Most are reading are between 13-15%. Most interior wood is in this range. How best to handle moisture inside concrete block basement walls? A floor joist is a horizontal beam, usually made of wood, that is used to support and enclose the flooring above a foundation. Crawl Space Moisture and Hardwood Flooring - Stover's Liquidation Walking on Joists Before all accessories and floor decking are installed, I-joists are unstable and can roll over if walked on, leading to injuries. Perhaps try to seal the vapor barrier better around the piers. 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. The pins are pressed into the wood to obtain a reading. 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. I am not sure if this is pressure treated wood given its an exterior wall and if that affects what these numbers are. 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. Any suggestions to this being possible to correct? However, the wood species and the thickness or size of the wood may also factor in. I did not find any information on Matumi. Back to top. If this is confusing, dont worry. Will the reading be accurate? Im in Milwaukee, wi if that matters. The National Wood Flooring Association (NWFA) has specific installation guidelines for wood flooring and how they relate to moisture content. . Thanks for the question. : Mold & Fungus In the Crawlspace. One of his own service guys said foundation caps needed to be replaced. If the wood would really arrive with a MC of 14%, we would not have any problems. Longer pins with insulated shafts are designed for the purpose. hellow! The crawl space must be a minimum of 18" to the bottom of the floor joists, and the soil in the crawl space covered with a heavy duty plastic moisture barrier, and sealed at the seams. Wood exposed to air with a RH of about 90% will reach a Wood Moisture Content of about 20%. Moisture contents in wood floor joists in houses with moisture problems are exceeding the 20% maximum level for air dried lumber. Your table may have been a little too high in moisture, hence the crack as it dried slightly in the drier environment. I have 1 1/2 thick cherry boards that I had milled from a tree in my yard last fall. They many times cite the need for further evaluations by what they call other so called experts. Wood Rot in Crawl Spaces: Whats That Smell in My House. 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%. Well, tile, bricks, and stones are known to have a low water-holding capacity and therefore should be dry. A moisture content of less than 20% indicates that your joists and beams do not have the necessary moisture content for mold or fungus to survive. This is based on a chart in Wood Handbook: Wood as an Engineering Material. I have removed the 1 3/4 edge and resawn to take out the splinter (1/4) re bicuited . In general, all wood products will swell with an increase in moisture content and shrink with a decrease in moisture content. we are presently constructing a new timber frame residence on ocean front in BC, Canada. I recommend one of our Orion models: https://www.wagnermeters.com/moisture-meters/. This document describes the meaning and use of readings from a wood moisture meter. Most of it will dissipate. Leicester, NC 28748 Oiling the surface does not control the moisture in the wood. How To Control Crawl Space Moisture + Humidity What is the acceptable moisture level for plywood? (He didnt cite a figure.) If the water leak was bad enough, dry rot can occur causing possible structural integrity issues. The size of the lumber used for floor joists is the single greatest determining factor in terms of how far a joist can span. All Rights Reserved. Reaching these moisture content levels does not mean mold growth or corrosion . if not, can you tell me why? Learn the Basics of Floor Joist Spans - The Spruce Since wood is hygroscopic, it loses or gains moisture depending on the relative humidity of the surrounding air. Thank you for the helpful article. 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. Obviously, the ambient conditions within which the wood or paper is present can alter the MC% of the wood or paper. Utilize the chart on following page to record the environmental readings at the time of installation. Should it be less? I-joists are strong, lightweight, "I" shaped engineered wood structural members that meet demanding performance standards. Using wood with a moisture content above 14% isnt recommended because it may have detrimental long-term effects on the construction. . I read your article and really like it. The process is time-consuming but produces accurate results if followed correctly. As lumber dries, it may split, cup and warp. We just had a hydrometer installed in the crawlspace and it is reading 38% as of today. Both slab-on-ground and suspended concrete floors for wet areas: are deemed impervious when steel trowel finished or polished. Kiln-dried wood usually shows a moisture reading of 10% on the outside and then 25% on the inside. 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? The builder's warranty representative came out and measured the moisture levels with a moisture meter. Moisture content in floor systems - Structural Inspections - InterNACHI During the increased average temperatures of spring and summer, timber moisture content reduces to more acceptable levels. I found your moisture levels column through a search for good wood for low humidity. It is best to obtain a wood moisture content that will match the environment. Floor Joist Calculator Free Webinar The What, Why, and How of Wood Moisture Testing. 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. Subfloor material such as plywood or OSB should measure between 10 and 14% moisture content. Outdoor temp is 99*F. Is this normal? Different wood? in other hardwood areas that wasnt close to the water, was measuring about 16-19%. 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. I am building a farm style dining table with pecan 2 thick X 8-0 long boards. Pinless moisture meters are even easier to use. The air vents stay closed year round. Thank you so much for your time and expertise. The boards should be no wider than 6 inches and installed on a 45-degree angle. 3. Softwoods, such as spruce, can have more moisture. 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. Once the wood samples weight stops changing, its weight is compared to what it was before the drying process began. 