OSB

Use plywood

Batten them.

The Order of Saint Benedict probably likes the idea that your walls are insulated but they look beyond creature comfort.

Oriented Strand Boards come in a variety of different grades. Pivotal in that grading is the quality and type of binding agent (glue) used. It sounds like you have used the wrong type for your application. Chalk this one up as a learning lesson and use the correct grade.

I lined my 10x10ft shed with OSB fixed to vertical timber battens at about 2ft spacing over 2in of foam insulation. This was installed 5 years ago & has not warped.

i wish i could say the same 9 screws in each osb sheet and still warps/bows from top to bottom. is there a way to straigthen the osb or does it get replaced?

But....that would cost too much.....The price I bid.....only 9 per sheet...

read the thread you moron its personal use not a bid job!!! im not a carpenter just saying 9 screws 3 across the top , 3 in center and 3 at botto and have 2 gossits per side nailed together , the top center and bottom are screwed into c channel.

Your pretty much screwed when you short screw any type of sheeting. Your studs or joists should be no less than 24 inches on center with blocking every 24 inches in between the studs. You can salvage the OSB but you'll need to remove it, lay it flat while you fix the studs and blocking. Then reinstall the OSB using at least 36 screws per sheet as Doorman suggested. And being it's already warped, start screwing from the center out, working out the bows as you go. Good luck

How to Hang OSB Board Properly | Home Guides | SF Gate

Floor, Roof, and Wall Panel Installation - Weyerhaeuser

Lyn has found and posted some accurate info. Here's some more:

http://osbguide.tecotested.com/faq15

From first hand experience, I consider the suggested 1/8" gap a minimum. Did you butt the sheets tight? These sheets will expand after installed, and even 136 screws per sheet won't stop it.

Almost afraid to ask... sheet thickness, please? Did you throw paint or some type of protective coating on?

Your original plea was how to arrest the bowing, but is redefined as reverse the bowing. Very difficult to do the first, and I would say not possible to accomplish the second.

I used OSB in my shop, I primed with kilz and painted with Glidden 7011 gloss white, secured with screws every 3 inches, been there 7 years no warping.

The poster said he secured the OSB at "9" contact points ( not 9 screws) , using "C" channel.

I did not see a mention of the size of the OSB, 4x8 sheet ? what was the thickness ?

It would be interesting to see a picture or a diagram of the 9 contact points.

I think that one would give you nightmares.

It's a feature....

Why OSB????? My God---Are you trying to save money? Look at the problems with the material---Do some research….It is not allowed for floor or roof sheeting around here…Shear is abysmal, as it will not hold a real fastening, and if left in the open for any length of time, will degrade to the point of having to be replaced--It is the poor man's sheeting from wood scraps originally from the pulp mills in the N.US and Canada, that some how found their way into the US building industry. Always use real PLYWOOD, as the material is known, has a lifespan, and has a history of performance. Worked in the industry for over 40 years, and have seen it all...

Depends on the grade of OSB. There are 4 main grades starting with OSB1 which is for interior use only & ending with OSB4 which is suitable for exterior work.

I don't agree with just about everything you wrote about OSB boards.Its like you have never ever used them!!! Or even seen them....

I have been making stuff like cupboards, walls and floors with it for the best part of 20 years. All is still fine. Very strong and very stiff for its thickness.....but I probably use even more screws than needed, even on floors....I rarely glue it as I want to be able to remove a cupboard without needing hand grenades or dynamite.....screwing was always my favourite!!

Its wonderful stuff when properly used......I have even put bits outside and let them weather as a test. All I can say is no twisting or delaminating, just some colour change after several years of full weather treatment. Still usable.

I am even surprised that the OP has problems, but it sounds like he did not mount it properly. When building/covering walls I like to have it screwed to very secure battens, that I have applied myself, perfectly vertical and flat in all directions...to within a millimeter...that is what takes the time.....also good insulation between it and the original wall. My kitchen is so made and has all the hanging cupboards mounted on it. 9 years no problems....painted on one side only and no damp areas....all the wiring for the oven, washing up machine and 27 sockets are hidden behind it.

