Wood shrinks or swells as its moisture content changes, but only when water is taken up or given off from the cell walls. You will however, need to become familiar with reading your local floor joist span tables for floor beams, floor joists, window and door lintels, ceiling joists, roof joists, roof rafters, and roof ridge beams, as well as the sizing and spacing of wood studs tables. In an air conditioned house the wood floor. If you know such International or Amercan or any other standard please let me know. Larry Loffer is a senior technician at Wagner Meters, where he has over 30 years of experience in wood moisture measurement. What Are The Acceptable Moisture Levels In Wood Flooring? If you need further clarification http://www.nwfa.org is an excellent source. PDF Moisture and Wood-Frame Buildings - Healthy Heating This week, I notice the next pier on the same beam is starting to push up, warping the floor. Substrates must be protected by: Why and how can I say this? Installers should also measure the moisture in wood subfloors and concrete slabs as they can also affect wood flooring. of the average flooring moisture content that is being laid). Three years ago, the floor sank in a heavy traffic area and an engineer told me Masonite was used to shim and had compressed. Different wood? If the leaks have damaged the sub floor or joists, call a licensed general contractor for repair. Structural Repairs Dont Have to Be a Nightmare! I am based in The Netherlands. A Brick Veneer Crack Tragedy: A True Story, Spraying for Mold on Floor Joists: Pest Control. INSTALLATION GUIDELINES: WOOD SUBFLOOR - Wego International Floors A general rule of thumb for the coastal regions of FL would be 11-13%MC. 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. Cut in the spring and stacked and dried them over the summer. I had a redwood deck, and they replaced it with Douglas fir (without my approval, but thats another issue). Perhaps better drainage around your house will do the trick or treat. Would you be able to say anything about the optimal MC range for this specific situation? What humidity content should cedar be at for proper gluing. Im not sure which part of Europe you are from, but typically the Indonesian climate is very humid compared to other parts of the world. 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. : Mold & Fungus In the Crawlspace. Because ventilated crawl spaces throughout the Southeast United States allow high humidity and fungus spores to enter the enclosed space beneath the home. Here current humidity is 76%. At that point in time, we did not have a conditioned house. So please help us to know what should be required moisture level in Acacia board in final product if we need to restrict wood movement at Colorado . Replacing Subfloor: What You Should Know | Hunker Your email address will not be published. Substructures with WMC in this range may show decay or rot in floor joist, sills, and subflooring. The normal outside equilibration moisture content (EMC) for Indiana is anywhere from 13% to 16%. The rim joist and floor joist sit right on the block. How would be the best way to prevent mold from growing on the furniture. While the surface of the floor might feel dry, there could be higher moisture inside. The MC varies from 7% 13.5% around the exterior door on dry days and 10%-16% during rains. The humidity in the room is currently 40! If the moisture is less than 20% and the floor joists are structurally sound, like the joists at this home, there is no need to worry about any fungal staining that might exist. However, the company who maintains the dehumidifier said he tested some of the joist which he said only registered 10 on his device. Engineering & Inspection Services, Licensed PE - Alabama & Tennessee, JADE Engineering & Inspection | 5405 Whitesburg Dr. Here is a link to our website for more information: https://www.wagnermeters.com/shop/orion-950-smart/. Hi, we live in a coastal area, had a recent water leak, and a hard wood floor MC is measuring about 25% the water did not contact this area directly. To establish a baseline for wood flooring acclimation, the installer will need to calculate the optimal moisture level of the wood by dividing the regions high season and low season EMC. On a hot, humid summer day, the air venting into the crawl space could be as much as 75% relative humidity and 85 degrees. This water may come from condensation, roof leaks, plumbing leaks, or contact with the soil. Instead of addressing the plumbing and damaged wood, they installed a dehumidifier in 2015. 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. Add an answer. However, kiln drying is used to speed up the process. This is all very helpful information, thanks! I just bought a live edge slab of Cherry from a local sawmill that was kiln dried. Water Level Survey: Are You Smarter Than an Egyptian? We found the problem and the leak was resolve quickly! Truss Uplift: Who Would Have Ever Thunk It? A good moisture content is between 6 9% for Colorado. Pin-type meters use penetrating electrodes and measure the woods moisture content using electrical resistance. 