Why does everyone use OSB behind drywall?

[Nytt_användarnamn_2024_12]

Yes, it makes an extreme difference with an open and a closed door. If it's open, the fire gases spread very quickly, if it's closed, the spread is significantly delayed.

You're completely wrong, hope you don't work with fire🤓🙈😀

 

[Rabbithole]

It was Daniel's claim that a regular interior door stops a lot, which is a completely crazy claim...

“Yes, it stops a lot of smoke.”
He wrote in post #255 until this is backed up with facts, it is pointless to discuss with amateurs.

You can't see in the film which door they enter through, but in that room there is a plain door that looks relatively intact. One of those smooth 70s interior doors with veneer.

It's fairly obvious that a closed interior door slows both the smoke, available oxygen, and the fire progression more than an open door. The real question is just how long.

Any attempts to belittle the opponent in the debate only erode one's own credibility. Post some proof or evidence of how it actually stands instead.

 

[Slarvpellen]

In the event of a full fire, there's no one there to close a door, so, of course, it's a matter of more than seconds. It's certainly a delay of many minutes to "full fire" and total spread of smoke gases.

That is, there was nothing wrong with what was written earlier in the thread.

It goes without saying that a poorly sealed junk door significantly reduces the spread of smoke gases as long as the door is still there. So, it's considerably better to close any door than not to do it.
Then one can discuss how long a fire door vs a junk door continues to exist, but that mostly becomes a hypothetical opinion-economy question!
Actually, an uninteresting side track in the thread.

Regarding the original question, I would say the whole discussion was considerably more valid when OSB cost 100 bucks a sheet, now you have to think about it more.
It's obvious over the years in various threads here that there's no problem attaching almost anything to single or double drywall if you want to. Nowadays, there are plugs and similar that more or less handle everything they need to handle!
A lot of it is probably more about preference and taste.
What experience do you want when you knock on the wall?
Do you need to consider flexibility? (Too weak studs in the wall?) Is that something that bothers you?
Do you have extremely small rooms? Does every 10mm matter for the space?
And so on...

 

[Nytt_användarnamn_2024_12]

Generally, almost all standard interior doors are unclassified when it comes to fire resistance in our small houses. If they are classified, they are not made of masonite or just plywood but require non-combustible materials, as well as intumescent seals and a smaller gap under the threshold than regular interior doors.

A fire-rated door is a door that is specifically designed to withstand the spread of fire. These doors are usually made from materials like metal or glass, which are more resistant to heat than wood. Fire-rated doors also have special seals and gaskets that help prevent smoke and flames from passing through gaps.

Regular interior doors, on the other hand, are not necessarily designed with fire safety in mind. This means they can be made from materials like wood, which can easily catch fire. Standard interior doors typically don't have the same type of seal or gasket that a fire-rated door would have.

https://24stockholm.se/brandklassade-innerdorrar-skillnaderna-jamfort-med-vanliga-innerdorrar/

 

[Slarvpellen]

You can think that, but show facts or a construction description that supports your claim that an unclassified door stops lots of fire gases.
A completely incorrect statement by Daniel.

That's mostly semantics.
A door must be completely sealed to stop the permeability of gases.
A non-sealed door will only reduce the amount of gases that penetrate, but it can do that quite well.
Then it's ANOTHER discussion on how long the door (or wall) continues to exist.
And which applications this applies to, hardly a normal house that has particularly high demands on special fire safety.

 

[Nytt_användarnamn_2024_12]

That's mostly semantics.
A door must be completely sealed to stop the permeability of gases.
A non-sealed door will only reduce the amount of gases that penetrate, but it can do that quite well.
Then there's another discussion on how long the door (or wall) continues to exist.
And which applications this applies to, hardly a normal house that has particularly high demands on special fire safety.

It is the non-sealed frame and door leaf connection that allows fire gases to pass through right at the beginning of a fire.

 

[Tomture61]

😂 How on earth did a thread that started 12 years ago about OSB in walls end up being about whether doors should be closed/open during a fire 🤔

 

[Nytt_användarnamn_2024_12]

😂How on earth has a thread that started 12 years ago about OSB in walls
turned into discussing whether doors should be closed/open during a fire 🤔

You can ask Daniel who wrote post #251 about it, a completely incorrect statement😀

 

[anders07]

It is the leaky frame and door leaf connection that lets the smoke gases through right at the start of a fire..

