Kiln-dried timber should be kept dry. This will drastically speed up the drying process. The subfloor registered from 12% to 17% . our question is do we need to replace the floor to avoid fungal problems? How Timber Reacts To Moisture. For more information, see our article comparing Pinless Moisture Meters vs. Pin Meters. This summer I milled several 1.25 boards from a fir log that had been cut around 10 years ago. For joists where the rot infestation has been thoroughly dealt with: it is acceptable to leave the joist as it is. Was told thats not done. I manufacture ice cream sticks and disposable wooden cutlery from European Baltic birch wood in India. A moisture content that is too high will also slow the cure of the SLu and can affect the subsequent floor finish. The angle iron will prevent much warping, and I do plan on finishing all sides (and ends). The other was for a $100 retail gift card. -25% moisture content in a VENTED crawl space. In your area, wood that has been in an environment to a duration of time would be between 6-11%. Whether youre a woodworker making cabinets, a wood flooring professional installing hardwood floors, or if you use wood in construction, wood moisture content (MC) should be always on your mind. Since wood is hygroscopic, it loses or gains moisture depending on the relative humidity of the surrounding air. This is all very helpful information, thanks! So chart would indicate around 9%. Condensation present on the . These tools will give you the confidence that you have done everything on your part to ensure the highest quality in the piece you have built. Being that we live in Central Florida, 40 miles North of Tampa and using this chart page 5 ( https://research.cnr.ncsu.edu/blogs/wpe/files/2016/08/Equilibrium-Moisture-Content-of-Exterior-Wood-in-the-US.pdf) were it states EMC for wood exposed outside for our area of 12.5 to 14.0 when I put the moisture meter to the wood it should be in those ranges if going to be used outside? i cored out a small section of the bottom beam (3 inches wide) all the way down to the foundation. We found out that RH at the final location was under 20%. The next sheet is 21.5% adjacent to 2X4. Mold and fungus in the crawl space can definitely become a problem, but dont be fooled into thinking that a Borate spray HAS to be applied in EVERY situation. 12.5% is gettin there but not quite to the 6-9% mentioned in the article. I live in Atascadero CA and had a coastal red oak tree cut down this past summer. Ive been following your in depth blog on moisture meters for around 1 year now. Logs, siding, shiplap, and T&G must be kiln-dried to stop the wood from shrinking or pulling apart. Would you be able to say anything about the optimal MC range for this specific situation? They many times cite the need for further evaluations by what they call other so called experts. This means your crawl space humidity goes up by about 22 degrees. Would it still be 9% for pressure treated wood? Spruce isnt a hardwood so Im assuming I could get away with a shorter dry time. Wood freshly cut or kiln-dried is always interacting with environmental moisture. You must be careful with a thick slab once you cut it. Thanks for the question. However, it Learn how your comment data is processed. They are currently nearing equilibrium (around 12 MC) and are stored within the house. He wants to install his companys system, seal all external openings around connections, etc. Here is the one I would recommend: https://www.wagnermeters.com/shop/mmc220-extended-range-moisture-meter/, My potential house in North Carolina Fayetteville area was just checked for moisture content in the crawl space. I read your article and really like it. The size of the lumber used for floor joists is the single greatest determining factor in terms of how far a joist can span. On a hot, humid summer day, the air venting into the crawl space could be as much as 75% relative humidity and 85 degrees. And it really helps to pay an HVAC contractor to better seal and insulate the A/C ducts so they dont leak cold air!!! Waterproof membrane . The wood has been kiln dried and packed in corrugate. Dryer wood produces more resistance than wetter wood. Actually floors account for 15% of building heat loss depending on construction. Pinless moisture meters are even easier to use. Call JADE today for a crawlspace inspection and we can give you definitive answers to your crawl space problems! It is best to replace the particle board subfloor. 12% 16% Readings in this range are common to lumber during construction, air dried lumber and healthy residential substructures (beneath first floor in crawl spaces). Use a level to determine if the floor is level within 3/16-inch change per 10 feet. %PDF-1.5 % Make sure theyre aligned with the grain and not across it. This building was constructed around 1966 and this little space appears very dry, in spite of a recent leak from an nearby hot water tank. Moisture contents of 12 to 17% is ok. You dont want to see any subfloor reach about 25% which is where mold will start to grow. This app will tell you the percent moisture content that a given temperature and humidity will equilibrate to. It constantly absorbs and releases vapour into the . I am building a farm style dining table with pecan 2 thick X 8-0 long boards. Here is a link to our moisture meters, thermo-hygrometer, and Smart Logger. Hello, Paul here. A dry reading will be 16% MC (Moisture Content) or below. Im still not sure that whatever they do will produce a good, long-term result, but I need to know what they should be doing to the wood. Hardwood flooring needs to acclimate at least 2 weeks, in service conditions, before it is installed. What is a Proper Structural Engineering Inspection? At that point in time, we did not have a conditioned house. Ideally, you want to check the EMC in the area you