I have an old farmhouse with timber framed walls, difficult to mount cupboards otherwise.

I used a laser to get everything right in all directions both horizontal & vertical and the 90° between joining walls..... Wonderful things laser levels.....

It sounds like you were talking about fiber board, chipboard, particle board or similar. There are some poor products out there that fit in with your observations. But not OSB!!!

Here is a link that will help you get up to speed:-

Engineered wood

• Oriented strand board (OSB) is a wood structural panel manufactured from rectangular-shaped strands of wood that are oriented lengthwise and then arranged in layers, laid up into mats, and bonded together with moisture-resistant, heat-cured adhesives. The individual layers are cross-oriented to provide strength and stiffness to the panel. Produced in huge, continuous mats, OSB is a solid panel product of consistent quality with no laps, gaps or voids.

What we call "Spannplatten" here (Chipboard) are totally useless and cannot be compared with properly made OSB. That is probably what you are thinking of......

Problems seen on some OSB boards.

OSB, or better said, that from some companies, usually the cheaper stuff, is a bit "raw" surface wise, but I simply wet it, fill it and rub it down then paint it.....and watch out more carefully for the manufacturer/surface quality next time.

Also, when cutting with circular saws, you get small razor sharp pieces that go in your skin or under a nail....irritating!!

Which is why when I build a cupboard, I go to the DIY shop and let them cut all the widths I need exactly, and trim it only to length myself......saves a few injuries! And costs me nothing except a small tip, which is often not accepted as it is their job anyway!!

I have built with both plywood and OSB for years. You may be confusing OSB with MDF(Medium density fiberboard) which comes in various densities, often used in cabinet making. . Our roofers would never use OSB as a substrate for any type of roof due to the problems with moisture. It swells locally , edges up to 15 % , when wet, whereas plywood of the same grade, expands and shrinks much more evenly. For cabinets, we use Baltic Birch..Top shelf stuff. OSB will not be tolerated by our flooring contractors , either tile,stone, or wood, because of the moisture problems , and it's inability to hold a fastener. Screws and nails break the chips, and blow out the backs, and are able to be moved in various directions. OSB is recommended to always have waterproof membranes used in conjunction. For the $ 700 saved , on average, for a house, I cannot understand why it is used except for stable interior work, on walls….MDF has it's own set of problems. It was often used as backing for veneered flooring (picture board as we called it), and woe to the owner that had a leak. Good Engineered flooring is backed with 5 or more layers of Baltic birch-likw plywood, not OSB or MDF. Must be a reason….

My shed roof is OSB with roofing felt over the top. Been just fine for 5 years.

Be careful if something violates that felt layer, and kit is not notched. You will be having problems. We have torn roof off of house sheeted both with plywood and OSB, and the OSB was no longer viable as structural diaphragm,as it could not retain it's shape or strength after drying out, where the plywood could. Just needed to add fasteners. Seal the edges real well, and put some drip cap around the edges too, if not already done. Good luck..

I've had the felt tear off a large chunk & had to patch it. The OSB was OK. The reason for the tear was a bit strange, I have some bird feeders hanging under the shed eaves & the birds tend to queue on the edge of the roof waiting for their go at the feeders. The edge of the felt where the birds queue had worn through, I guess from their claws.

That would be interesting to see! Maybe put a piece of thin galvanized sheet metal up on top, for them to try and keep a grip on.

No good deed goes unpunished.

I too have a shed roofed with OSB, unpainted or treated in any way and it's been in place for at least 5 years without any trouble. One of these days may find the time to put either roll roofing or shingles on it.

That is my experience with OSB, indestructible!!

I think the problem many have is they mix up MDF and other crap boards with OSB!!

Re: cupboard mounting. French cleats might make mounting and dismount much easier.