24 and 26 framing studs should measure 19% moisture content or less. My question is regarding finishing. Does it have another common name? Wood is used to clean model railroad tracks. Floor Joist Calculator Either one should be acceptable for finishes. Electronic moisture meters for damp diagnosis in buildings My last Wagner was appropriated by the individual who appropriated other tools out of my old sho. Also, there is a risk of mold. It is best to obtain a wood moisture content that will match the environment. (He didnt cite a figure.) I would also consider the environment where the table will live. . Moisture was around 25% when milled, and the ends were sealed. If an interior location has an average RH of 40-52%, wood placed there will have an average EMC of 8-9%. thanks so much in advance. info@rlcengineering.com Kiln-dried timber should be kept dry. Should it be less? While playing around with my pinless meter and checking the interior East and west walls on hot days, I notice the moisture content being very high 60% mc to off scale. Ideally Ill wait until reaching final drying but sometimes I need to use wood before that point. Seattles EMC ranges from 12.2% to 16.5%. A dry reading will be 16% MC (Moisture Content) or below. Logs, siding, shiplap, and T&G must be kiln-dried to stop the wood from shrinking or pulling apart. When you do this, you not only ensure that the entire batch is okay on average, but youre also far likelier to catch boards that are statistical outliers and could cause problems. The average annual relative humidity will play the biggest role in determining what the optimal MC should be. This is expensive and its ridiculous. My question is microwaving twice turned bowls what would be the general rule of thumb for a target by weight. Very educational! Thanks. I am not sure if this is pressure treated wood given its an exterior wall and if that affects what these numbers are. Thank you. Wood Moisture Content is the weight of water in a piece of wood expressed as a percentage of oven dry weight of wood. Does that seem normal. I suggested replacing my dehumidifier (Sears brand, bucket collection) which has been inoperable this past year. Its mc is 11- 12% . These home inspectors are insecure and inexperienced. To achieve this, Acceptable Solution E2/AS1 says that, on near-level sites, the floor level must be no less than 150 mm above the crown of the road or the lowest point of the boundary. Wiki User. About 5/16 penetration into the wood measures 8% using pins only. hello I been getting very sick in my home so I had my manger do a mold and moisture test which came back high level of moisture levels which a contractor wants to take the sub floor up and 2 to 4 inches of the wall but my apartment manger is not releasing to report and hes is saying the spore test didnt pick up any mold spore question is it safe for me and my family to be in the home with high level of moisture in the restroom which the floor have been really soft for over 9 months now as well as the kids bedroom where a pipe burst. Limit the length of notches to 1/3 of the joist's depth. You are correct, furniture grade hardwood is typically dried between 6 to 9%. What is "Acceptable" Dry? | 2021-06-02 | Restoration & Remediation Magazine Using wood with a moisture content above 14% isnt recommended because it may have detrimental long-term effects on the construction. I had a water leak under my crawl space which has 3 inches of foam insulation applied to the underside of the sub floor. In contrast, Las Vegas in the drier Southwest has much lower EMC percentages than most other U.S. cities. I have seen that 13.5% is high for furniture and you should aim below 12%. This chart highlights the ideal levels of moisture in wood at various temperatures and relative humidity (RH) levels: In this chart, you can see a small highlighted section. Leicester, NC 28748 Home Moisture Meters Acceptable Moisture Levels in Wood Knowing the Moisture Content. As stated, fungal spores are beneath the home because they are in the air we breathe-the same air that gets circulated beneath the home. Knowing were all the piers are, I can stand on top and feel a small hump in the floors. SE, Huntsville, AL 35802. Here is a link to a moisture meter I recommend: https://www.wagnermeters.com/shop/orion-910-deep/. Standards and tolerances guide | Queensland Building and Construction Wagner has a free app called WoodH2O to help you determine the proper moisture levels based on consistent humidity and temperature. The interior was 3/4 BW the tables dimensions were 40x 70 . Damn those shop classes I didnt take. After my inspection I wrote the following report: As per your request, I visited the subject residence today to evaluate mold or fungus growth on the floor joists. Great article, thanks for the info. board will move twice as much as a 4-in. You must be careful with a thick slab once you cut it. He added that plastic sheet ground covering that his company laid over my crawl space had been moved in spots and that I no longer had full coverage. Wide-spread and often extensive moisture damage occurs in residences across the state of South Carolina and elsewhere in the Southeast due to the regions warm, humid climate. The typical moisture content for hardwoods that will be indoors is 6-9 percent. I suspect the moisture was the culprit? The levels were between 20 and 23%. I never obtained a moisture reading above 16%. Houses with timber-framed floors can be at risk of having poor underfloor ventilation. The moisture content of wooden substructure members is routinely being disclosed in the closing process of real estate transactions. A floor joist is a horizontal beam, usually made of wood, that is used to support and enclose the flooring above a foundation. 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. Over a year ago, I re-shim all the piers with metal shims. What is an acceptable crawl space wood moisture content? The ASTM D4442 standard determines the accuracy of wood moisture meters. When determining the acceptable moisture levels in wood flooring before installation, the NWFA states that the flooring professional should establish a baseline for acclimation. It will be there for a few months before I begin working on it. 