What is the Janka Hardness Test?


    Wondering what the best type of hardwood is for your indoor / outdoor floor, or deck?  First you should consider where the product is going.  If it’s going into a kids playroom or room that is often used you’ll want hardwood that is in actually hard.  To calculate the hardness of a piece of a hardwood, the Janka hardness test is used.  This industry standard test’s purpose is to measure the resistance of wood to denting and extensive wear.  It works by measuring the force required to embed a .444 inch steel ball into the wood to half the ball’s diameter.  How much force the ball needs to be embedded into your hardwood will show you if your hardwood is easily dented.

The hardness of the wood also varies on the direction of the wood grain.  Testing on the surface of a plank perpendicular to the grain is known as side hardness.  Testing on the cut surface of a stump is known as end hardness.  The most common reason for testing is to determine whether the species of hardwood you have is a suitable use of flooring for your home.


Above is the list showing the hardness of various hardwoods.  If you’re redoing your hardwood floors or renovating a deck remember to plan accordingly.  If you have small children that enjoy dropping anything and everything they get their hands on then you’re going to want a harder type of flooring.  The softer the wood, the more it will wear down while the harder the wood the longer it takes to wear down.


        As you might expect, Ipe is exceptionally strong. It outranks Teak, Oak, and many other hardwoods. It’s also 8 times harder than Redwood, a fact that surprises many except those who own a deck or floor made of Ipe.

Get your free Ipe decking quote directly from the mill. Contact IpeDepot.com today.

The Science Behind the Expansion & Contraction of Wood

Why Wood Moves

Like many building materials, wood expands and shrinks. This is due to how much moisture is in the air.  If there’s high humidity the cells within the wood will expand.  If there is low humidity, the cells will shrink. Thankfully there is a way of predicting how much the wood will shrink or expand.  The equilibrium moisture content (EMC) is basically the length of time it takes for your wood to accommodate to its new environment.   It can tell you whether your wood is going to expand or shrink.  The EMC helps us understand the response wood has to relative humidity (RH).  For example a change in Moisture content (MC) will cause a 12 inch wide maple board to expand or contact by at least ¼ inch.  The graph below gives examples of MC versus RH.


Wood, not only moves, because of its environment but because of many other factors.  Here are six distinct factors as to why wood moves.

  1. Width of Material – The wider the board, the more the movement.
  2. Grain Orientation- Flat and quarter-sawn lumber can make a big difference in telling how much your wood will expand or shrink.  Quarter-sawn shrinks and expands roughly half as much as flat sawn.  Flat sawn shrinks and swells less in thickness while quarter-sawn shrinks and swells less in width.
  3. Moisture content of the wood at delivery – You should know the moisture content of the decking material when you receive it.  This is measured using a moisture meter.  If you do not check your moisture meter upon your woods’ arrival then you will not know if your lumber has already began to move.
  4. Humidity inside and outside the structure.
    1. Homes in the US that lack humidity control, typically experience levels of humidity from 25 – 65% relative humidity.  This will cause a 6% change in the MC of the wood.  This means if you have a 12 inch wide board it will shrink or expand by a ¼ inch.
    2. Exterior humidity is different.  Most of North America experiences humidity levels ranging from 60-70% in the summer and winter.  If your material is delivered at 6-8% MC then it will experience more than a 2% change in size as it gets used to the EMC.
    3. Species affects the amount of movement Most species of flat grain will change 1% for every 4% change in MC.  The movement values for quarter sawn lumber are approximately ½ the flat sawn values.
    4. Applied finish won’t stop size change- It will not stop the size change but it can slow the rate of moisture exchange down.  Finished wood will eventually accumulate to EMC levels.

Environment and wood species are the main reason as to why wood moves.  When buying your lumber make sure to check your supplier’s environment and to calculate how much your wood will shift in size.  If you want to play it safe, it’s best to buy your wood at least 3-4 days prior to starting your project, so you can let it get acclimated.