If the OSB was not sealed before you installed it and the warping is due to moisture you will have to remove and stack the panels with weight on top to flatten them first.

After the panels have had time to flatten out they can be coated with primer and paint to prevent moisture impingement then reinstalled.

This being said it could be that the warping is being caused by the movement of the metal C channel as the expansion rate of metal is significantly different than the OSB.

If the warping is due to the metal moving it will require additional metal support between the C channel to stabilize the walls and provide enough support to stop the warping from occurring.

Identifying which is the root-cause of the warping is very important.

I agree with your post.

He should remove a few panels and see if they are flat when not attached to the metal....

I would guess that the metal frame has wide almost unsupported areas, I never do that.

I build a solid frame of wood and screw the OSB panels to that, the frame is solid and I get no warping.

I have never ever attached to metal of any sort.....

Furthermore, some OSB panels are quite thin, I never use these. I use either 18mm or 22mm from memory....mainly then I can "end screw" when needed....not that it is often needed....

If I had to hang wide panels with little support, I might glue & screw some battens to the back of each panel....

THERE ARE 4 BATTENS ON EACH SHEET ON THE SIDES THEY ARE NAILED TOGETHER THE BOW IS FROM SCREW TO SCREW THE ENTIRE LEGTH OF THE 8X4 SHEET

Can you give us a picture of a complete board, showing the battens and the screw positions. A picture is worth a 1000 words......

Are you 100% sure that it is OSB and not chipboard, as the failure you are seeing is a very typical Chipboard problem, seen it many times.....which is why since OSB is around, I never use it anymore.....

Also, you have mentioned 4 x 8, I guess Feet, but how thick is the OSB? I believe you have never mentioned this, it is exceedingly important to know that. I would guess, yours are too thin.....

Thanks.

I can't help feeling that some people here are mistaking other products (I can think of few!) with the name OSB.......there are some really crappy board/panels around.....as I have previously mentioned....

Perhaps some pictures of the failing ones.....from all the negative commentators, and the OP of course.

One problem that I have seen is that people in construction, often have the torque up too high on there Battery power screwdrivers, because they haven't got the time to bore drill holes and the like.....I take time (using two battery powered drills to countersink and bore.....I also use the torque (and my head!) to not "OVER" drive the screws....

There are even some drill bits that perform all the operations needed with one tool once per screw....never bought any myself.....you need one for each screw size I believe, too expensive!!

Lets wait on the pictures....

I think you are right in the nomenclature idea. The OSB we refer to has wood chips of quite a large size, and maybe that is what you are, in Germany, referring to. If so , then you know what I (we) are talking about. Drills and bits--Craftsman Drill /driver, are what we use.. With our plywood , we use self drilling screws, with cross threads that cut their way through. Use a lot of hex head hardened screws for structural HD's ( Simpson Seismic Hold down brackets--No drilling needed, installed with an Impact driver) Also use similar ones for concrete (thin). There are other types of board also, MDO (Medium Density Overlay) and higher densities are available. These are sometimes impregnated or coated with epoxy, and are used for workbenches etc, even as removable and reusable concrete forms. Don't know the equivalent in Germany. Thanks for pointing out the problem.

Then what you call OSB is not OSB.

If you read the link I posted previously, it describes how OSB is made quite clearly - no chips!!

You are talking about "Chipboard". It is so useless, you cannot even make a good fire with it!!!

Problem solved.

I think you are also not alone with your problems with chipboard.....

Chipboard - simply resembles dried porridge!!....

OSB - Its easy to see the difference and how the longer, wider strands are laid at 90° to each layer.

It makes a strong and stiff board, also VERY resistant to water ingress.

From that link:-

Oriented Strand Board (OSB) is a wood structural panel manufactured from rectangular-shaped strands of wood that are oriented lengthwise and then arranged in layers, laid up into mats, and bonded together with moisture-resistant, heat-cured adhesives. The individual layers are cross-oriented to provide strength and stiffness to the panel. Produced in huge, continuous mats, OSB is a solid panel product of consistent quality with no laps, gaps or voids.

