Cresdek FAQ's

HAMBRO FOREST PRODUCTS, INC.

Cresdek® Cres-X®

FAQ Table of Contents

How do I properly gap a new floor ?
Where can I find an MSDS?
Can I install a hardwood over Cresdek?
What about water damage?
CRESDEK VERSUS PLYWOOD and OSB

How do I properly gap a new floor ?

An expansion gap of not less than 1/16" and not greater than 1/8" is recommended at all seams whre two panels come together. Cresdek panels that have undergone a minimum of 20 days of acclimatization at the factory in Crescent City, CA can be lightly butted together without a gap. Acclimatized panels can be identified by a SA marking stenciled on each unit.

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Where can I find an MSDS ?

Material Safety Data Sheets can be found by the links below.

Cresdek Cres-X

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Can I install a hardwood floor over Cresdek?

Yes, you can install hardwood flooring over Cresdek. Please review and follow the attached installations instructions.

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What about water damage?

Even after repeated exposures of several days, Cresdek will more than meet the minimum standards required under the ANSI A208 standard that governs the quality and performance of single layer structural floor decking used in manufactured home construction. The most important thing that must be done with any home that is exposed to water is to get the home dried out and do it as soon as possible. This is not done just to protect the floor decking but to also protect the many other dry components of the home. When the home is being dried out it is extremely important to not only dry out the top of the floor (all floor coverings should be removed during the drying process) but also make sure moisture intrusion did not occur within the floor cavity below the floor. The enclosed area underneath the home must be inspected and by this I mean the area between the bottom of the floor decking and the bottom board (often a black plastic membrane) enclosing the bottom of the home and protecting the insulated area beneath the floor. Insulation is like a sponge and can trap and hold water for a long period of time. Water trapped in the insulation cavity under the floor must be dried out to protect all the wood and dry components of the floor and home, not just the floor decking.

Virtually all wood flooring products will expand when exposed to water and/or high humidity because wood is hygroscopic which means the wood cells naturally take on water and expand and do so relative to the wetness of the immediate surroundings. Drying out a home exposed to water can take up to three or four weeks. When done properly and plenty of adequate ventilation is required. This is because although wood may appear to be dry on the surface it is still wet inside. And again, this includes all wood components of the home under sever and extended water exposure. It would be normal to have the floor decking expand and show some degree of waviness or buckling or warping. This is normal and will occur with all floor decking, including OSB or plywood. The floor will usually return to flat once it has been given adequate time to dry out. Occasionally, when a floor does not come back down to flat after exposure to water, it may be necessary to kerf the seams and/or kerf the panels over individual joists in the field to get the floor to lay flat again.

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CRESDEK VERSUS PLYWOOD and OSB

Comparison basis.

Panel sizes: Cresdek 96” x 168”

Plywood 48” x 96”

Floor dimensions: 14’ wide x 54’ long.

A plywood floor requires 30 individual pieces of various sizes (2 pcs 2’x4’, 6 pcs 2’x8’, 2 pcs 4’x4’ and 20 pcs 4’x8’) to build the same floor that 7 pieces of 8’x14’ Cresdek cover. The higher the number of panels required to build a floor the greater the risk of floor squeaks and show through (telegraphing) of the seams, gaps and corners through the floor coverings. Homebuilders and homeowners often are not aware that one of the primary reasons larger particleboard panels made tremendous inroads into the manufactured housing industry was because of the extremely high rate of floor squeaks and floor covering telegraphing that occurred with 4’ x 8’ plywood panels. This fact remains true today and is also true of 4’ x 8’ OSB.

With plywood 4' x 8' T&G or OSB) you end up with 206 lineal feet of seams while Cresdek has only 81 ½ lineal feet. Plywood or OSB doubles the risk of seams showing through the floor covering.

When 4'x8' T&G plywood or OSB panels are installed, 66% of the adjoining seams are loose and unsupported. Out of a total of 206 lineal feet of seams, 138 lineal feet are a "floating" joint. Floating joints are the primary cause of floor squeaks and floors constructed with 4'x8' T&G panels have high rates of floor squeaks. Floor squeaks are virtually eliminated when floors are built with large Cresdek or Cres-X single layer structural panels

Plywood and OSB have 78 panel corners in the field of the floor. There are no panel corners in field of Cresdek. One of the most common complaint homeowners have with floors built of 4’ x 8’ T&G plywood or OSB concerns the corners and seams of the panels showing (telegraphing) through the floor coverings.