Get your free Ipe decking quote directly from the mill. Contact IpeDepot.com today.

Ipe Deck Fastening Methods – Build a Better Ipe Deck

pregrooved decking with ipe clip Ipe decks are great additions to any homes.  Ipe is one of the strongest woods in the world and known to withstand the elements better than any other decking material.  Ipe decks aren’t just strong because of how the lumber is, but because of the ways they are fastened together.

There are three different types of deck fastening for Ipe decking; the hidden fastening method, the face screw/plug method, and the finish screw method.

If you want a screw less and more modern-looking deck then you are going to be  interested in the hidden deck fastening systems made by companies like DeckWise. This method uses strong molded plastics and hardened stainless steel clips that insert into slots cut into the edge of the deck board which then rests on the top of the joist. If your using pregroove decking, then this is the best method to use. It is very easy to install because no other tools are needed. Clips come in three different colors, brown, black, and gray. They also come in several different types; short, tall, kiln dried, extreme and regular. These clips are among the strongest clips on the market. The standard box of Ipe clips goes for $96 and there is 175 clips in each box.Ipe-Clip-Dock-PicWhen using the IDeckWise Extreme fastening method, your deck screws must be installed at a 45 degree angle. Installing at a 45 degree angle will insure a much more stable deck. It will also help stop the possibility of splitting your decking.

The second method, face screw/plug method, uses predrilled 1/8” pilot holes. These holes run completely through the deck boards and into the joist. You will then screw the deck boards down with stainless steel screws. Ipe plugs are then glued into 3/8” holes on the face of the board with waterproof glue. I’d recommend epoxy or gorilla glue. Epoxy is better for gluing posts and can be dyed. You would then gently chisel off any part of the extruding plug with a wood chisel and sand smooth.  It may seem tedious but if you don’t want screws to pop up, covering them with ipe plugs is a great idea.

The third method you can use to build your Ipe deck is the finish screw method. This method uses 8” stainless steel trim head screws which are screwed into the face of the decking at an upright angle. We recommend 2 per joist. This method also suggests screwing the screw in an upright angle. The trim head screw is very small and less noticeable. It also can reduce the risk of stripping your Ipe deck more than the standard square drive.


Deck with stainless steel screws method

If I had to suggest one method to use, it would be the Ipe clip fastening method. It uses the strongest clips and is the most stable. It also doesn’t leave any screw holes on your decks face or have the possibility for nails to pop up.

Get your free Ipe decking quote directly from the mill. Contact IpeDepot.com today.

More Than One Way to Use Ipe

Ipe Playground_thumb

“Wow your new playground is amazing! Where did you buy it?”

“We didn’t. After finishing our new deck we had some Ipe material lying around and decided to build Karen a new swing set.”

“Wow! Ipe? I thought that was only used for decking. I have to tell Bob about this….”

Ipe isn’t your average decking material. It can be used in more ways than one. Because of its brute strength and hardness it can be used in a number of ways.

Here is what some of our customers made out of Ipe:

Indoor Flooring




Dock in Biloxi Mississippi

Garden Bridges



• Gazebos

Playground Equipment



Just like the life span of Ipe, this list can go on forever. Ipe offers you a guaranteed 75+ year lifespan. That’s 60+ years more than your average teak. and decades longer than composites Ipe is also great with dealing with day to day activities along with natural disasters. No wonder cities like Toronto, Green Bay, and even Las Vegas use it for their heavy traffic projects.

Not only can Ipe transform your backyard but also your home as well. With the help from Ipe ship lap or rainscreen siding your home can be recreated. It adds a little flair to your home while acting as a natural barrier to the elements assisting in keeping out unwanted pests.


Get your free Ipe decking quote directly from the mill. Contact IpeDepot.com today.

Ipe Decking – Snack Time for Termites?

Do termites like Ipe decking?

