Formaldehyde is a volatile organic compound that can cause respiratory problems and other health issues, so using OSB instead of materials with higher levels of formaldehyde can contribute to a safer indoor environment.
Yes, oriented strand board (OSB) can be used for interior walls. It is commonly used as a structural sheathing material in both residential and commercial construction. Here are some key points to consider:
OSB is made from materials that off-gas in the mill, so they won't significantly reduce the quality of your indoor air.
While plywood and OSB both off-gas formaldehyde, OSB off-gasses more of the carcinogenic gas.
Sensitive folks usually choose plywood over OSB, but some brands of OSB listed below can be very good. A common type of OSB is the Huber Advantech. I find these need a solid 4 months to offgas to my standards (a lot longer than plywood).
The testing by the APA, as well as other laboratories, showed that OSB emits less than O. 1 parts per million (ppm) of formaldehyde within the large-scale heated test chamber. This is for both new and aged OSB. Formaldehyde that is emitted by OSB is below HUD standards for allowable emissions.
If you're especially sensitive to scents, a bed with strong off-gassing odors may cause unwanted symptoms, such as headaches, nausea, or dizziness. Individuals with respiratory issues, such as asthma or allergies, could also experience irritation of the airway and difficulty breathing.
OSB with PMDI releases toxic byproducts when it is burned, cut, or otherwise machined. Which means when your house is built, or anytime you poke a hole in the OSB, you are releasing chemicals that can harm your body.
Oriented strand board (OSB) is a problem for resilient and wood flooring installations because of the nature of its construction. Traditional OSB is made from large chips of wood that will swell when exposed to humidity and moisture, causing the texture of the chip structure to show through on resilient floors.
OSB is, to all intents and purpose, more than adequately airtight as far as a building air test is concerned. It won't let air through at a rate that would make a jot of difference to the house air tightness in practice. OSB is vapour permeable though, so will allow water vapour to move through it.
Prone to swelling edges and telegraphing.
“The major disadvantage of OSB is that if it gets exposed to significant amounts of water or moisture, the edges expand by up to 15% ... especially if they are cut edges. This swell will then telegraph onto the shingles or some flooring," according to PATH.
Using OSB Safely
The side stamped “This Side Down” is typically the smooth side. This is mostly for roofers so that they lay the smooth side down and can stand on the rough side facing up. When installing in vertical applications such as wall sheathing, you'll want to orient the smooth or stamped side facing out.
Using Oriented Strand Boards as an alternative gives you a little more leeway when installing since the process is not as complicated as doing a sheetrock installation. Drilling and screwing through OSB's also produces less dust when compared to doing the same to sheetrock.
Improved resins, better water-resistance, and especially lower costs have helped make OSB the first choice for many builders even though plywood production can be counted in the billions of square feet annually.
In high-moisture areas like bathrooms or kitchens, it's crucial to seal the edges of OSB board properly and maintain a dry environment. Regularly inspect for any signs of water damage and promptly address any issues to prevent deterioration.
Ideally we'd have no vapor barrier in summer; but short of that we should at least have one that allows as much drying to the interior as possible without sacrificing its winter performance. So the closer your vapour barrier is to 60NG, the better.
Disadvantages of OSB
Not moisture proof - OSB should be kept dry and does not perform well with prolonged wetting. It can swell, warp and lose strength if left unprotected. Weaker across the width - OSB has less stiffness across the panel compared to plywood. Additional bracing may be needed for some applications.
Many building products emit VOCs. Products containing formaldehyde all give off VOCs. This includes such products as engineered doors, engineered floors, plywood, particle board, OSB and others. Solvent-based products and many glues emit VOCs as they dry.
Oriented strand board (OSB) is made of wood, but it is cement-bonded for extra durability. For this reason, termites aren't likely to eat it.
OSB swells more than plywood when it comes in contact with moisture, and it generally remains swollen to some degree. While both OSB and plywood off-gases formaldehyde, OSB off-gasses more of the harmful gas than plywood.
Exterior plywood and OSB do not contain urea-formaldehyde (UF) resins. Instead, they use phenol-formaldehyde (PF) or isocyanate resins. Phenol formaldehyde has extremely low offgassing. Isocyanate resins have no formaldehyde emissions at all.
VOCs can linger long after a fresh coat of paint dries, impacting indoor air quality for days, weeks, or even months.