(EMC) than other pieces of wood, depending on its location. Elaine. WME? Hi Larry, We are a joinery company and we have a project here in UAE which is located in another part of the emirates and the humidity in that area is very high especially during summer because it is near the coastal area. to keep the moisture content below 20 percent. Do you have any recommendations on how to prevent mold from getting on the wood? %PDF-1.5 % The average annual relative humidity will play the biggest role in determining what the optimal MC should be. A dry reading will be 16% MC (Moisture Content) or below. Any moisture content measured higher than that might result in movement, such as warping and twisting, once it dries. The excess moisture source should be corrected if found. If the conditions are too wet, dehumidify, and if they are too dry, humidify. If youre wondering how wood can have a 200% moisture content, heres how that works. Subfloor material such as plywood or OSB should measure between 10 and 14% moisture content. As the airs RH increases, so does the moisture content of any wood exposed to the air. Its never constant. Structural flooring for laying direct to joists or battens is a minimum of 19mm thick. Typical moisture content for furniture in a home is 6-9%. Perhaps there is something different about the East and West walls. Wiki User. You should be able to tell where the water reached the subfloor because it will be discolored and may also be swelled up. I just bought a live edge slab of Cherry from a local sawmill that was kiln dried. 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. With regard to mold growing on your furniture, I would have to defer you back to the shipping company as they have more experience dealing with these types of issues. Spruce isnt a hardwood so Im assuming I could get away with a shorter dry time. We have had on/off rain and humidity 80-90% range. Simple and regular maintenance can prevent serious problems developing. Should you check moisture levels on a trailor floor on a massive rainy day? I have a question, I have moisture in the crawl space, we insulated the crawl with closed cell, cannot get the osb subfloor below. We found out that RH at the final location was under 20%. Which do you recommend? Were so sorry for the inconvenience. These are slabs roughly 2 thick. Larry Loffer is a senior technician at Wagner Meters, where he has over 30 years of experience in wood moisture measurement. i also drilled into the wood every few inches, several inches deep with a typical drill bit. That is way beyond fibre-saturation. Will your meters work to find MC levels for composites? All houses now use perimeter foundation so outside contact temperature stays at about 55 F all year. Its mc is 11- 12% . Since wood is hygroscopic, it loses or gains moisture depending on the relative humidity of the surrounding air. Not only did the aggressive notching doom this joist, it affected the structural integrity of the floor system above. Call 256-318-0982 or, Engineering Inspection Mortgage Companies, Unnecessary Panic! Ideally Ill wait until reaching final drying but sometimes I need to use wood before that point. The home inspector failed to report all the sewage stains on the plastic and organic growth on some of the joists have which had been exposed to moisture the whole time even though the dehumidifier has been mitigating the plumbing leaks. With a Wagner L606, I am getting MC readings 12%->15.5% . Heres how it works. my question is, is there a possibility that the wood will shrink because of the weather condition?the wood that we used for the door frames and bidding is beechwood. I wanted to know if is there any standard which specifies the acceptable range of moisture content for wood used in packaging industry like pine wood. Characteristic of this wood easy to absorb of water and have large open pore. We dont know if we still have leaks? Alternatively, you could set up a crawl space dehumidifier and draw the . Be notified when an answer is posted. This is all very helpful information, thanks! How Timber Reacts To Moisture. The floors have started cupping across the entire area with more in some parts. Utilize the chart on following page to record the environmental readings at the time of installation. Standard moisture contents for hardwoods are 6% 9% MC. Hi Davetta, Youll need to contact a local mold inspection company that is certified. During the summer months, when outdoor humidity is high, the hot/humid air enters the crawl space through the foundation vents and condenses on cool objects. You can use our free APP called WoodH2O to help you decide on the best moisture content. What are acceptable ranges of moisture for composite materials like MDF