Brilliant article. 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. Box 1437 Why and how can I say this? At this home, cool objects include the air conditioning ductwork, the ground and the overlying wood floor system, which is exposed to very cool temperatures due to air conditioning duct leakage. 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. Now the fungus goes dormant. Furniture maker Lonnie Bird weighs in, I dont want the wood to shrink after I use it because the wood will warp or split.. our question is do we need to replace the floor to avoid fungal problems? With the WoodH2O-app I could deduct the EMC for The Netherlands would be between 15 and 16. Readings can be elevated if there is a stud directly behind the sheetrock. Your table may have been a little too high in moisture, hence the crack as it dried slightly in the drier environment. There is only so much moisture a piece of wood can give up, over time, before a failure occurs. We had boards that were also cracking/splitting and other places where small pinholes were showing up. Congratulations on your new furniture. Therefore, in order to avoid post-construction problems, a woodworker building a cabinet for this particular interior environment would need to dry his wood to a moisture content of 8- 9% beforehand and then keep it that dry during the construction process. Good luck. Its always a good idea to check with the manufacturer of the finish also. The water eventually came out a electric outlet located three inches off the floor. Hi Larry, thanks for the great knowledge sharing. The inspector said his meter reading taken from my basement on subflooring/joists/framing was too high. within two percentage points of the EMC where the wood is going to be used. Question for the expert: i recently replaced a toilet that had a leaky wax ring. A floor joist is a horizontal beam, usually made of wood, that is used to support and enclose the flooring above a foundation. I dialed the 800 number for Wagner meters and all I got was two sales pitches for a Life alert type device. They delivered the wood one day, and began to stain and install it over the next two days, finishing on the 6th day. They need to carry a moisture meter with them under houses and probe the floor joists to measure wood moisture content. 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). Were in northern Indiana, humid summers long cold winters. (864) 506-4701, South Carolina Residential Construction Standards, http://www.rlcengineering.com/wp-content/uploads/2019/04/RLC-Engineering-1.png. Thanks. Hope this helps. When determining the acceptable moisture levels in wood flooring before installation, the NWFA states that the flooring professional should establish a baseline for acclimation. A termite repair company (also licensed contractors) told me that I needed to replace the planks on my second story deck. Instead of addressing the plumbing and damaged wood, they installed a dehumidifier in 2015. Your help for resolving this issue would be highly appreciated . 1= z@ If you need further clarification http://www.nwfa.org is an excellent source. 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. It gains or loses water moisture as the relative humidity (RH) of the surrounding air changes. how do I determine the mc standard for this material, is it the same as wood or has its own specifications, 2. Obviously, the ambient conditions within which the wood or paper is present can alter the MC% of the wood or paper. Brick Veneer Homes: Are They Really Worth the Headache? An MC in this range, therefore, is considered sufficiently dry for exterior in-service wood. I had a water leak under my crawl space which has 3 inches of foam insulation applied to the underside of the sub floor. The floors have started cupping across the entire area with more in some parts. Hi and good day , I would like to find out what r the right temperature readings for workable wood slabs in South Africa specially Matumi wood slabs. I checked it with my new moisture meter and had a reading of between 8-13.5%. Im down to ~13-19% MC near floor level, based on a cheapo moisture meters readings. Typical moisture content for furniture in a home is 6-9%. It will continue to absorb and release moisture until it comes into balance with the surrounding air. Again, the correct moisture content will depend on the surrounding conditions. 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. There will be statistical outliers on both the low and the high end and youll want to catch these by using a quality moisture meter. This pin-type moisture meter is one of Delmhorst's most popular models. One of the beauties of spar is that it allows the wood to move quite a bit, while still retaining good adhesion. Using a moisture meter before painting can help you determine the moisture content of the wood. This means the weight of the water exceeds the weight of the wood by itself. 1 4 Why Do So Many Homes Have Cracks in Their Brick Veneer? Joists that sit below end matched joints must be at least 35mm thick. For most areas of the United States, acceptable moisture levels of wood and lumber can be in the range of 9% to 14% for exterior wood or for building envelope components within constructed assemblies. They are currently nearing equilibrium (around 12 MC) and are stored within the house. Do these levels seen appropriate considering the recent rainfall. 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. The electrical current will then move from pin to pin and measure the resistance encountered. The excess moisture source should be corrected if found. Its not growing or feeding on the wood. I am based in The Netherlands. You can determine the correct percent moisture content by using our free app called WoodH2O. In this case, what Built in # that I can use to measure flooring. Surface molds may develop. 