will be working on your slab, along with the area it will live in. Very simple and understandable. Keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly. We have a free app called WoodH2O for Android or iPhone. There was a board that cracked along a glue line. Although, in this example, the moisture content of the timber rarely goes above 17%, it is not uncommon for winter moisture contents, in pitched roofs, to peak above 25%. How would be the best way to prevent mold from growing on the furniture. I have an unusual question, if I was to sandwich recycled paper (similar to hardwood floor paper only heavier) between 2 layers of wood as a draft stop what should the moisture content be to avoid the paper absorbing any water and ending up with a mold issue thanks in advance for any info you can provide. In fact, according to M. Steven Doggett, Ph.D. LEED AP, the founder of Built Environments, Inc., wood moisture content as high as 15% can cause corrosion of metal fasteners and at 16% may lead to fungal growth. It is also a good idea to use a moisture meter after the three weeks just to make sure. Thank you for the information, I use a lot of trimmed for for children toys, menu times I use rings of 1-3 inch in diameter, For these purposes I dont care for wood shrinkage or wraping, Two things are important for me that wood will not crack, and that mold wont develop. Is it possible to get a 99.9% moisture reading (using a Cassain GM-200 hydrometer) on a particle board floor which looks and feels completely dry? During the summer months in the northeast region, wood subfloors and floor joists often measure 19. If the wood would really arrive with a MC of 14%, we would not have any problems. Such readings should alert the homeowner to look for a source of excess moisture. The more specific way to know would be to measure the relative humidity and temperature in your homes air and then plug the numbers into a calculator like this https://www.spikevm.com/calculators/logging/equilibrium.php This will tell you what the MC% should be based on your specific environment. Im down to ~13-19% MC near floor level, based on a cheapo moisture meters readings. We have industrial fans going 24/7 to try and dry out the room and also have a dehumidifier running, Ive had the heated floor running in hopes that it could help dry any of the wet wood directly below. Knowing were all the piers are, I can stand on top and feel a small hump in the floors. The purpose of the vapor barrier is to keep moisture away from materials that expand and contract. A contractor is measuring sill plates by driving 2 SS Screws into the wood about 1-1/2 or so inches. Softwoods typically have higher moisture content than hardwoods. Other than causing structural damage, too much water can result in mold growth. As it dries, you should expect slight changes in width and length. What are Acceptable Moisture Levels in Wood? What is the acceptable moisture level for plywood? When determining the acceptable moisture levels in wood flooring before installation, the NWFA states that the flooring professional should establish a baseline for acclimation. Most floor joists are single or double, and most often made with 2x6s or 2x8s. There are water stains on the particle board floor, but the flooring felt completely dry a few minutes after the reading was taken (I didnt see the reading being taken), the floor looks dry in the plumbers photo, the particle board flooring is not noticeably swollen, and it certainly has no flaking or other signs of disintegration or lessening to its structural integrity. Floor joists transfer loads to the vertical beams of the house. Are the measurements of all wood the same? Phil, what are you making with the cedar, and in what type of environment will it be? Am i looking at mold if i dont rip the floor out? If that is the case you need to remove the flooring and examine the subfloor. Wood is used to clean model railroad tracks. If your subfloor is a wood product, make sure the reading is less than 20% on the moisture meter. hL The engineered wood floor appears ok. The normal outside equilibration moisture content (EMC) for Indiana is anywhere from 13% to 16%. Repair is often required when WMC readings are in this range. We had boards that were also cracking/splitting and other places where small pinholes were showing up. WMC of framing members in a crawl space will usually be lowest in late winter and highest in late summer. The wood looks awful, and the staining the did is even worse. However, kiln drying is used to speed up the process. There is over three foot of block above grade around the entire house. Thank you. Water Level Survey: Are You Smarter Than an Egyptian? I had engineered hard wood installed and it is curling at the joints. New roof first week of November. As the airs RH increases, so does the moisture content of any wood exposed to the air. Normal moisture content of wood ranges from 7% to 19%. These are typical readings for exterior wood. The ASTM D4442 standard determines the accuracy of wood moisture meters. Does Brick Veneer Cracking Mean Foundation Problems? In general, 12% moisture or above is too wet to install flooring. Had fans and dehumidifer running for 17 days starting 2 days after leak. Wall Corners-Perpendicular within 1/4" in 10'. Cut in the spring and stacked and dried them over the summer. 15% is too high, at least for hardwoods. If low WMC readings were obtained during the winter, and other signs of high moisture levels are present, obtain additional readings during the summer. Once the wood samples weight stops changing, its weight is compared to what it was before the drying process began. Divide that difference by the sum of the on-center spacing of the floor joists: 118.5" / 16" = 7.40625. Thank you for the helpful article. Screwed 2x4s parallel into the joists as added support. Example: 1.2mm Hickory wear layer 9mm thick plywood compose of 7 layers, 2 layers acacia, 4 layers of Eucalyptus\2 layers Acacia and one layer Poplar. Cracks in Concrete Slabs: Should I Be Concerned? 