and Plywood, for indoor furniture use? The reading was sky high in the pan and up two tiles high on the wall. We really cant overstress the importance of taking plenty of moisture readings. This means the weight of the water exceeds the weight of the wood by itself. Or perhaps I should advise them to buy Wagner meters, for better accuracy ;-). Well, tile, bricks, and stones are known to have a low water-holding capacity and therefore should be dry. 1. Thanks. This weight difference is then used to calculate the woods original moisture content. could you please guide or on how much should be the Expected Humidity % in high Humid areas like UAE considering these are mostly for Indoor purpose where ACs are on 247 at say 24 Degrees. Floor joists come in dimensional lumber lengths from 8 to 16 feet or more. Do you have a suggestion? My question: what is the complete saturation reading of wood? Does Brick Veneer Cracking Mean Foundation Problems? Any advice would be appreciated. I had a quick looked around the crawl space and didnt notice any structure damage. Question: Just to make sure that you get accurate moisture measurements, has your moisture meter been checked for calibration? Any time water can be absorbed into a material such as wood, drywall etc, its always a good idea to check for excessive moisture, especially if you suspect a leak. I am based in The Netherlands. It is also possible to have moisture content readings over 100%. But this wetness is only surficial. It constantly absorbs and releases vapour into the . The ideal moisture content will depend on the humidity indoors. The fir stock was originally KDd to around 8% but has been covered and stored outside for over a year and currently MC is around 12%. This week, I notice the next pier on the same beam is starting to push up, warping the floor. Hi Moisture Experts, My house is 25 years old located in Oregon City OR (near Portland). During the summer, moisture content readings above . moisture meter testing a floor joist In this image we measure a reading of 37% in this floor joist. The floor immediately felt stronger. I buy many Artificial Trees for our Stores, which has Wood Stems/Barks, mainly produced in China & Shipped to UAE. When I purchase it its soaking wet and Ive always given it a few weeks, stickered and covered for at least 2 weeks, sometimes up to a month, to get it down to around 17-19%. Once the summer cooling season ends, and the A/C is shut off, and the outside air cools, and the humidity drops significantly, the cool dry air now flowing beneath the home dries out the floor joists. Yes, our moisture meters read MDF. The floor installer put the floors down without allowing the boards to acclimate. A general rule of thumb for the coastal regions of FL would be 11-13%MC. Hello, I am renovating my kitchen and installing hardwood floors. Screwed 2x4s parallel into the joists as added support. Any opinions. The new wood was brought in in bundles ~2 x 2 x 6 and left that way to acclimate for ~2 weeks. Good moisture content for softwoods is 10% to 14% moisture. This pin-type moisture meter is one of Delmhorst's most popular models. Sorry, that time of year. As this moisture condenses on the floor system, it wets the wood. I have removed the 1 3/4 edge and resawn to take out the splinter (1/4) re bicuited . look forward to your comments. In contrast, Las Vegas in the drier Southwest has much lower EMC percentages than most other U.S. cities. I would think at least fixing your dehumidifier is a must. I am planning an under-house excursion tomorrow. Not using the correct procedure. water leaked over the edge. We have had very bad cracking in sheetrock and floors. The floor (under carpet) had long-term water exposure supposedly from a shower in the adjacent bathroom (according to the plumber). The optimal humidity in a home is generally 35%-55% and anything under 20% is actually considered unhealthy, as it dries out the skin. A study by Imamura and Kiguchi (1999) showed that wood moisture content in excess of 20% can cause a 5% loss of nail shank diameter in four years and a projected 25% loss in 30 years. It causes decay of the wood structure. Your ideal MC will also depend on the outdoor humidity levels. There is no balancing layer on the reverse of the panels which might obstrust breathing of the panel. Add 1 to this value and round up the answer to the next whole number: 7.40625 + 1 = 8.40625 9 floor joists. The interior was 3/4 BW the tables dimensions were 40x 70 . 