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%. Floor Joist Sizing and Span In Residential Construction - Weekend Builds As it dries, you should expect slight changes in width and length. Take the readings in at least 20 spots per 1,000 square feet of flooring and average the results. Dryer wood produces more resistance than wetter wood. Such readings should alert the homeowner to look for a source of excess moisture. Post and beam constructions don't have to be kiln-dried but should be air-dried. Well, tile, bricks, and stones are known to have a low water-holding capacity and therefore should be dry. I read your article and really like it. 1. 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. The other thing to consider is examining how water is entering your crawl space. The purpose of the vapor barrier is to keep moisture away from materials that expand and contract. Working with some slabs of spruce. Moisture content (MC) in raw slabs can take additional time to reach its Equilibrium Moisture Content. board will move 3 times the amount as a 4-in. The door is NE facing and protected from direct Sun light and rain by a porch roof. If the middle is wet, you may experience cracking/splitting if dried too fast. The plumbing was improperly installed with the wrong cement to fit the pipes and could have been leaking from anywhere between 5-29 years while absorbing into the ground. Any moisture content measured higher than that might result in movement, such as warping and twisting, once it dries. I have used spar urethane as a finish on a few other 12 to 18 MC (semi-wet) log projects that turned out wonderfully. I found your moisture levels column through a search for good wood for low humidity. It will continue to absorb and release moisture until it comes into balance with the surrounding air. The flooring pieces should be removed from the packaging to allow the ambient conditions to equalize the wood. Will the reading be accurate? Furniture grade wood is typically dried to a target of 6%-9%. Should I remove more foam to be sure. Many of our customers are successfully using our hand held moisture meters on engineered flooring. 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. When questioned, he said because Room is under 200 sq feet it is not a problem. Which Orion moisture meter model would you suggest for my application? The difference is the moisture meters measurement error. Required fields are marked *. Does coating wood with oil stabilize the moisture content in wood? Now the fungus goes dormant. Great info! Were so sorry for the inconvenience. Toilet overflowed and moisture meter is reading 30% in worst area. Softwoods, such as spruce, can have more moisture. 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. Fresh cut trees can have a wood moisture content over 200%, while completely dried wood will have a wood moisture content of 0%. The company they hired measured 47% in the wood and declares that this must be ripped out and replaced. 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. 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? Hi Moisture Experts, My house is 25 years old located in Oregon City OR (near Portland). 9.1.5 Floors - NHBC Standards 2023 NHBC Standards 2023 If the moisture content of the product is well outside the range of optimal MC, the wood flooring should not be accepted because it will lead to shrinkage, bowing, cupping, and other physical problems. Crawl Space Inspections: Once a Year Keeps the Contractors Away! PDF Specification for Solid Timber Flooring Installation, Sanding - ATFA My house is 24 years old. He asked if I could double-check the findings of another home inspection company that requested expert advice on some mold/fungus they found in the crawl space of the home. So, when looking at the relative humidity of the space, spaces left above 70% RH for extended periods will also promote mold growth. . https://www.wagnermeters.com/wood-moisture-meters/. It is impossible for me to tell you what the percentage of furniture should be, but if you know the EMC in the area it will be kept, you can check the MC continuously until you reach its EMC. As the humidity decreases, the MC decreases, causing the wood to shrink. I-joists are strong, lightweight, "I" shaped engineered wood structural members that meet demanding performance standards. Typical moisture content for furniture in a home is 6-9%. It seems to me the supplier is drying the Teak to 14% because that is what is needed in Indonesia. If the MC of plywood is above 20%, can it be redried in a kiln or would that harm the glue? Wood moisture content is always varying. If youre wondering how wood can have a 200% moisture content, heres how that works. This would depend on the expectations of the person receiving the product in India, how large of diameter the logs are, and some average estimate of what the conditions would be inside the container during the 55 days. How to Level a Floor - Lowes Chris. However, and unless otherwise permitted by a flooring product manufacturer, the following maximum moisture emission levels over a 24 hour period are permissible for the following floor coverings types: Should you check moisture levels on a trailor floor on a massive rainy day? board, and a 12-in. These include warping, cracking, buckling, diminished wood strength, corrosion of fasteners, and even fungal growth. They are now saying that they will replace whatever boards are bad and resand and finish the floors, however Im concerned that there is an underlying issue that will resurface here? 2nd question, will lacquer on surface of flooring affect the reading. I have about 3,000 sqft on my first floor and this was relatively consistent throughout. somewhere. Most interior wood is in this range. These are the "safest" conditions for most types of woodbetween 60 and 80 degrees Fahrenheit and 30% to 50% RH. What are acceptable ranges of moisture for composite materials like MDF and Plywood, for indoor furniture use? The National Wood Flooring Association (NWFA) has a chart that indicates the moisture content of wood at any given combination of temperature and humidity. Under the floor. Larry: I recently had my annual termite inspection. 