17 and the flooring is at 6 to 7. ft., and averaging the results. Floor joists transfer loads to the vertical beams of the house. I am shipping teakwood furniture from Indonesia to California. So, is it really this wet or is our meter over-reading? 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. 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. A consistent humidity level of 40 percent will require wood to be about 8 percent moisture content. You wrote that 15% humidity may induce mold? 2nd question, will lacquer on surface of flooring affect the reading. When wood is subjected to an environment that is higher in humidity, it will swell or expand. 7 Common I-Joist Installation Mistakesand How to Avoid Them If the water leak was bad enough, dry rot can occur causing possible structural integrity issues. The cause that may produce this will be discussed in the section "Biodeteration of flood". This is more likely to occur to occur in lower-grade boards, where knots and uneven grains are already present. Perhaps better drainage around your house will do the trick or treat. Replacing Subfloor: What You Should Know | Hunker Im planning on using some of it to build a new front door for the house and was wondering what MC I should be shooting for. Dryer wood produces more resistance than wetter wood. You will want closer to 6% in the drier climates and 9% MC for the more humid climates. Stopping the moisture is much cheaper and easier than repairing the structure. Post and beam constructions don't have to be kiln-dried but should be air-dried. Yes, our moisture meters read MDF. I live in upstate South Carolina. As it dries, you should expect slight changes in width and length. I appreciate you sharing this important information with us at this time. Both times, the tables were flawless, but after 2-3 weeks in their new home both table tops had major crack issues. 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). And it's important to keep in mind that a glued-up panel behaves basically as one wide piece of lumber. A Brick Veneer Crack Tragedy: A True Story, Spraying for Mold on Floor Joists: Pest Control. wood using pins while the MDF uses pinless? We found out that RH at the final location was under 20%. Thank you so much for your time and expertise. The interior wood moisture level should be 12% or lower before painting. Such readings should alert the homeowner to look for a source of excess moisture. I live in Charlotte, NC. If your subfloor is a wood product, make sure the reading is less than 20% on the moisture meter. In the Midwest, the EMC of wood or lumber in Des Moines, Iowa, ranges from 12.4% to 14.9%. Thank you, In wood products manufacturing, 6-8% is pretty much the norm, at least in North America. All that needs to be done at this home is to close-up the foundation vents during every air conditioning season and make sure the ground cover vapor barrier is spread completely over the underlying ground surface. The next question is almost the same as before, if we have various kinds of wood, such as March wood, mango wood, pine. 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. My main concern here is that the flooring didnt have enough time to acclimate to the surrounding conditions. Remove Moisture From The Air - If your crawl space has a lot of ventilation, you should be able to set up a large fan in the opening of the crawl space and leave it to run for 10 to 12 hours. Understanding Moisture Content and Wood Movement It seems to me the supplier is drying the Teak to 14% because that is what is needed in Indonesia. Here is a link to our moisture meters, thermo-hygrometer, and Smart Logger. PDF Solid Wood Flooring Installation - Mullican Flooring Normal moisture content of wood ranges from 7% to 19%. Based on common guidelines or recommendations, the acceptable moisture levels for wood are as follows: Keep in mind that a woods acceptable moisture level will depend primarily on how it will be finally used and the average RH where it will be finally used. "R. So chart would indicate around 9%. The solution seems to be drying the wood longer & bettter, to a lower measured MC. 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. . There are joists that display splitting. They need to carry a moisture meter with them under houses and probe the floor joists to measure wood moisture content. Had fans and dehumidifer running for 17 days starting 2 days after leak. There is no balancing layer on the reverse of the panels which might obstrust breathing of the panel. (He didnt cite a figure.) It is not uncommon for wood to expand or contract as much as a 1/8 per foot of width, so maintaining a stable environment is important. 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. Thanks Mark, The EMC outside and the wood should be the same. 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? 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. Again, the correct moisture content will depend on the surrounding conditions. A mold or mildew odor or appearance on surfaces. How To Control Crawl Space Moisture + Humidity we are getting hardwoods from our Uk Suppliers and accoya coming in at 2% and once we use the timber we are reading 0% we have tested the reader and its accurate even joinery grade sapele wood and Tulip wood coming in at 0% we cover these in 3 coats of sikkens paint and sometimes we get jobs where we are having to go back as our joinery is moving and we are guessing its because of these moisture levels and had never checked previously. A wood moisture content of 47% is too high. The water wasnt properly dried and organic growth was discovered by previous owner. It is also possible to have moisture content readings over 100%. Its not growing or feeding on the wood. 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 . In general, all wood products will swell with an increase in moisture content and shrink with a decrease in moisture content. When determining the acceptable moisture levels in wood flooring before installation, the NWFA states that the flooring professional should establish a baseline for acclimation. Congratulations on your new furniture. Hi Moisture Experts, My house is 25 years old located in Oregon City OR (near Portland). Floors-1/2" in 12' or 3/16" in 4'. Any input would be most appreciated. Hi Davetta, Youll need to contact a local mold inspection company that is certified. PDF Research Findings on Moisture Management - LSU AgCenter 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. Step 1: Check the Floor. Required fields are marked *. I have a question, I have moisture in the crawl space, we insulated the crawl with closed cell, cannot get the osb subfloor below. Thank you for the helpful article. I suspect the screws may be skewing the measurements. Floor joists are generally 6, 8, 10, or 12 inches in width, with 8 or 10 inches as the most common sizes. Question: Just to make sure that you get accurate moisture measurements, has your moisture meter been checked for calibration? We are shipping some acacia chopping board to colorado ( US) with moisture ranges from 10-14% while shipping from India but once product received all get cracked . Continue reading MC in the home. 