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. I am not aware of a standard moisture content for packaging food or any other product. Reaching these moisture content levels does not mean mold growth or corrosion . 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%. Such readings should alert the homeowner to look for a source of excess moisture. First of all, it's normal for a below-grade concrete block wall in contact with the soil to have a high moisture content. That doesnt make much sense to me. or finally the product will be placed where. Now would the pine be okay to use as a top cover piece to an radiator cover? Thanks for the question. Thank you. We are very arid where the tops were built so I figured the tables would be just fine knowing that it is arid where they were goingbut that doesnt seem to be the case. Wood exposed to air with a RH of about 90% will reach a Wood Moisture Content of about 20%. Too dry and you get chipping out of the wood. Waterproof membrane . Please dont pay for a Borate spray unless the buyer wants to pay for it. 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. Wood Moisture Content (WMC) is often used as an indicator of decay problems in houses. These home inspectors are insecure and inexperienced. Keep monitoring it. Utilize the chart on following page to record the environmental readings at the time of installation. Indoor humidity is around 50%, indoor temps around 70 degrees. I get some water seepage through an exterior wall at basement floor level as a result of heavy rain. When questioned, he said because Room is under 200 sq feet it is not a problem. 541-679-2612 www.Roseburg.com. I-joists are comprised of top and bottom flanges, which resist bending, united with webs, which provide outstanding shear resistance. Studies have shown, however, that mold growth can occur on wood at moisture content levels above 15 to 18 percent, and corrosion of metal fasteners in treated wood can occur when moisture content exceeds 18 to 20 percent. Call JADE today for a crawlspace inspection and we can give you definitive answers to your crawl space problems! 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. Request Answer. Keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly. My house is 24 years old. 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? The joists can be longer or shorter as required by space and size, and are typically spaced at either 450mm or 600mm apart. In an air conditioned house the wood floor. Simply put, the post offers some useful information. During the summer months in the northeast region, wood subfloors and floor joists often measure 19. Because wood shrinks and warps as it dries, woodworkers want it to be pre-shrunk before they use it. Why You Should Use Relative Humidity (RH) Testing, Flooring, Millwork, Furniture & Cabinet Manufacturers, How to Choose a Moisture Measurement System for Your Sawmill Buying Guide, Acceptable Moisture Levels in Wood Knowing the Moisture Content, Free Download 5 Ways Pinless Moisture Meters Save You Time and Money. Wood moisture content between 0% and about 28% is dependent upon the relative humidity (RH) of the air. The moisture content overall is almost always below 20%. A company sealed off the foundation vents and removed all the insulation from the crawlspace with the humidifier mitigating the moisture from the leaks. If the MC of plywood is above 20%, can it be redried in a kiln or would that harm the glue? Perhaps there is something different about the East and West walls. Please provide us with regular updates. . I have Suar wood from Indonesia and want use to indoor furniture, how range the Moisture Content allowance for this wood. Sometimes moving the air around is enough to remove moisture and dry surfaces. I have built two table tops (douglas fir) that have both suffered major cracking in their final location. Foundation Underpinning Repair: Unnecessary? Working with some slabs of spruce. Hope that helps. The difference between the wood subfloor and the hardwood flooring shouldn't exceed 4% for solid strip hardwood . One note is that we did have some fungus growth in our crawlspace during the construction phase prior to the crawlspace being sealed and had the contractor come and spray and clean the floor joists and subflooring where applicable. ie SW=Starting weight, TW=Target weight, using T%=Target percentage My calculation ( T% X SW = TW). board will move 3 times the amount as a 4-in. The chart below will clear things up. 78 0 obj <>stream The front of the . The home inspectors working for fees today seem to have one primary motive in mind: to cover their liabilities. Did the Contractor mention anything about the structural strength of the joists? Thanks for the the information, very detailed and useful. Damn those shop classes I didnt take. primer, the moisture vapor transmissions rate (MVtr) from the substrate should not be in excess of 5 lbs. Wiki User. Ive been following your in depth blog on moisture meters for around 1 year now. The floor installer put the floors down without allowing the boards to acclimate. A subfloor needs to be clean, dry, level and structurally sound. 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. Condensation on the inside of a windowpane. "Mold requires moisture to survive, so protecting lumber and wood structures from moisture will prevent mold growth. Currently reading a 12.5%. Here is a link to our new line of meters: https://www.wagnermeters.com/moisture-meters/. board, and a 12-in. 