Cresdek offers a surface that is 18% to 25% harder than plywood or OSB when tested under the Janka Ball Hardness test.

Cresdek is solid throughout the thickness of each panel. Cresdek does not have any “allowable” defects as is defined and allowed under published plywood manufacturing grade and production rules as established by the Engineered Panel Association (APA). “Allowable” defects in plywood such as knot holes, veneer splits and core voids have increased in both size and quantity over the years as the industry trade association modified the manufacturing grade rules to accommodate the lower grades and smaller size logs available to convert to plywood today. The quality of plywood you buy today is nowhere near the quality your grandparents or parents were able to buy in the past. Today, under the published “allowable” and “open” defects grading rules governing plywood production, knot holes, veneer splits and defects up to 1 ½” wide are allowed.

Plywood and OSB sold as 3/4" actually measures 23/32” or 0.7188. Cresdek 3/4" measures 0.750” while 5/8” Cresdek measures 0.625” thick and plywood and OSB measure only 0.594" thick. (19/32")

When real-world performance requirements and consumer cost benefits are factored into the equation Cresdek proves to be a better choice than plywood or OSB. Cresdek must pass rigorous physical property and performance testing to gain certification for use as single layer residential floor decking. Under required certification testing, Cresdek must hold a minimum concentrated load of 600 pounds (lbs) when applied with a 1” diameter disc at the most critical location (centered between the supporting floor joists) . Continuing the loading beyond the 600 lbs minimum is NOT required. However, we voluntarily continue to increase the load until failure occurs and Cresdek sustains loads averaging over 800 lbs.

To place an 800 lbs concentrated load into human perspective, a 1” diameter disc has a surface area of 0.7854 square inches (si) so a load of 800 lbs equates to a load of 1,018 lbs per square inch (psi). However, the scientific community regards a 3” diameter disc as representing the actual loading area created by a human foot. Therefore, a 600 lbs human, standing on one foot would create a load of just 85 psi! Installing plywood or OSB floor decking is nothing more than significant construction overkill. Plywood and OSB cost more to purchase and install while offering no significant performance advantage.

The most demanding concentrated loading on any floor is likely to be created by the supporting legs of a grand piano. To get an expert opinion on the topic of pianos and floor decking in manufactured homes we called Jimmy’s Piano Moving in Sacramento, CA and talked to the owner, Mr. Jim Hinkson. Located in one of California’s major population centers, Mr. Hinkson has been moving pianos for more than 30 years. Mr. Hinkson stated that he “has moved hundreds of pianos into manufactured homes, even on one occasion, moving a full sized 9’ grand into one”.

During the 30+ years of moving pianos Mr. Hinkson has never encountered a single floor problem nor floor failure when moving a piano (full sized grand or otherwise) in or out of a manufactured home. It would be a safe bet that most of these homes were constructed with Cresdek since every builder located in the Sacramento and Woodland, CA area installs Cresdek floor decking and has done so for over 30 years. Mr. Hinkson also stated that it was rare for a full sized 9’ concert grand to be placed in any home, site-built or manufactured. Because, nearly all people that purchase a grand piano buy a model no larger than 5’6”.

Mr. Hinson’s professional experience underscores the strength and performance of Cresdek floor decking. It also provides factual real life evidence that the performance of Cresdek is reliable and exceeds the most severe demands of builders and homeowners.

Complaints with floors built with 4’x8’ T&G plywood or OSB are high compared against Cresdek because of the high rate of telegraphing (show through) due to excessive seams, required gaps, corners, fasteners, face defects and the fact over 30 individual panels of various sizes are required to build a floor (60 pieces to build a two section home) and floor squeaks.