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. Had fans and dehumidifer running for 17 days starting 2 days after leak. The National Wood Flooring Association (NWFA) has a chart that indicates the moisture content of wood at any given combination of temperature and humidity. There will most likely be some shrinkage, so if possible, choose the clearest boards possible to lessen the possibility of any major cracking. The company they hired measured 47% in the wood and declares that this must be ripped out and replaced. The plywood setting is .57. This article is really helpful. The humidity in the room is currently 40! Sagging or Uneven Floors Solutions. If that is the case you need to remove the flooring and examine the subfloor. If the subfloor is not acceptable, it can often be overlaid with 1/2 -inch plywood. Typical humidity levels inside a home is between 40 to 50%. Seattles EMC ranges from 12.2% to 16.5%. And would it be normal for the MC to vary from board-to-board and one end of a board to the other? Floors should be: level within a 3mm deviation per 1m for floors up to 6m across (measured at the furthest points across the full width of the floor) a maximum of 20mm out of level for floors over 6m across flat within a 5mm deviation, measured using a 2m straight edge with equal offsets. First, test the moisture level of the subfloor. Notches at the end of the joist should be no deeper than 1/4 the depth. 17 and the flooring is at 6 to 7. P.O. 10? Live in Tn. This can be a problem once installed in furniture or a floor. Hello Folks, I am new to wood turning and do not have a ready supply of dry/seasoned (my wood is green) wood. What are Acceptable Moisture Levels in Wood? A company sealed off the foundation vents and removed all the insulation from the crawlspace with the humidifier mitigating the moisture from the leaks. The EMC in the recommended temperature/humidity range coincides with the 6% to 9% range used by most flooring manufacturers during the manufacturing and shipping process. If I dry too much, theres discoloration and breakage of product during polishing. 0 WM=8DBaHh10tIKR/OH}X5Kpt'_]4Mfg9@w8~ n$R This means a very absorbent wood can retain more water, weight wise, the weight of the wood itself. 20% 28% Readings in this range indicate that conditions are border-line for decay. Crawl Space Inspections: Once a Year Keeps the Contractors Away! The three main sources of moisture: Condensation, Foundation wall transfer, and leaks. A Brick Veneer Crack Tragedy: A True Story, Spraying for Mold on Floor Joists: Pest Control. Thanks for the the information, very detailed and useful. Condensation on the inside of a windowpane. Can carpet be reinstalled? There is only so much moisture a piece of wood can give up, over time, before a failure occurs. Thanks for the question. The conversion puts the adjusted MC between 9.5 -> 12%. This is expensive and its ridiculous. 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. . Damn those shop classes I didnt take. Should I wait? If you want, just give me a call at 800-634-9961, ext 225. This is the standard in the construction industry. I believe you are asking for the percent moisture content (humidity) of South African woods. I read your article and really like it. Because of the different materials involved, they will react differently to high heat, thus giving you an un-even plywood surface. Two questions I need a reliable, easy to use meter that can cover all species as I now have a portable mill and that can be used for treated. Back to top. Once the wood samples weight stops changing, its weight is compared to what it was before the drying process began. Does it have another common name? For joists where the rot infestation has been thoroughly dealt with: it is acceptable to leave the joist as it is. primer, the moisture vapor transmissions rate (MVtr) from the substrate should not be in excess of 5 lbs. Its hard to gauge anything off of a cheapo meter, but if and I mean if, we were to assume it was reading effectively, the numbers are too high. They are putting desiccants in the container to absorb the moisture but we feel its going to be a long time enclosed in the container without any air circulation. Thanks Phil. The engineered wood floor appears ok. Because ventilated crawl spaces throughout the Southeast United States allow high humidity and fungus spores to enter the enclosed space beneath the home. We have started to import teak outdoor furniture from Indonesia into Europe. Any thoughts as to what the issue was with the first install so we dont have the same issue again next year after we go through a new install? Grain orientation matters wood using pins while the MDF uses pinless? These WMC readings are usually provided by pest control operators, and are included in the termite letter (form CL-100 Official South Carolina Wood Infestation Report). An MC in this range, therefore, is considered sufficiently dry for exterior in-service wood. Most types of wood species