28% and above Readings in this range are often accompanied by decay damage. The humidity in the room is currently 40! of water/day/1000 sq. As the humidity decreases, the MC decreases, causing the wood to shrink. So, to sum up, Moisture in crawlspaces is bad. This pinless meter is accurate, Ive got 2 other pin moisture meters and all 3 of them read within only 1-3% difference as checked on wood structures. I would have thought that if the floor gave a 99.9% water saturation reading, it would have had to have been noticeably wet. Higher values could mean a wet or saturated material. Longer pins with insulated shafts are designed for the purpose. Its not growing or feeding on the wood. I am not sure if this is pressure treated wood given its an exterior wall and if that affects what these numbers are. Fresh cut trees can have a wood moisture content over 200%, while completely dried wood will have a wood moisture content of 0%. Notches at the end of the joist should be no deeper than 1/4 the depth. Outdoor temp is 99*F. Is this normal? Thanks for the question. Condensation on the inside of a windowpane. Wood Handbook: Wood as an Engineering Material, https://research.cnr.ncsu.edu/blogs/wpe/files/2016/08/Equilibrium-Moisture-Content-of-Exterior-Wood-in-the-US.pdf, https://www.wagnermeters.com/shop/orion-950-smart/, http://www.csgnetwork.com/emctablecalc.html, https://www.spikevm.com/calculators/logging/equilibrium.php, https://www.wagnermeters.com/shop/orion-910-deep/, https://www.google.com/search?source=hp&ei=j6WRW76_NdmT0PEPkN29kAc&q=wood+moisture+content+and+mold&oq=moisture+content+and+mold&gs_l=psy-ab.1.0.0i22i30l3.8963.15970, Restoration Expert Says Moisture Management Critical to Health of Any House or Building, Correct Moisture Content: Critical to Your Woodworking Projects, Mckinleyville Middle Schoolers Learning about Wood Moisture Content, Ambient Data Loggers: Peace of Mind in a Box for Wood Flooring Installers, 5 Things Not to Do When Measuring Moisture in Wood Flooring, Alabama Wood Crafters Share Wood Woes When Overlooking a Moisture Meter. 17 and the flooring is at 6 to 7. Soil is almost always damp. Floor joists support most of your home's weight and play a crucial role in structural integrity. These varying humidity levels of the surrounding air cause wood to not only gain or lose water moisture but to expand or shrink as well. Other signs of high moisture readings include surface mold, evidence of water flows in the crawl space, evidence of water stains or evaporation from foundation walls and columns, evidence of condensation on ducts and evidence of water drops impacting the soil under ducts. Keep monitoring it. When wood is subjected to an environment that is higher in humidity, it will swell or expand. As long as the moisture content does not exceed those readings you should be ok. endstream endobj 79 0 obj <>stream Since your subfloor may be concrete or wood, you should make sure you choose a meter that is specially designed for the specific element you are testing. i did not waterproof the outside of the curb (kerdi), so the wood got wet. can be laid with falls and set downs. Joist spans may not be on the minds of most do-it-yourselfers, but joist spans are everywhere: above our heads in the ceiling joists and below our feet as flooring joists. I dont know what type of floor you have, but if it gets wet enough, about 25% moisture content or higher, mold can grow. Instead of addressing the plumbing and damaged wood, they installed a dehumidifier in 2015. Thank you for the well described article. Because ventilated crawl spaces throughout the Southeast United States allow high humidity and fungus spores to enter the enclosed space beneath the home. Mobeen, If a wooden sample gains moisture, then the sample will increase in size. Thank you, In wood products manufacturing, 6-8% is pretty much the norm, at least in North America. Wood in buildings usually has a wood moisture content of 5% to 15%. Once wood is dried below about 28% WMC, water is not available to support decay, unless the wood is exposed to liquid water. i also drilled into the wood every few inches, several inches deep with a typical drill bit. Furniture grade wood is typically dried to a target of 6%-9%. If there are quite small amounts of moisture in a wall of dense plaster or brick, then a meter will probably indicate over 20% or so and this will be in the 'red zone' or beeps and squeeks may happen. Please give us a call at (800) 634-9961 or email info@wagnermeters.com, if youd prefer. Therefore, just because the wood is kiln-dried doesnt mean it has lost the ability to absorb moisture. Moisture content (MC) in raw slabs can take additional time to reach its Equilibrium Moisture Content. I was thinking 10% MC would be ok but after reading your article Im not sure. The supplier says they dry the wood to an MC of 14%, which is according to them the standard for outdoor furniture. The photo shows a floor that is out of level over four or so boards adjacent to the external wall. I dont know what to believe except the company who installed the vapor and dehumidifier said the vapor barrier needs to be changed out because of all the sewage and drainage stains after the plumbing is fixed. Will the reading be accurate? 18 years ago the moist content (MC) of the beams and joist was 24% in an area of the crawl space that floods in spring. You should be ok as long as the moisture content does not get worse (higher). The front of the . Many timber-framed floor problems can be traced to moisture levels, excessive loads or borer. The electrical current will then move from pin to pin and measure the resistance encountered.