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. And it's important to keep in mind that a glued-up panel behaves basically as one wide piece of lumber. The acceptable moisture levels of wood and lumber are in the range of 6% to 8% for interior and 9% to 14% for exterior wood or for building envelope components within constructed assemblies. You can use our free APP called WoodH2O to help you decide on the best moisture content. 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. Guidance on exposure limits | BRANZ Or perhaps I should advise them to buy Wagner meters, for better accuracy ;-). (Itd effectively seal the cavity under the vanity, so once the trim is back on, i dont think itll dry out much more.) Top 5 Causes of Cracks in Brick Veneer Homes. 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. Thanks!!! Not using the correct procedure. The chart below will clear things up. We have a free app called WoodH2O for Android or iPhone. To make sure the wood is properly dried, he always uses a moisture meter before working with it. Great info! We found out that RH at the final location was under 20%. Keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly. Normal moisture content of wood ranges from 7% to 19%. Floor Joist Sizing and Span In Residential Construction - Weekend Builds Working with some slabs of spruce. This week, I notice the next pier on the same beam is starting to push up, warping the floor. I want to use it to build a table and will be moving it to the location where I will work on it shortly. Maximum Moisture Content Of Concrete This is a nominal value most product manufacturers specify when concrete is dry enough to allow their product to lay down on it. 10? Im not sure I can really answer this question. Acclimation is the process for conditioning the moisture content of wood flooring to the environment where it will be installed. 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. 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? Not only did the aggressive notching doom this joist, it affected the structural integrity of the floor system above. I really need to know as I am getting so many different opinions Thanks. Your reading of 12.5% tells me it is workable. I strongly recommend using a moisture meter, along with a thermo-hygrometer, or even a smart logger before you start building, to ensure the wood is at an optimal moisture content in an environment that has an acceptable relative humidity and temperature range. Which Orion moisture meter model would you suggest for my application? If the middle is wet, you may experience cracking/splitting if dried too fast. Moisture Content of Wood | Everything You Need to Know - Reliance Timber This must be done before attempting to dry out the wood. I hope that helps. Summers are hot and dry while winters can be cool. Sorry, that time of year. I get some water seepage through an exterior wall at basement floor level as a result of heavy rain. 1 4 Concrete floors. A dry reading will be 16% MC (Moisture Content) or below. In the Midwest, the EMC of wood or lumber in Des Moines, Iowa, ranges from 12.4% to 14.9%. However, many building materials may have been dried down to about 15% moisture content. Waterproof membrane . I had a quick looked around the crawl space and didnt notice any structure damage. If decay or WMC readings over 28% are present, find and fix the sources of liquid water quickly. There will most likely be some shrinkage, so if possible, choose the clearest boards possible to lessen the possibility of any major cracking. Too dry and you get chipping out of the wood. I cant speak for the home inspector who has raised concerns, or what his experience level is, but I can assure you that the floor joists beneath this home are no different than 90% of the floor joists I have inspected over the past three decades. First, test the moisture level of the subfloor. What % does it have to get down to before it would be usable to make a table top ? Wood in buildings usually has a wood moisture content of 5% to 15%. Any suggestions .thanks. This type of floor-leveling is DIY-friendly and costs approximately $1.50 per square foot when applied 1/8-inch thick. 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. Structural flooring for laying direct to joists or battens is a minimum of 19mm thick. Screwed 2x4s parallel into the joists as added support. The excess moisture source should be corrected immediately, and monitored until the WMC returns to the 12-16 range. Ive been following your in depth blog on moisture meters for around 1 year now. 800-347-7260 Fax. 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. Wood Moisture Content is the weight of water in a piece of wood expressed as a percentage of oven dry weight of wood. 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. Truss Uplift: Who Would Have Ever Thunk It? 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. Hello, Paul here. I so appreciate your treatise on this issue. Continue reading MC in the home. What Are Safe Moisture Levels for Hardwood Floors? - Delmhorst h_k0 r ?c|@+wpF=M^r? ( BzPxgA9P{j]s 3r\WQu\@U.Jy'h{>dccy. i did not waterproof the outside of the curb (kerdi), so the wood got wet. %PDF-1.2 % So the question is are those burrs or fuzzing on the edges?, Wed love to have you give us a call to discuss which moisture meter is best for you. Be on the lookout for flooring failures such as swelling, buckling, cupping, etc. The three main sources of moisture: Condensation, Foundation wall transfer, and leaks. summary Wood must always be allowed to acclimate or come into balance with the RH of the end-use location. With a degree in Computer Systems, Larry is involved in both hardware and software development of wood moisture measurement solutions. You should be able to specify a lower moisture content. Yes, our moisture meters read MDF. A high reading in one area indicates a problem that must be corrected. . In your blog I read that furniture for outdoor is dried to a MC between 9 and 14%. Here is a link to our website for more information: https://www.wagnermeters.com/shop/orion-950-smart/. We really cant overstress the importance of taking plenty of moisture readings. The acceptable wood moisture content normally ranges from 6% to 8% for woodworkers who build cabinets, fine furniture, musical instruments, dishes, toys, decorative art, boat restoration, or various other wood products. PDF Subsurface Tolerances and Floor Flatness Requirements A Case for