will mold above 25% moisture content, including pine. These are typical readings for exterior wood. Hello I moved into my new home in June of 2018. Since the cold weather has come on, the organic growth has gone dormant, but a contractor noticed joists with distinctive moisture content where there are definitive separations between dry and wet looking wood. My meter tells me anything above 12% is wet but I cannot find any source of leaking or signs of water. Instead of addressing the plumbing and damaged wood, they installed a dehumidifier in 2015. You are correct, furniture grade hardwood is typically dried between 6 to 9%. ( 55 days transit by sea) What should be the moisture content while loading in Containers? Failure to do this will result in warping, cracking, and other problems after the construction of the wood product. Floor joists transfer loads to the vertical beams of the house. You should be able to specify a lower moisture content. 9Chrv;plt[nh%:fOl8e^5e cM(?=6?y8{6uZkpz[TgLXD9feUm.L;l7:5C:hf=tE&U[&8 ^ wu*Vz*##;PKk? It will be there for a few months before I begin working on it. The manufacturer of the oil-based poly should have a specification on the maximum allowable moisture content of the wood. Sorry that this is so long-winded and I thank you in advance if you are willing to address this question for me. It is not fair to ask the seller of this home to pay some pest control firm to spray Borate on the floor system. Hug the ones you love when you see them! Moisture was around 25% when milled, and the ends were sealed. We dont know if we still should be having a commercial drying process? You will also see that the healthy wood moisture levels of 10% - 16% occur when the relative humidity is between 55% and 80% at 70 degrees. The wood joists are not soaked wet, its just a light film of moisture on the wood members. Post and beam constructions don't have to be kiln-dried but should be air-dried. Do you see any dangers of using poly with a MC of around 12, or am I risking adhesion failure especially if the wood does end up shrinking dimensionally? 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%. Observed water leaking along seams of several sheets of original plywood in attic. (864) 506-4701, South Carolina Residential Construction Standards, http://www.rlcengineering.com/wp-content/uploads/2019/04/RLC-Engineering-1.png. However, kiln drying is used to speed up the process. Therefore, just because the wood is kiln-dried doesnt mean it has lost the ability to absorb moisture. You wrote that 15% humidity may induce mold? We will be having a deck built off my woodshop. Have I been wrong? Would you be able to say anything about the optimal MC range for this specific situation? Remember that the meter assumes it is reading timber. If so, then you'll want to know. Your email address will not be published. Good luck. After all, the wall is in contact with damp soil. You will want closer to 6% in the drier climates and 9% MC for the more humid climates. I am shipping teakwood furniture from Indonesia to California. They delivered the wood one day, and began to stain and install it over the next two days, finishing on the 6th day. The NWFA recommends testing wood subfloor moisture in at least 20 locations per 1,000 sq. I really need to know as I am getting so many different opinions Thanks. One of our new line of moisture meters will help locate areas of high moisture, if it still exists. Brick Veneer Homes: Are They Really Worth the Headache? Can I get a away with this? It does the same for wood, and is especially hard on softwoods, such as pine or fir. We have had an abnormally wet spring and part of summer. The builder's warranty representative came out and measured the moisture levels with a moisture meter. Good luck. hj0Ed=h].J-)_q},jR3$\ eH"wCk)E)J8 The sink vanity is made from typical laminated particle board, and Ive been trying to dry it in place using a dehumidifier and sealing the area off. The home inspectors working for fees today seem to have one primary motive in mind: to cover their liabilities. The ideal moisture content for hardwoods is between 6% and about 9%, depending on the ambient conditions around the wood. It is possible, in some species, to have a moisture content higher than 100 percent. The ceiling in the bedroom above the chimney breast shows signs of damp however doesn't feel damp/moist. Wood moisture content between 0% and about 28% is dependent upon the relative humidity (RH) of the air. Structural Repairs Dont Have to Be a Nightmare! I called them back out in August of 2019 because after installing a humidifier and in the prime of humid season, the floors were showing no signs of improvement. 