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%. moisture meter testing a floor joist In this image we measure a reading of 37% in this floor joist. Its still there and causing stains and scaring inexperienced home inspectors who frighten buyers, but its dormant. A mold or mildew odor or appearance on surfaces. But this wetness is only surficial. You should be able to specify a lower moisture content. Here current humidity is 76%. Once wood is dried below about 28% WMC, water is not available to support decay, unless the wood is exposed to liquid water. Any input would be most appreciated. Mobeen, If a wooden sample gains moisture, then the sample will increase in size. 15% is too high, at least for hardwoods. This only occurs when wood changes moisture content below the fibre saturation point. For joists where the rot infestation has been thoroughly dealt with: it is acceptable to leave the joist as it is. Perhaps better drainage around your house will do the trick or treat. For example, from 25% to 45% or from 45% to 65%. For wide-width solid flooring (3 or wider), there should be no more than a 2% difference in moisture content between properly acclimated wood flooring and subflooring materials. My thought is maybe to get one of your meter for greater accuracy? The thickness of flooring joists themselves will be determined by what's going on top of them. So what do you think is the ideal moisture% I should dry them to before rotary polishing them? What wood do you recommend that does not have a high oil/water content? Wood is a hygroscopic material that contains water, even after it is cut from a tree. Engineering & Inspection Services, Licensed PE - Alabama & Tennessee, JADE Engineering & Inspection | 5405 Whitesburg Dr. Wonder if they are trying to cover themselves. After reading your article and following comments, my question is : How much does the finish of a wood project for indoor use affect the moisture content? Live in Tn. The wood joists are not soaked wet, its just a light film of moisture on the wood members. You can use a dehumidifier when you need your crawl space drier, but it's essential to maintain proper moisture levels as much as possible. Treatment levels for timber and timber-based materials used under tiles in wet areas where the waterproofing membrane cannot easily be inspected or maintained should be: H1.2 for timber floor joists and wall framing around showers; H3 (CCA treated) for plywood. One type of wood moisture meter. Thank you. i am baffled. Here is a link to our website for more information: https://www.wagnermeters.com/shop/orion-950-smart/. It seems to me the supplier is drying the Teak to 14% because that is what is needed in Indonesia. The engineered wood floor appears ok. Sagging or Uneven Floors Solutions. These are typical readings for exterior wood. I suggested replacing my dehumidifier (Sears brand, bucket collection) which has been inoperable this past year. 12.5% is gettin there but not quite to the 6-9% mentioned in the article. If humidity levels in the crawlspace with all these measures taken place is above 60% the joist and the subfloor will have a high MC reading. of water/day/1000 sq. For a wooden subfloor you will need to use a 2-pronged moisture meter. What are acceptable ranges of moisture for composite materials like MDF and Plywood, for indoor furniture use? In their warehouse, and perhaps partly also in the container. Be sure to acclimate the wood to desired EMC of the interior environment before you use it. If so, then you'll want to know. this is an interesting read I landed upon as I was searching for MC in wood items. This week, I notice the next pier on the same beam is starting to push up, warping the floor. (EMC) than other pieces of wood, depending on its location. I found your moisture levels column through a search for good wood for low humidity. with the spring thaw, i was one of the lucky ones that got water in my basement. Many thanks for your advice, really appreciate it! Thanks! Hello! Why and how can I say this? 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. I live on the fl coast so what should the moisture level be? SE, Huntsville, AL 35802. Fungus loves wet wood. 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. Replaced the subfloor, which is . I have 1 1/2 thick cherry boards that I had milled from a tree in my yard last fall. You may be picking up something behind the sheetrock. I wanted to talk to someone at Wagner about moisture guages and is there a dealer near Chattanooga, TN. The problem is some of the water made its way under the basmenet bathroom floor which is dricor with electric heating wire on top, then tiles, and unfortunately it looks like some of the dricor wood got wet as well! for a mere $4900. If the leaks have damaged the sub floor or joists, call a licensed general contractor for repair. Finally the question I have is I-used your Wood H2O app and the humidity here (outside) is 55% and the temperature is near 70 (inside)am I correct that 10% is what Is the acceptable moisture of the wood should be for furniture building? Can I a cut them first, then glue them once they are dryer? How Timber Reacts To Moisture. Unless something is so out of whack shimming in back of the sheetrock won't suffice it's OK here. WagnerMeters 1.93K subscribers 3.2K views 1 year ago Hardwood Flooring - Tips & Problems Do you work with wood? Be notified when an answer is posted. I had several of the varnished decorative hardwood laminated ply panels replaced in the lounge on an air conditioned luxury yacht. You can use our free APP called WoodH2O to help you decide on the best moisture content. I installed a sump pump and 6 mil vapor barrier, but the barrier is not sealed around piers and the ground is moist under the barrier all year. Whats the Difference Between a Home Inspection and an Engineering Inspection? 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?