Surprisingly, enough termites and other insects from Brazil and the United States tend to stay away from Ipe Decking.  Not because Ipe decking isn’t delicious, but because this material is extremely dense.  Ipe is so impervious that insects, including termites, don’t stand a chance.  Since they don’t have the ability to actually digest wood, termites usually choose to enjoy softer species, or decomposing wood. Now, imagine you’re a termite. Before you is a piece of Ipe. Since Ipe is 8 times harder than California Redwood (which, as you might imagine makes this type of wood extremely hard and heavy), the choice couldn’t be clearer – Avoid it at all costs.  Also, consider the natural oils’ Ipe secretes helps fight and hold off even the biggest insects from Brazil to the United States.

Ipe Pool Deck

Ipe decking is one of, if not the best material to build a deck with.  It’s extremely strong and sturdy and can hold off any number of pests.  To learn more about Ipe decking check out IpeDepot.com

Ipe Can Withstand Even the Coolest of Climates

As winter is dying down, flowers and newborn animals are beginning to repopulate the earth and that can only mean one thing…spring time!  Time to get your cobwebbed tools out of your garage and start making your yard look beautiful again, and that includes your deck.  If you have a composite deck, chances are there was some damage because of water getting into cracks, mold and mildew growing, etc.  Which means you’re going to have to get it fixed.  However if you built your deck with a strong and dense decking hardwood, like Ipe, rest assured it would still be in pristine condition.

Ipe is known for being an extremely dense hardwood.  That is what makes it great in wet and cold climates.  Because of its density, moisture is not able to create problems that softer deck materials are known for. Therefore Ipe is able to stay in its original form longer and less likely to become damaged.

Ipe decks can be found in some of the coldest cities in North America stretching from the Green Bay boardwalk in Wisconsin to the Toronto Wave decks in Ontario and the Ocean Beach boardwalk in Connecticut.  These three cities chose Ipe decking because they knew Ipe could stand against their bitter winters and monstrous foot traffic.  In the early 2000’s, the Ocean Beach Park residents realized their beloved boardwalk was slowly deteriorating.

Home to dozens of cafes, shops and a even carousel, they knew they needed a strong decking material to host tourists and residents alike.  They wanted a decking material that could withstand harsh climate conditions and resistance to water. They went with Ipe because of its proven 75+ year lifespan, natural decay resistance, and the fact it needs little to no maintenance.  Almost 10 years later, their half mile long boardwalk is still up and running with no complaints of splinters.

Here are some tips to help your Ipe deck make it through a harsh winter:

  • DO NOT SALT YOUR DECK. I REPEAT DO NOT SALT YOUR DECK!  Putting salt on your deck is a nice idea but salt dries your deck which can make it crack.  When boards are cracked moisture can get into the boards where they will later freeze and cause even more damage to your boards.
  • An Ipe stain helps keep your boards from aging.
  • Be sure to brush off any debris or dirt before winter hits because you don’t want it to become trapped in between your decks gaps causing mold or mildew.

To learn more about Ipe and to get a free Ipe quote check out IpeDepot.com.

What Ipe’s Hardness & Strength Mean for You

Ipe is famous primarily because it is one of the hardest and strongest woods in the world.  In fact, Ipe decking exceeds all existing code requirements for exterior constructions.  Here are the official stats:

Hardness: ASTM-D143 tested, approximately 7x harder than Cedar, Janka Side Hardness 3,680 lb

Strength: ASTM-D143 tested, approximately 3x stronger than Cedar, bending strength 22,560 psi

Before we go any further, you may be wondering what the difference is between these two terms.  Hardness is a material’s resistance to indentation, scratching, and abrasion.  Strength is a measure of how much stress a material can withstand without rupturing.

These two traits are closely related, since the same atomic-level characteristics play a role in both.  Although this is not a hard and fast rule and there are exceptions, generally, making a material stronger will also make it harder.

The next obvious question is this: how do these characteristics help you?

Strength can be defined more practically as the thing that prevents deck boards from breaking—one of the main reasons it is so often used in major public attractions across the country, where safety is a huge concern.

