estwing said:
Ok, if you have a swivel arm of about a meter, it might cause issues.....who has that on a 50"?
The Beijer link above clearly shows that the difference between OSB and plyfa is marginal in this context.
many have arm extensions on their plasma devices...MathiasS said:
but who hangs something that's 100 kg then?
the TV + mount weighs around 60 kg.
the best is with plywood where you're going to hang kitchen and TV, etc.
then you can use chipboard or OSB.
regards
estwing
Who hangs something that is 100kg? Not me. You can hang a small car on ten screws in an OSB.
Come on, Estwing. It's 13% higher tensile load and 1.5% higher shear load. That's practically nothing.
I have also used plyfa where I thought there was a slightly higher load, in the kitchen and bathroom in my case. In hindsight, it's completely unnecessary. A little better, yep. Very little.
Sometimes you need to think about why you do things the way you've always done...
Come on, Estwing. It's 13% higher tensile load and 1.5% higher shear load. That's practically nothing.
I have also used plyfa where I thought there was a slightly higher load, in the kitchen and bathroom in my case. In hindsight, it's completely unnecessary. A little better, yep. Very little.
Sometimes you need to think about why you do things the way you've always done...
Last edited:
give up now.
screw in a drywall screw and take the claw of the hammer and pull it out and you'll notice the difference...
paper and reality are not the same...
you were the one who mentioned 100 kg not me, that's why I asked .. hehe....
screw in a drywall screw and take the claw of the hammer and pull it out and you'll notice the difference...
paper and reality are not the same...
you were the one who mentioned 100 kg not me, that's why I asked .. hehe....
Paper? A number doesn't become untrue just because it's on paper. It's quite reasonable to assume that practical tensile tests form the basis for these numbers. It seems better to trust those who have pulled out screws and measured how tightly they hold than your right arm?estwing said:
I don't really understand what you're objecting to. Are the numbers incorrect, is the difference too small, or what is the problem? :x
Completely agree with estwing. Those numbers are frightening to see. And the fact that anyone even believes them is probably even worse. I would rather put 2 layers of plasterboard and molly instead of OSB. A number doesn't become true just because it's written on paper either.
The numbers do indeed come from http://www.sp.se/sv/Sidor/default.aspx .......
Ohhh....you need to pull yourself together a bit if a discussion is to be meaningful.
I haven't said that OSB works as well as plyfa. In terms of strength, plyfa is better than OSB and chipboard, and how much better has SP shown us through practical load tests. Read again - practical load tests.
They haven't guessed, not calculated, not opined, believed, or cared about how many walls someone has built. Instead, they have tested in an organized manner how much better plyfa actually is, for example, when you’re going to hang up kitchen cabinets.
Can you think of a better way to test this than to fill a cabinet with things and see when it falls down?
In practice, one could then conclude that a regular kitchen cabinet breaks before the screw comes loose from the board. So it doesn't matter which board you choose in this particular case.
Whether you've built one or a thousand walls doesn’t matter, they are all the same. Estwing didn't want to answer the question, so I can ask you again Chris - what is wrong with SP's testing method? Doesn't it show how these boards behave when you hang a kitchen cabinet on them (http://www.byggahus.se/forum/byggmaterial-byggteknik/145270-bygga-koeksvaegg.html)?
It's a bit hard to understand this skepticism towards numbers and theory, especially since in this case it isn't theory but as practical as it can get. What's the problem with numbers on a piece of paper really? Obviously, there is an opportunity to learn something new when reading things that are on paper - one shouldn't be afraid of that.
Who do I trust? In this case, I trust SP's engineers all day long who give us black on white what applies, especially when it comes to cabinets on walls (a load case that can also be reused for TVs and other things indeed). SP has also realized that a wall doesn't hold better just because you've built 1000 of them.....
I myself have also used plyfa when I've thought I should hang up heavy things. I also believed things held much better in plyfa....
So, come on now, give me some solid answers to the questions above.
I haven't said that OSB works as well as plyfa. In terms of strength, plyfa is better than OSB and chipboard, and how much better has SP shown us through practical load tests. Read again - practical load tests.
They haven't guessed, not calculated, not opined, believed, or cared about how many walls someone has built. Instead, they have tested in an organized manner how much better plyfa actually is, for example, when you’re going to hang up kitchen cabinets.
Can you think of a better way to test this than to fill a cabinet with things and see when it falls down?