Its great to solve such a puzzle, thanks again for your help...

I still cannot get the image of several gentle monks attached to C channel struts with just nine screws out of my warped mind.

Andy--The lower picture IS OSB, as we call it. Google " building materials" and their plus and minuses, and you will see why we here, in the US, are not allowed to use it for specific applications. You are in Germany--Where is your OSB manufactured? To what specs? Do they provide a moisture test? The upper picture is what we call " PARTICLE BOARD". I suspect that Germany, based on the quality of product, has a totally different OSB board than we are getting here in the USA , and in Canada. Can you provide a source and location for the manufacturer? If it is the Netherlands, or close, we are not talking about the same OSB.. No problems, just different specs with the same nomenclature…. Thanks for hanging in with this...

This is what is available in the UK in various grades. No clues as to where it is made but I'll look at the boards lining my shed tonight to see if there are any visible markings.

The bottom line is that the engineered material and fastening that rayp used in this construction is insufficient for the task. My two top suspicions what went wrong for rayp. The conditions are not what rayp thinks. A leak, condensation or other cause is making this a wet and not humid installation, thus any grade of OSB is not suitable. The other possibility is that regardless of what the bill of materials says these sheets are not the correct grade of OSB. This could be an honest mistake in the lumber yard or how the yard affords their cheap prices.

Regardless of why these boards are warped, this type of engineered lumber should get replaced by somebody that knows the material and how to properly install it. They failed once, they will fail again. If rayp is willing to chalk this up to a learning episode then he should try to install with a better material, fasteners or both. He should then accept that a repeated failure will be just his fault. If not, then hire a carpenter.

Nigh--It Looks similar to we have here, but if you look at the specs, it says "exterior", then says "NO" to water resistance. Can't have it both ways, I am afraid…. Plywood is graded as interior or exterior, due to the glues used. The exterior plywood of old was made using hot pressed resorcinol glue, and used extensively in WW 2, for both P.T Boats, and certain aircraft. It was graded as "waterproof". Don't know what they use today...

They moved on to engineered composites

They found a cheaper way to fabricate with titanium. Just use titanium sheet metal.

I was referring to the types of glues used in todays composites, not the industry as a whole.

Do you remember posting this?

Andy--The lower picture IS OSB, as we call it. Google " building materials" and their plus and minuses, and you will see why we here, in the US, are not allowed to use it for specific applications. You are in Germany--Where is your OSB manufactured? To what specs? Do they provide a moisture test? The upper picture is what we call " PARTICLE BOARD". I suspect that Germany, based on the quality of product, has a totally different OSB board than we are getting here in the USA , and in Canada. Can you provide a source and location for the manufacturer? If it is the Netherlands, or close, we are not talking about the same OSB.. No problems, just different specs with the same nomenclature…. Thanks for hanging in with this...

Where did you get your information from that you posted here, most of it to my mind completely incorrect? and or misunderstood?

Have you now understood better what OSB is really about?

How it is made (much/most in the USA) to what are basically international standards/specs with respect to all parts of OSB over the whole world?

I have been using it for probably around 20 years to make many things (I don't remember exactly), other than the fact that clean cut edges can cut your skin, and the surface on some is a bit raw, its the best building material I know....

Having seen the building construction idiots here using their powered screwdrivers on such a high torque that they either ripped the screw out or broke off the head in OSB (problems I have never ever had!), it may not be a material for stupid construction workers.....

You do need to drill pilot holes and countersink for clean working, which of course means more time required.....but good work with high grade plywood requires it too.....nowadaysOSB is considered a replacement for plywood in many situations....