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. Cracks in Concrete Slabs: Should I Be Concerned? When it comes to the moisture content of plywood or dimensional lumber, an MC of 17% to 19% reduces the overall strength of plywood, and an MC of 20% or more reduces the strength of dimensional lumber (i.e., lumber cut to certain predefined sizes, such as 2x4s). However, this range will vary slightly according to the geographic region because of varying RH levels. If the MC of plywood is above 20%, can it be redried in a kiln or would that harm the glue? Under the floor. Sometimes moving the air around is enough to remove moisture and dry surfaces. Because the moisture content of wood is equal to the weight of the water in the wood divided by the weight of the wood without the water, its possible for the moisture content to exceed 100%. I think mine is +-3% Is it possible being near the door just means greater humidity and there isnt actually a leak? You can Google moisture content of wood necessary to support fungal growth and see for yourself. I-joists are comprised of top and bottom flanges, which resist bending, united with webs, which provide outstanding shear resistance. It's a direct proportion: an 8-in. The acceptable moisture levels in a crawl space are between 30% and 50%, with under 55% being the ideal. So what do you think is the ideal moisture% I should dry them to before rotary polishing them? We built our home from ground up and have a sealed crawl space dehumidifiers, etc In January of 2019, we had our builder and hardwood floor contractor come out because our hardwoods were starting to separate a lot. Thanks for any help you can provide! moisture will typically measure 7-10%. The SG setting is on the card that comes with the meter. 800-347-7260 Fax. Writing all the way from Australia, Steven. Waterproof membrane . My question for you is, now that it is stained, can I still get an accurate MC? Again, the correct moisture content will depend on the surrounding conditions. In the Midwest, the EMC of wood or lumber in Des Moines, Iowa, ranges from 12.4% to 14.9%. My builder and flooring contractor asked for me to give the hardwoods a season to acclimate and they would surely move back together in june/july time frame. I know the rule of thumb is 1 year of dry time per inch of thickness of wood. This means your crawl space humidity goes up by about 22 degrees. I live in upstate South Carolina. How long will it take to get to the ideal moisture reading and is it better to be stored in a garage or inside a house? My question is microwaving twice turned bowls what would be the general rule of thumb for a target by weight. Even at this, the estimate would be the high end of MC% prior to shipment, but only rough estimate. Ive been following your in depth blog on moisture meters for around 1 year now. Call 256-318-0982 or contact us today. I am not familiar with the particular moisture meter the plumber was using, but assuming it is correct, that moisture content is way too high to install new flooring. Percent moisture content in wood is the ratio of the weight of water compared to the overall weight of a piece of wood. Toilet overflowed and moisture meter is reading 30% in worst area. SE, Huntsville, AL 35802. Because pinless meters scan the woods surface and cover a larger area than pin-type meters, they provide a more thorough picture of the woods moisture content. Colorado is cold and dry. I had a redwood deck, and they replaced it with Douglas fir (without my approval, but thats another issue). If the middle is wet, you may experience cracking/splitting if dried too fast. What is an FHA Permanent Foundation for Manufactured Homes? Indoor humidity is around 50%, indoor temps around 70 degrees. I live in coastal South Carolina .we are definitely afraid of mold formation. Last reviewed: 12 Sep 2021 Last published: 12 Sep 2021. The home inspectors working for fees today seem to have one primary motive in mind: to cover their liabilities. Water was coming out of this outlet and onto the floor? When exposed to a constant RH, the moisture content of wood or lumber will come to equilibrium with its environment, resulting in an EMC for that species of a wood-based composite. A wood moisture content of 47% is too high. guide-standards-tolerances.pdf. at one spot, its 40%. Outdoor temp is 99*F. Is this normal? Am i looking at mold if i dont rip the floor out? These are typical readings for exterior wood. Allowing the wood to acclimate in the final spot before building, really isnt possible because it is 8 hours away, and I cant take a week off to go up there and build the table. Thanks! This will drastically speed up the drying process. Do you think its to early to start working with it.If so how many yrs will it take to get to