galvanized screws is stainless screws, which are the strongest and best at resisting rust and corrosion.
How Much Weight Does Treatment Add to The Weight of Wood?
Most of the added weight indeed results from water used in carrying the preservative components.
Therefore, a freshly treated wood may contain at least 2 – 4 gallons of water per cubic foot (16 – 32 lbs).
But as the wood dries, the water will evaporate only to leave the preservative, thus reducing the overall weight.
How Often Should I Apply a Finish To Treated Wood?
I recommend applying the finish at least annually. But ensure you carefully follow the manufacturer’s instructions.
Tip: Ecolife treated wood comes with a surface water repellency, thus eliminating the need for applying the brush on water repellent after the deck’s installation for about three years.
Can I Dispose of Unused Treated Wood By Burning?
I don’t recommend doing this since such woods always have chemical components of the preservatives.
What if you accidentally burn them? In such a case, the chemical preservatives will release as ash and in particulates as smoke.
Note: Most of these components might be harmful to the environment. Therefore, I recommend proper disposal.
Up to this point of the article, you have seen the primary role of zinc on screws and nails. One of them included preventing rust. However, it’s good to note that zinc can also rust. The good thing is that the rate of rusting will determine when the underlying metal will begin to rust. So, the remaining question is…
Can You Use Zinc Coated Screws In Pressure Treated Wood?
Yes, you can use them, but not all types will give the best outcome. For instance, thin zinc coated nails or screws will rust quickly. The reason is that the zinc coating that acts as the sacrificial anode will corrode soon, thus leaving the coated metal vulnerable to the rusting elements.
Therefore, I recommend going for mechanically galvanized screws or nails for your pressure treated woods.
With these few points, I want to thank you for taking your time on this article. Suppose you have any question, observation, or additional information related to this topic. Then, would you please leave it in the comment section below?