Although technically a particleboard, Cresdek should not be compared to typical particleboard products. Under the American National Standards Institute ANSI A208.1-1999, the production standard for particleboard, Cresdek is a D-3 grade product and the D-3 grade is the higher of the two grades approved for use as single layer floor decking. D-3 grade particleboard is among the strongest of the 12 grades approved in the ANSI standard. D-3 floor decking has the third highest rating for Modulus of Rupture (MOR) at 2,828 psi. It also has the highest rating for Modulus of Elasticity (MOE) at 449,600 psi. Also, the allowable linear expansion is the lowest (lower is better) at 0.30 % maximum average.

Cresdek is produced one panel at a time in single opening presses. This production advantage allows us to manufacture Cresdek to a final target thickness that can be shipped without sanding. Eliminating sanding allows each panel to retain the “skin” of resin and wax formed on the face and back of each panel during the production process. This “protective skin” increases water resistance. Sanded products like plywood and OSB open the raw surface of the wood to moisture intrusion and the sugar in the exposed raw wood promotes the growth of mold and mildew when wet.

Plywood is typically more expensive for a builder to purchase. In addition the labor to install 4’x8’ panels is considerably higher than the cost of installing large Cresdek panels. Considering the delivered price of plywood, the additional installation costs, a wholesalers mark-up plus the mark-up by the builder and the retailer a plywood floor will typically cost $1,500 to $3,000 more than a Cresdek floor (normally closer to the $3,000). So, if you finance the $1,500 at 7% over 30 years you will pay interest of $2,093 plus the principal of $1,500 for a total of $4,185. Or, if the cost is closer to $3,000 as we expect, you will end up paying $4,185 in interest plus the principal of $3,000 for a total of $7,185. However, if your finance rate is higher than 7%, which would not be unusual, or the cost of the floor is more than our estimate, you will end up paying even more. And, for all the extra money you end up spending you are paying for something that does not improve the quality and performance of your home nor your quality of life. Better from a long term to take the money and place it in a long-term investment so you have the money working for you. Or, use the money to up-grade your home with something that will truly add value and/or improve your quality of life.

The most common question about particleboard relates to water resistance. We have been producing Cresdek floor decking at our Crescent City, CA plant since 1964 and we produce floor decking exclusively and are the only plant in North America to do so. Since 1964 Cresdek has been installed in over 1 million homes and we have rarely encountered any floor decking degradation due to direct or indirect water exposure. Certainly, no more so than we have seen with the water damaged OSB and plywood floors we have inspected during the last 42 years. It is statistically estimated that water related problems, and this includes all water damage, not just water damage to floor decking, that occur with manufactured homes (HUD or Modular) is estimated to run at approximately 0.001%. This means that during 2005 when the HUD Code manufactured home industry produced a total of 146,881 homes at most there would have been around 147 homes that may have displayed any water related problems. And, more than half of these homes were constructed with OSB or plywood). Also, the probability that any individual floor would be exposed to multiple incidents of water exposure is so low as to be virtually zero. The risk of water damage to a floor constructed with Cresdek is no higher than it is for plywood or OSB. And, in many other ways, relative to construction quality and long-term performance, Cresdek outperforms both plywood and OSB.

Unlike many floor decking products including nearly all plywood, the surface of Cresdek is not sanded after production. Consequently, the “skin” of resin and wax that encapsulates the surface layers of Cresdek protects each side of the panel increasing the moisture, mold and mildew resistance. Uncoated, sanded or raw wood fiber is more susceptible to water damage and more likely to support the development of mold and mildew. Units of Cresdek and Cres-X full mat panels (before being cut to size) are stored outside with top and bottom cover sheets in a area where annual rain fall is over 75". (A testament to the durability of these high quality structural panels.)

During a 24 hour water absorption test conducted by PSI, an independent third party testing agency, plywood absorbed 36.2% water or 306% more water then Cresdek. The plywood also swelled 4.7% or more than 123% greater than Cresdek.

Since we began producing Cresdek during 1964 at our Crescent City, CA plant we have stored all Cresdek in full mat sheets outdoors year-round with each unit covered with top and bottom cover sheets. And, Crescent City, CA is an area where annual rainfall averages 75”! I know of no manufacturer of plywood or OSB that can make the same claim.