If I were sheeting a roof, floor, and using this stuff for the entire shear wall requirement for a house, let alone sheeting for stucco backing or what ever, having to drill pilot holes for all of that would take an incredibly long time. If it can't' be fastened in one pass, either by screw gun or nail gun, it is useless for most of the building industry. A 3000 sq.ft. house uses cases of fasteners for these uses, and one must be able to do it quickly. They even use one pass fasteners for metal framing, similar to Tec screws. Maybe pre-drill when I am doing my finish boat work,, or for cabinet trim work, using wood screws, and the various drill stops and plug cutting tips. Not houses. What is the difference in price , where you are, between the most expensive, high quality SB, and the lowest grade?

Using the correct quality of plywood, in the same situations, will save on costs, but also requires pre-drilling for good holding of fastenings and quality workmanship.

I have seen construction workers many times over the years - fast & furious is the only kind words I know.....

OSB is a relatively hard material in comparison with cheaper board types and requires therefore better quality building techniques, as does plywood of course. It is not something like particle/chipboard that accept such bad work practices, but miss out on the stability that both quality OSB and plywood brings.....

My impression is that you have never ever used the proper product called OSB. If you had, I do believe you might be far more amenable...

I would not be surprised to learn that the cost savings of OSB allow construction in it, where even plywood might have been too expensive....

Also, I have found that a little bit of thought gives a really strong construction - for example, I always tested any shelf with my own full body weight, sometimes with the wife as well....

Luckily, to speed up construction for some, there are "one operation" drills available that bore the correct hole, the correct clearance hole and the countersinking, all in one, that could help someone in construction to make a better job....but were too expensive for me personally years ago...they need to be in use far more often than I would have.....

I found some online:-

I am sure that there are other, maybe even better, versions available nowadays.

Perhaps someone here has previous experience of actually using them....

Hi Andy--I have been in construction for 40 years, and have laid thousands of sheets of plywood, and OSB, as well as MDF , HDF shelving etc. We nail OSB with nail guns set to certain pressures, with nails that have specific shank thicknesses for shear and compressive strength. As mentioned before, pre drilling for any roofing, or flooring, or shear walls, would take so long as not to be profitable. The fastener must be able to load and shoot or screw in one step, not two or three. I have the same tools you show, as well as about a dozen of more specialized ones. I have observed every new material available to us and it's application process in those last 40 years. Some are still with us, and others have gone . We have had to be proficient in application of each of those, for we have some of the most stringent applications and requirements in the world, California, USA. Our earthquake codes would make a European inspector go nuts. Look at the Simpson hardware catalog for examples. Believe me, if there is a stronger or more effective means of structurally constructing a building, or better materials, I would know about it, because our Engineers would have those methods spec'd out for the next job. The last shear panels we installed replaced 4 foot shear walls, of either OSB or Plywood, and are called Hardy panels. They are all custom steel welded, and come with preinstalled threaded studs for both top and bottom plates, with washer and nut specs of Grade 5 . I am sure your OSB projects are great and if they serve your purposes, more power to you. But in residential and commercial construction here in California, we have a different set of needs considering our location in Earthquake country. Don't get me wrong, a lot of OSB is used, but not so much in critical areas. Good luck with your projects. It is great to see people like yourself, using their minds and their own hands and skills to construct things without relying on the IKEA mentality!! All the best, Mac

Are you really trying to imply that building codes change with location. What a novel idea.

What a wonderful insight into structural practices and material availability/developments in your part of the world.

Very different here. Loads of reinforced concrete used here even for small bungalows. OSB...never seen it, Plywood....shuttering and cheap shelving, Loads of steel used here too. Special hardware all has to be custom smithed.

Material (skill) availability rules the method.

You are very correct. Some of the most earthquake resistant buildings are Yurt designs, beginning in the Middle East as portable structures, and more currently , making more permanent structures using only basic materials (dirt, rock, dung, and straw, if available), available onsite. Malaysia, it seems, is quite adept in Engineering and construction , as Kualu Lumpur hosts 3 or the world's tallest buildings! Vietnam may not be too far behind!

There re 4 different specs for OSB for different usages.....

