If I use OSB for the walls of a 10x12 workshed, with no interior sheathing... how long will I be breathing the fumes? Does it off gas a lot initially or is it steady over it's life. If I cover it with siding of some kind, does this prevent the off gassing to the outside and just channel it to the inside.

jc

I assume you're referring to the formaldehyde?

It'll off gas the most in the beginning... but you shouldn't notice it. It's a workshed, so there'll be drafts, etc. You'll be fine from day one.

Thanks for the silly answer, it inspired me to look further for the answer. Recommendations I've read are for storing plywood and OSB outdoors for as long as possible, 2 weeks at least, before use as flooring, roofing, or walls. The formaldehyde off gassing can continue for months. Formaldehyde, especially the concentrated urea formaldehyde used as a glue in plywood and OSB, is a known carcinogen.

Im not sure why the gassing of the osb is such a concern unless your buying direct from the manufacturer the osb sold at home centers is usually shipped and stored for a sufficient time to allow most of the out gassing to take place. Is it wise to store it outdoors after purchasing sure the longer the better. I think the real question for that is would it be pratical to purchase then store it for 2 weeks before using it. I think for most people the answer to that is no. The glues used in all plywoods, carpets heck just about anything is a carcinogen. As far as your specific question Yes it releases more in the beginning most of the initial release will most likely be over by the time you purchase it. It will still release lesser quantities for a few months. These quantities are usually not enough to bother anyone and are rarely noticeable to most people. When I built my last storage shed 12x16 osb for the sides and roof (roof shingled and vinyl siding over the osb walls ) I started using it within 2 days of framing and drying in and had no complaints but maybe Im just not sensitive to it. If its really a srious concern for you visit the american plywood associations website for advice on formaldehyde free panels. Anyway that's just my 2 cents and I hope it helps in some way GOOD LUCK, AC

You're right, if OSB sits at a home center for a while it will be outgassing. But I'd guess that there is high turnover at a home center (that's why their prices are low) so I don't think I'm going to count on the time OSB spends there... but it's a start so it's a good point. I'll probably have to call the manufacturer and find out how long it sits in their yard before they ship to the home center.

You're also right that there are carcinogens in a lot of products, especially new carpets. Some people are more concerned than others. I eat organic food, and there's no way I'd put new carpet in a house I was going to be living in, especially if it was going to be glued to the floor. Especially if there were children living there. Just because it doesn't bother you doesn't mean you're not breathing it. The time to worry about these things is 30 years before you get that brain tumor, not the week after the diagnosis. Do a little research on the subject and you'll be amazed how your concern will grow.

If you have power try a glade plug in. by the time the plugin wheres out the smell will b less anyway, or u will b used to it.

I am convinced that you will be inhaling a greater quantity of carcinogens walking down a city sidewalk than working in an OSB-sheathed shed. Certainly, the off gassing will diminish over time. That being said, if you are concerned, why not use shiplap for your sheathing. It will not provide the stability in shear that OSB or plywood would, but that can be provided by thin metal cross bracing under the sheathing.

I am also convinced that some are more succeptable to small doses of carcinogens than others. It's the luck of the draw, and each must deal with it as he chooses. Life is definitely a crap shoot.

The smell is coming out of the drain from the water tank, the water in the s trap has evapourated , pour 1/2 litres of water dowm the drain every 3 month, You are breathing in sewer gases which is also flammable.

In the past 15 years, almost every house in the US has been constructed with OSB sheathing, roof and walls, and many homes have Advantec flooring systems, also containing some formaldehyde levels. Yet, in the same period, cancer rates have fallen. CDC relates 30% of lung cancer and 80% of the mortality from smoking. Do you inhale formaldehyde? Yes. You also inhale exhaust gasses when driving, cutting your grass, weedwacking and chain sawing, organic vapors when filling your gas tank, Ozone, Freons, grease vapor when cooking bacon and the list is endless. One of the primary reasons people breath aldehyde in the home is the use of only central air and never opening a window. In a shed, solar load and wind will disperse aldehyde levels below measurement. Smell, yes but not at a hazardous level.

I just put a loft in and used OSB due to the information I found about it's relatively low off-gassing. It does not contain urea formaldehyde, like plywood does and is stated to be non toxic. However, my eyes are burning and so red you'd think I sprayed hairspray in them which has increased over the last two weeks, and I wake up every night with the sheet pulled over my head, wheezing. So, cigarettes and carbon monoxide may cause lung cancer, but OSB is doing something immediate and scarey.

Good for you for asking such questions. The outgassing will be more in the beginning, then tapering off, but could be months if not years to completely go away. I heard of a University of California, Irvine study that tracked air quality in a mobile home for 10 years, and the formaldehyde levels were scary. I would use exterior grade OSB, ventilated the shed, and let it outgass before install. Specifically exterior grade OSB with "Formaldehyde Exempt" written on it. I've read this means it will have phenol-formadehyde in the glue/resin which is suppose to be lower outgassing than the urea based formaldehyde. The latter is more commonly found in interior OSB (go figure)! I would cover the exterior with some type of water proofing (e.g. siding) if the shed is outside because the other concern with OSB that I've read is significant mold buildup. But, I would think the more you try to waterproof it (ie stop water or air getting in), then less vapors would be able to get out. Thus, I'd let it outgass for a couple of weeks in the garage (hey I do the same for my mattress toppers). I'd also install a small fan ventilator ( more comfortable too). I ran into the same thinking when I soundproofed our garage for my husband's band. But as an environmental engineer and attorney, I'm glad some one is asking questions. Try healthyhouseinstitute.com

This thread is over 1 year old. Outgassing is virtually over.

It is precisely the CUMULATIVE EFFECT of toxins that cause health problems in most people--exposure to the daily combinations of smog, household chemicals, agricultural/lawn pesticides... and the formaldehyde so common in all kinds of furniture and building products. It is ridiculous to suggest that, oh well, you're exposed to poisons everyday so what's a little more in the walls of your buildings.