In practice, one could then conclude that a regular kitchen cabinet breaks before the screw comes loose from the board. So it doesn't matter which board you choose in this particular case.
Whether you've built one or a thousand walls doesn’t matter, they are all the same. Estwing didn't want to answer the question, so I can ask you again Chris - what is wrong with SP's testing method? Doesn't it show how these boards behave when you hang a kitchen cabinet on them (http://www.byggahus.se/forum/byggmaterial-byggteknik/145270-bygga-koeksvaegg.html)?
It's a bit hard to understand this skepticism towards numbers and theory, especially since in this case it isn't theory but as practical as it can get. What's the problem with numbers on a piece of paper really? Obviously, there is an opportunity to learn something new when reading things that are on paper - one shouldn't be afraid of that.
Who do I trust? In this case, I trust SP's engineers all day long who give us black on white what applies, especially when it comes to cabinets on walls (a load case that can also be reused for TVs and other things indeed). SP has also realized that a wall doesn't hold better just because you've built 1000 of them.....
I myself have also used plyfa when I've thought I should hang up heavy things. I also believed things held much better in plyfa....
So, come on now, give me some solid answers to the questions above.
I think, with emphasis on think, that there isn't a significant difference when soundproofing gaps in one or two layers. However, if you do it in both places, it might be more forgiving of any mistakes.Stommen said:
Another aspect. If you haven't soundproofed in the lower layer and later find you have issues with sound, you can't redo it and won't have peace of mind not knowing how it would have been if you soundproofed both layers.
Electrical boxes leak sound. If you can, you should avoid placing boxes in the same stud bay and especially boxes directly opposite each other where the backs almost meet.
If boxes are in different stud bays, I probably wouldn't bother sealing around the cutout for the box.
I wonder if you can apply some self-adhesive window rubber sealing strip around the box before mounting it. But that would probably require inhuman precision for the hole and box to be centered. :|
Regarding the discussion about OSB and plywood, I agree with MathiasS that there is no reason to question the testers from SP.
There are many myths in the construction industry that have been debunked in this forum. Unfortunately, the myths have a tendency to resurface time and time again.
There are many myths in the construction industry that have been debunked in this forum. Unfortunately, the myths have a tendency to resurface time and time again.
Regarding the choice of screws and boards, I can say this:
(my limited experience and knowledge)
I screwed the OSB with 32mm particleboard screws, slightly more sparsely than plasterboards should be screwed, i.e., 20-25 cm between the screws.
I would always use particleboard screws for OSB, plywood, and particleboard because of their countersinking head.
Then I staggered the joints by one stud width when I screwed the gypsum, I used 41mm plasterboard screws for double drywall. Just because it felt a bit better, but I'm convinced it would have worked just as well with 32mm plasterboard screws. (but a dime more for a whole package, so wtf).
Regarding boards, I am wholly convinced that SP has a lot of evidence for what they claim (but I can't find the "report" since the link now goes to a general page).
Otherwise, I plan to put "anything" behind the drywall.
I will only consider price and emissions (since there are warnings about formaldehyde).
If there is a single place in the house where I need to hang something so heavy that 10mm particleboard + gypsum can't handle it, I'll have to find the studs instead or make another solution.
That's how it is; there will be very few items, if any at all, that weigh so much and need to be mounted on the wall.
I'm not spending several thousand extra kronor preparing every square centimeter of wall surface in the house for a 50" plasma TV.
(my limited experience and knowledge)
I screwed the OSB with 32mm particleboard screws, slightly more sparsely than plasterboards should be screwed, i.e., 20-25 cm between the screws.
I would always use particleboard screws for OSB, plywood, and particleboard because of their countersinking head.
Then I staggered the joints by one stud width when I screwed the gypsum, I used 41mm plasterboard screws for double drywall. Just because it felt a bit better, but I'm convinced it would have worked just as well with 32mm plasterboard screws. (but a dime more for a whole package, so wtf).
Regarding boards, I am wholly convinced that SP has a lot of evidence for what they claim (but I can't find the "report" since the link now goes to a general page).
Otherwise, I plan to put "anything" behind the drywall.
I will only consider price and emissions (since there are warnings about formaldehyde).
If there is a single place in the house where I need to hang something so heavy that 10mm particleboard + gypsum can't handle it, I'll have to find the studs instead or make another solution.
That's how it is; there will be very few items, if any at all, that weigh so much and need to be mounted on the wall.
I'm not spending several thousand extra kronor preparing every square centimeter of wall surface in the house for a 50" plasma TV.