A hard decking material like Ipe will keep your deck from accumulating dents and scratches, allowing it to look beautiful for the entirety of its life.  It also makes Ipe impossible for termites and other insects to eat—just imagine if you tried to take a bite out of a rock.  This extends Ipe’s lifespan long past other softer woods.

Building Around Water? Use Ipe!

Many people like to build decks around their swimming pools or hot tubs—or maybe they need to build a dock, or even a bridge.  All of these projects have one thing in common: being near the water increases the risk of a wet surface, leading to potential slips and falls.  As a result, one of the chief concerns for such a project is how slip-resistant the building material is.

Ipe Pool Deck

So what makes a material slip resistant?  It all begins in the cell structure.  Ipe’s cells structure, which is extremely dense, manifests in a very tight, closely packed grain pattern.  This fine texture of interlocking grain gives your foot a good tractional surface to walk on.

But just exactly how “anti-slip” is Ipe?  Well, the wood was ASTM-C1028-89 tested, and the results were good.  In fact, Ipe exceeded the Americans with Disabilities Act requirements for Static Coefficient of Friction in a Wet Environment.

The advantages of Ipe around water don’t stop there, though.  Perhaps more so than any other kind of deck, a deck built around a pool or hot tub is likely to see a lot of bare feet, and who likes splinters?  It turns out that the same qualities that make Ipe slip-resistant also make it resistant to splintering.

Visit IpeDepot.com to learn more about Ipe’s safety features.

Ipe Withstands the Cold in Martha’s Vineyard

People ask us all the time if Ipe, being a tropical hardwood, is suitable for northern climates.  Our answer?  A resounding YES!

Edgartown Lighthouse Boardwalk in Martha's Vineyard

One of the concerns is how the wood will stand up to snow and the brutal cycle of freezing and thawing that can decimate concrete.  This was definitely a consideration when the boardwalk leading to the Edgartown Lighthouse in Martha’s Vineyard was constructed.  With temperatures reaching as low as 25degF during the winter, and an average snowfall of 40 inches per year, the weather is certainly unkind to building materials.  Fortunately, Ipe is naturally water-resistant, meaning excessive moisture won’t get inside, freeze, and create cracks in the surface.  As long as you install it properly, the natural expansion and contraction that occurs between extreme temperatures won’t cause any damage to the wood.

So, if you have a project in an area beset by harsh winters or extreme temperature contrasts, Ipe is a solid choice.  Learn more about Ipe at IpeDepot.com.

Coney Island: A Testament to Ipe’s Lifespan

For decades the name has conjured the taste of hotdogs and ice cream, the sound of screams from a nearby roller coaster, the smell of the ocean.  But did you know that the Coney Island Boardwalk, first opened in 1923, was made of Ipe?  That’s right.  This 90 year old tourist destination serves as the perfect example of Ipe’s unmatched durability.  It has supported the foot traffic of millions of people, as well as the weight of garbage trucks, police cars, and other emergency vehicles.  In 1960, it even survived hurricane Donna relatively unscathed, while a concrete esplanade close by was mangled.

In more recent years, the city has begun replacing the Ipe boards, but that doesn’t mean the wood is no good anymore.  Contractors, designers, and woodworkers all over the country have taken these discarded boards and refashioned them into decks, floors, and furniture.

For example, the Brooklyn furniture company Uhuru created a line of Coney Island-inspired designs, which retail for as much as $7,500 apiece.  The essence of the boardwalk has been recreated at the Barnes Foundation Art Museum in Philadelphia, pictured below:

Looking at these pictures, you might have noticed something: the boardwalk has weathered to a uniform silver patina, but the recycled wood products display rich warm colors.  Just because the wood is decades old doesn’t mean the color is lost for good; a little bit of work and Ipe can look good as new.

The fact that this wood, even after years of wear and tear, is still strong enough for practical use and beautiful enough for more artistic projects should tell you something.  Ipe simply cannot be beat when it comes to longevity and performance under pressure.

Learn more about Ipe at IpeDepot.com.