2. What are Acceptable Moisture Levels in Wood? It does the same for wood, and is especially hard on softwoods, such as pine or fir. 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. If a wooden sample has moisture content range of 2-6% only and if it has moisture content of 9 or 10% then what does this mean?? We just had a hydrometer installed in the crawlspace and it is reading 38% as of today. Down pour of rain onto underlayment of attached garage. Hello Larry I am from Bangladesh. (864) 506-4701, South Carolina Residential Construction Standards, http://www.rlcengineering.com/wp-content/uploads/2019/04/RLC-Engineering-1.png. The NWFA recommends testing wood subfloor moisture in at least 20 locations per 1,000 sq. Mold growth can be limited if the MC of wood can be kept below 20%. Everyone who works with wood needs to understand how wood interacts with moisture in the environment. In other words, the water weighs more than the wood fibers. Am i looking at mold if i dont rip the floor out? I cant speak for other pinless meters but our Wagner meters are not sensitive to the temperatures you indicated. Do these levels seen appropriate considering the recent rainfall. How to Level a Floor: 8 Important Things to Know Before You DIY - Bob Vila Floor levels and clearances | BRANZ Weathertight Thanks for the the information, very detailed and useful. I have seen home built in the dead of winter, covered in snow, and still dry out enough for a successful home build. The builder's warranty representative came out and measured the moisture levels with a moisture meter. The manufacturer of the oil-based poly should have a specification on the maximum allowable moisture content of the wood. Acclimation is the process for conditioning the moisture content of wood flooring to the environment where it will be installed. Failure to do this will result in warping, cracking, and other problems after the construction of the wood product. If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity. If your subfloor is a wood product, make sure the reading is less than 20% on the moisture meter. So if I understood the article right and not sure that I did. Thats why I think the wood is either not dried to 14%, or it has picked up too much humidity after drying. 78 0 obj
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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. or finally the product will be placed where. 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 dont understand how the bottom beam looks like swiss cheese from all the holes ive drilled and has had a commercial blower on it for days yet the number is still high despite there being no visible water to keep the wood wet. A consistent humidity level of 40 percent will require wood to be about 8 percent moisture content. You will want closer to 6% in the drier climates and 9% MC for the more humid climates. We found out that RH at the final location was under 20%. Since Im drying them outside, being in AK I would like to work with them if possible before the long moist winter. A Brief Guide to Mold, Moisture and Your Home | US EPA Be on the lookout for flooring failures such as swelling, buckling, cupping, etc. Notches at the end of the joist should be no deeper than 1/4 the depth. I also applied Boracare (boron) that has stopped minor beetle damage. 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. Actually floors account for 15% of building heat loss depending on construction. Notice that the EMC of the in-use location is the same as the MC: So, using this chart, we know that in an area of the country where the RH inside a home or office is anywhere from 26-32%, both the EMC of the in-use location and the wood moisture content kept in that location will be 6%. Production, storage, delivery and construction and in-use conditions that will prevent exposure to external or internal moisture or conditions that would allow the moisture content to exceed 18% at any time: Untreated Douglas fir: Framing in a low-risk building and meeting the requirements of B2/AS1 paragraph 3.2.2.2: Where there is a risk of . A Homeowner's Guide to Floor Underlayments | Hunker Different joinery (currently using pocket holes)? Waterproof membrane . We had boards that were also cracking/splitting and other places where small pinholes were showing up. Cheers, Howard Pruden in Edmonton, Alberta where its cold and dry. Again, the correct moisture content will depend on the surrounding conditions. 3. Yes, it is possible to have a moisture content reading of 99.9%. Its more important to understand that the wood is kiln-dried down to a certain bell-shaped range of MCs. So, to sum up, Moisture in crawlspaces is bad. Floors-1/2" in 12' or 3/16" in 4'. This will drastically speed up the drying process. WMC of framing members in a crawl space will usually be lowest in late winter and highest in late summer. Currently the RH is 76%, the residence RH will be set at around 35%. These mold spores land on the wet wood and take root. Since water conducts electricity and wood doesnt, the dryness of the wood can be determined by the amount of resistance to an electrical current. our question is do we need to replace the floor to avoid fungal problems? Condensation present on the . That doesnt make much sense to me. Because ventilated crawl spaces throughout the Southeast United States allow high humidity and fungus spores to enter the enclosed space beneath the home. 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.