I am a trained smoke diver and one of the first things you learn is to close all doors behind you.
This is to prevent spreading and drafts that give the fire more oxygen.
Smoke gases leaking through a door frame are the least of your worries if you are trapped in a burning house.

 

[MathiasS]

It goes without saying that a drafty lousy door significantly reduces the spread of smoke gases, as long as the door remains. So it's considerably better to close any door than not to do so.

Exactly. That's why I question why it's being challenged.

 

[Nytt_användarnamn_2024_12]

It's fairly obvious that a closed interior door slows down both fire gases, available oxygen, and the fire's progress more than an open door. The question is really just for how long.

Not particularly long since there is no sealing between the frame and the door leaf, and in modern houses, there's a ventilated threshold, meaning completely open underneath.
If these doors resisted fire and fire gases, they would be classified.
Which most interior doors in small houses are not.

Any attempt to disparage an opponent in the debate only erodes your own credibility. Post some proof or basis for how things actually are instead.

It's not about disparaging, but that he makes a claim without any evidence. I've asked for facts several times but received none, only short incorrect assertions.
So the person in question has simply said something they can't back up with facts, so it's not really me who should disprove it.
But now I've done so, and the person in question has not provided anything to support his claim, so the case is clear 😊

 

[Tomture61]

Have checked prices on various materials behind drywall.
Clearly double drywall is the cheapest, however, OSB is still the second cheapest building board per m2.

In my own house from 2008, I have single drywall on all the exterior walls downstairs.
I regret that choice so much, you can see how wavy the wall is + lousy soundproofing.
Window sills are foil-coated MDF that is glued, so not easy/cheap to improve.

 

[Krille4]

Yes, you buy yourself the time to get out of the house, but it doesn't stop a fire.
Can you show me where in a fire description or construction description a standard interior door is considered fire protection?

So is the time negligible or does it buy you the time to get out of the house?

If the house is fully ablaze, it probably won't stop the fire, but fires don't often start with a fully ablaze house; they begin on a much smaller scale. In the "worst case," you buy yourself time to get away, and the fire brigade gets a bit more time to extinguish the fire. In the best case, you impede the oxygen supply so much that the fire doesn't spread or even goes out.

/Krille

 

[Nytt_användarnamn_2024_12]

I am a trained smoke diver and one of the first things you learn is to close all doors behind you.
It's to prevent spreading and drafts that give the fire more oxygen.
Smoke gases leaking in through a door frame are the least of your concerns if you're trapped in a burning house.

Read the thread today, it wasn't about being trapped in the house.
Rather, it was about whether a regular interior door stops a fire progression.
Would love to receive facts about whether a regular interior door stops smoke in large amounts as claimed in post #255?

So, is the time negligible or does it buy you some time to get out of the residence?

If the house is fully engulfed, it probably won't stop the fire, but fires don't often start with a fully engulfed house; they begin on a much smaller scale. In the "worst case," it buys you time to get away and gives the fire department a bit more time to extinguish the fire. In the best case, you hinder the oxygen supply enough that the fire doesn't spread or even extinguishes.

/Krille

As I've previously written, it was his claim about it stopping "large amounts" that is incorrect, nothing else.

Bring forward facts if you also agree 😊

 

[ArneTW]

Not very long since there is no seal between the frame and the door leaf, and in modern houses, there is a ventilated threshold, i.e., completely open underneath..
If these doors could resist fire and smoke, they would be classified..
Which most interior doors in small houses are not..

It's not about belittling, but he is making a claim without any evidence. I have asked for facts several times but haven't received any, only short incorrect claims..
So the person in question has simply said something they can't back up with facts, so it's not really my job to disprove.
But now I've done it, and the person in question hasn't provided anything to support his claim, so the matter is clear😊

He doesn't need to support his claim because it's trivially obvious that a building with all doors closed will experience a slower fire progression regardless of the quality or class of the door...

Your claim requires a bit more information/evidence.

/ATW