Four grades of OSB are defined in EN 300 in terms of their mechanical performance and relative resistance to moisture.^[8]

• OSB/1 - General purpose boards and boards for interior fitments (including furniture) for use in dry conditions.
• OSB/2 - Load-bearing boards for use in dry conditions.
• OSB/3 - Load-bearing boards for use in humid conditions
• OSB/4 - Heavy-duty load-bearing boards for use in humid conditions.

......which is why I mentioned that it comes in various grades, including exterior water resistant.

I have just posted in another post here that the USA & Canada are the world's largest manufacturers of TRUE OSB Panels....

There is a good Wiki article with many links in it.....

OSB is OSB the world over....

I posted the specs for many different board types, including OSB in an early Wikipedia link. the standards are worldwide.

WE ARE TALKING ABOUT THE SAME OSB, WORLDWIDE......

The name tells anyone how it is made, chip does not form any part of the name or the process....

Oriented strand board (OSB), also known as sterling board, sterling OSB, aspenite, and smartply in British English, is an engineered wood particle board formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations. OSB may have a rough and variegated surface with the individual strips of around 2.5 × 15 cm (1" × 6"), lying unevenly across each other and comes in a variety of types and thicknesses.

--------------------------------------------------------------------------------

OSB is a material with high mechanical properties that make it particularly suitable for load-bearing applications in construction.^[1] The most common uses are as sheathing in walls, flooring, and roof decking. For exterior wall applications, panels are available with a radiant-barrier layer pre-laminated to one side; this eases installation and increases energy performance of the building envelope. OSB also sees some use in furniture production.

That was taken from here:-

https://en.wikipedia.org/wiki/Oriented_strand_board

The following statement was also made in this same link, which (assuming you live in the USA) means that you are not talking about OSB correctly or knowledgeably:-

Most of the world's OSB is made in the United States and Canada in large production facilities.

The USA is therefore a rather large manufacturer of OSB and user, contrary to your own thoughts!! You Guys make complete houses of it!!! There is a picture of one also on that link.....

Adjustments to the manufacturing process can impart differences in thickness, panel size, strength, and rigidity. OSB panels have no internal gaps or voids, and are water-resistant, although they do require additional membranes to achieve impermeability to water and are not recommended for exterior use. The finished product has properties similar to plywood, but is uniform and cheaper.^[6] When tested to failure, OSB has a greater load-bearing capacity than milled wood panels.^[7] It has replaced plywood in many environments, especially the North American structural panel market.

Four grades of OSB are defined in EN 300 in terms of their mechanical performance and relative resistance to moisture.^[8]

• OSB/1 - General purpose boards and boards for interior fitments (including furniture) for use in dry conditions.
• OSB/2 - Load-bearing boards for use in dry conditions.
• OSB/3 - Load-bearing boards for use in humid conditions
• OSB/4 - Heavy-duty load-bearing boards for use in humid conditions.

I trust that the link and the short paragraphs I have copied here have improved your knowledge with regard to OSB usage in the USA.

The standards are universal as far as I can tell, the USA agreeing with the rest of the world and vice versa....

Which grade does the OP refer to here? ( I had already read the Wiki notes)

Good question. I wonder why nobody brought this up before.

Only he might know, though that is not a given....

You bought cheap; you got cheap.

Check out these two sites: The first site is one that gives the name and location to every major wood manufacturer in the world. The second provides information on OSB in PDF formats and free literature in French, English, German, Italian and several other languages.

The latter site can sit well with engineers, who are well versed in the language of math, can read in the phonetic language of their choice so the understanding is universal.

I like the term " free" whether it is the first syllable in a two syllable word or the first in a two word set.

1. goforwood.com

2. http://osbguide.tecotested.com/reflibrary

I checked the make of the un-warped OSB in my shed, (also noticed a damp patch on the roof inside, I'll have to check the roof felt at the weekend). The OSB is by Norbord who seem to manufacture in several countries.