proper mc so i can work with it. If the leaks have damaged the sub floor or joists, call a licensed general contractor for repair. Over a year ago, I re-shim all the piers with metal shims. One type of wood moisture meter. The National Wood Flooring Association (NWFA) has specific installation guidelines for wood flooring and how they relate to moisture content. You mentioned the humidity outside is 55%. The excess moisture source must be immediately corrected, and the situation carefully monitored until the WMC returns to the 12-16 range. With a concrete subfloor you should use a digital hygrometer, which needs to be left in place for at least 24 hours. What is a Proper Structural Engineering Inspection? In an air conditioned house the wood floor. Wall Construction Flat-or no more than 3/8" in 8' (bulge) But none of the contractors abide by the framing codes, nor do the city officials. Wood Rot in Crawl Spaces: Whats That Smell in My House. Take the readings in at least 20 spots per 1,000 square feet of flooring and average the results. He wants to install his companys system, seal all external openings around connections, etc. I had it milled into 2.25 slabs and I stacked it on a deck area. They many times cite the need for further evaluations by what they call other so called experts. You mentioned it was installed just 3 days after it was delivered. What humidity content should cedar be at for proper gluing. Headers, columns, and joists are rotting. Your subfloor moisture level should be no greater than seven to nine percent when you are installing flooring. When it hits the cooler air of the crawl space, it increases the relative humidity by about 2% per degree! Varying humidity levels can cause wood to lose or gain water and shrink or expand. Soil is almost always damp. Then placing his pin meter on the screws. Next, check the moisture of new floorboards. Did the Contractor mention anything about the structural strength of the joists? You can check for moisture by using a moisture meter. Using South Carolina Residential Construction Standards to Solve Problems, Website by Integritive Web Design :: Asheville, NC. Understanding the effects moisture has on timber, as well as acceptable moisture levels in wood flooring, will keep your timber floor looking pristine throughout its lifetime. This only occurs when wood changes moisture content below the fibre saturation point. I so appreciate your treatise on this issue. I did not find any information on Matumi. Am I possibly getting false positives? Thanks for the question. The interior wood moisture level should be 12% or lower before painting. Your table may have been a little too high in moisture, hence the crack as it dried slightly in the drier environment. 15% is too high, at least for hardwoods. i used my dremel with a shaping bit about 1/8 in to cut vertical slits or vents about an inch deep and a couple of inches tall into the bottom 24 and have kept a commercial floor blower on the wood several hours a day for more than a week yet, the number is not going down. I also applied Boracare (boron) that has stopped minor beetle damage. Its not growing or feeding on the wood. with the spring thaw, i was one of the lucky ones that got water in my basement. Thank You. Decay fungi need liquid water to grow. The interior home conditions are, AC running at 68-70*F. Exterior wall condition 104*F as checked with an IR thermometer of East wall not in the sun. Water Level Survey: Are You Smarter Than an Egyptian? With a degree in Computer Systems, Larry is involved in both hardware and software development of wood moisture measurement solutions. Your help for resolving this issue would be highly appreciated . This must be done before attempting to dry out the wood. This document describes the meaning and use of readings from a wood moisture meter. Im looking for the % number that will be my upper boundary for oil application Would 12% be ok? I dialed the 800 number for Wagner meters and all I got was two sales pitches for a Life alert type device. To make sure the wood is properly dried, he always uses a moisture meter before working with it. Thank you. Floors-1/2" in 12' or 3/16" in 4'. My house is 24 years old. Use a wet/dry shop vacuum, sump pump, or rags to clean up standing water or excess moisture from the floor and from the surface of the wood. Both slab-on-ground and suspended concrete floors for wet areas: are deemed impervious when steel trowel finished or polished. h26P0Pw/+Q0L)66 For instance, the subfloor may appear to be dry on the surface, but still have elevated moisture within the panels. Since water conducts electricity and wood doesnt, the dryness of the wood can be determined by the amount of resistance to an electrical current.