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. Please provide us with regular updates. My house is 24 years old. Why Do So Many Homes Have Cracks in Their Brick Veneer? Unless something is so out of whack shimming in back of the sheetrock won't suffice it's OK here. While the surface of the floor might feel dry, there could be higher moisture inside. We dont know if we still should be having a commercial drying process? Using a moisture meter before painting can help you determine the moisture content of the wood. 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. The door is NE facing and protected from direct Sun light and rain by a porch roof. The other was for a $100 retail gift card. Insert the pins into the surface of the wood you want to test. 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. Does Brick Veneer Cracking Mean Foundation Problems? I think that I know my own answer, but thought I might reach out for some possible better insight. The floor immediately felt stronger. The fir windows and exterior doors will be affected by the the exterior and interior RH. So, i had one installed a few weeks after we met. The company they hired measured 47% in the wood and declares that this must be ripped out and replaced. Thanks for the email. However, a general rule of thumb is that the basement's humidity level is not over 30 - 50 percent. Timber treatment | BRANZ Weathertight 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. PDF Subsurface Tolerances and Floor Flatness Requirements A Case for Below a 17% MC of wood, virtually no microbial growth will occur on even the most susceptible materials. When it hits the cooler air of the crawl space, it increases the relative humidity by about 2% per degree! Rotten Floor Joists - Repairing & Replacing Rotting Joists Uneven Floors, Sagging Floor Repair - Problem Signs and Solutions by JES I read your article and really like it. I dialed the 800 number for Wagner meters and all I got was two sales pitches for a Life alert type device. There are areas where organic growth was very active to cause deep, black discolorization. Turn on the meter. The front of the . A consistent humidity level of 70 percent will require wood to be about 13 percent moisture content. The supplier says they dry the wood to an MC of 14%, which is according to them the standard for outdoor furniture. Although some movement can be expected between 6% and 9%, wood flooring can shrink or swell more dramatically outside this range. Hello, Paul here. These mold spores land on the wet wood and take root. board, and a 12-in. -ThA?> =v\0r5#v ,J\Byt)%*?I!PT`FdCE N a^1IMm[?x>7RFH +=\ They said if i wanted to spend the money, a humidifier would help keep the humidity inside the house more consistent throughout the year. An MC in this range, therefore, is considered sufficiently dry for exterior in-service wood. They are currently nearing equilibrium (around 12 MC) and are stored within the house. Where floor s have been covered by previous floor coverings acceptable values are up to 3.5% and 80% in-slab RH. Such readings should alert the homeowner to look for a source of excess moisture. We havent gone any further since the condition was found so close to us purchasing the home. Limit the length of notches to 1/3 of the joist's depth. I have built two table tops (douglas fir) that have both suffered major cracking in their final location. What Moisture Content is Safe for Your Building Materials - Delmhorst of water/day/1000 sq. 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. Im trying to find specs on treated lumber for NC. Some of the unfinished wood you see on the market has been kiln-dried to reduce its water moisture content to around 8% so that it wont suffer from moisture-related defects like warping and buckling. What would be the recommended MC for doors of my new building(under construction)? 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. Where are you located? Heres how it works. 2-1/4", the moisture content between the flooring planks and the subfloor should not exceed 2%. The best way to do this is to use an accurate moisture meter. Are the measurements of all wood the same? hj0Ed=h].J-)_q},jR3$\ eH"wCk)E)J8 This is for furniture-grade hardwoods. in other hardwood areas that wasnt close to the water, was measuring about 16-19%. I so appreciate your treatise on this issue. i am baffled. It gains or loses water moisture as the relative humidity (RH) of the surrounding air changes. This method uses the oven-dry method and then compares the results to those obtained using a moisture meter. As a general rule, with geographic exceptions, wood flooring performs best when the interior environment is controlled to stay within an RH range of 30% to 50% and a temperature range of 60 to 80 degrees Fahrenheit. Structural flooring for laying direct to joists or battens is a minimum of 19mm thick. Wood moisture content is always varying. 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. This document describes the meaning and use of readings from a wood moisture meter. Wood shrinks or swells as its moisture content changes, but only when water is taken up or given off from the cell walls. Wiki User. Thanks in advance for your input! I dont know what type of floor you have, but if it gets wet enough, about 25% moisture content or higher, mold can grow. As long as the moisture content does not exceed those readings you should be ok. at one spot, its 40%. A floor joist is a horizontal beam, usually made of wood, that is used to support and enclose the flooring above a foundation. 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. Poor Drainage: A Foundation Problem Waiting to Happen, A Trade Secret: Bucks Vinyl Siding Test, Foundation Repair Salesman: Licensed to Kill, Dear God, Martha, Our House is Breaking in Two!. 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. Wood freshly cut or kiln-dried is always interacting with environmental moisture.