Hello again.
Yes, as the thread title suggests.
I've been pondering certain things over the past few months regarding construction techniques, because no matter how you look at it, it often goes like this: Yes, but it's approved to do it this way.
When I started, I worked on a few new builds where we were supposed to apply plastic both internally and externally for energy savings, I assume. These home builders also had floor joists made of pressed fiberboard that are/were approved. Kamilenski reminded me of the one-step sealed facades, where I've also been scratching my head.
Before I started, asbestos was the absolute best you could have.:S
Even in a few places now, actually in the last five years, we've built in wooden floor joists in plastic because the underfloor heating manufacturer required plastic underneath and the parquet manufacturer required plastic underneath to prevent discoloration of the floor.
But anyway, look at this thread, for example:
http://www.aftonbladet.se/bostadinredning/article136357.ab?service=print
Also this one: http://www.fokus.se/2010/03/darfor-rasar-taken/
Yes, the list can be long.
Surely there's quite a lot of construction fraud as well, but I think the majority of these errors come from the fact that it's calculated and approved. Personally, I'm not good at explaining why certain tasks are done the way they are. "My teacher" consisted of my old father, and it could go like this.
Him: Put double two nines there.
Me: But shouldn't we take double two sevens (was more readily available)
Him: No.
Me: Why not?
Him: It won't hold.
Me: Why not?
Him: But, what the hell, it won't hold. (a bit irritated)
That's how I learned durability calculation on spans.
Knock on wood, but nothing I've built without drawings has fallen down.:O
In an earlier thread, there was a discussion about placing the plastic one-third in, which to me sounds like a new experiment, as someone in the thread commented that there are many who have opinions but few who know. I can agree with that because I only wrote what I thought.
Bathrooms are on their way to becoming really good quality, but who knows, in twenty years it might go like this.
Martin Timell: But dear God, have they put membranes on the walls, oh boy, that's as carcinogenic as it gets, best to call in a decontamination company specializing in these old membranes.
But as I said, without making this thread too long.
Do we trust those who know too blindly?
Yes, as the thread title suggests.
I've been pondering certain things over the past few months regarding construction techniques, because no matter how you look at it, it often goes like this: Yes, but it's approved to do it this way.
When I started, I worked on a few new builds where we were supposed to apply plastic both internally and externally for energy savings, I assume. These home builders also had floor joists made of pressed fiberboard that are/were approved. Kamilenski reminded me of the one-step sealed facades, where I've also been scratching my head.
Before I started, asbestos was the absolute best you could have.:S
Even in a few places now, actually in the last five years, we've built in wooden floor joists in plastic because the underfloor heating manufacturer required plastic underneath and the parquet manufacturer required plastic underneath to prevent discoloration of the floor.
But anyway, look at this thread, for example:
http://www.aftonbladet.se/bostadinredning/article136357.ab?service=print
Also this one: http://www.fokus.se/2010/03/darfor-rasar-taken/
Yes, the list can be long.
Surely there's quite a lot of construction fraud as well, but I think the majority of these errors come from the fact that it's calculated and approved. Personally, I'm not good at explaining why certain tasks are done the way they are. "My teacher" consisted of my old father, and it could go like this.
Him: Put double two nines there.
Me: But shouldn't we take double two sevens (was more readily available)
Him: No.
Me: Why not?
Him: It won't hold.
Me: Why not?
Him: But, what the hell, it won't hold. (a bit irritated)
That's how I learned durability calculation on spans.
Knock on wood, but nothing I've built without drawings has fallen down.:O
In an earlier thread, there was a discussion about placing the plastic one-third in, which to me sounds like a new experiment, as someone in the thread commented that there are many who have opinions but few who know. I can agree with that because I only wrote what I thought.
Bathrooms are on their way to becoming really good quality, but who knows, in twenty years it might go like this.
Martin Timell: But dear God, have they put membranes on the walls, oh boy, that's as carcinogenic as it gets, best to call in a decontamination company specializing in these old membranes.
But as I said, without making this thread too long.
Do we trust those who know too blindly?
Honestly, I find it a bit difficult to see what you're getting at.
"Do we trust those who can too blindly?" - Should we trust those who can less instead?
Eternit was a great material until better knowledge about the dangers of its dust emerged. It's easy to say in hindsight that it was a bad idea.
I find it hard to imagine something similar happening with bathroom waterproofing. It's possible, but there is much more control and research around emissions and materials these days.
What your father taught you was definitely not any strength calculation. It was experiential values and safety through over-dimensioning.
This works great until you build something with a more advanced force distribution, for example, continuous beams, and how this affects the support loads at supports.
In many cases where there have been problems, it often boils down to economics. 7’ nails are cheaper than 9’.
"Do we trust those who can too blindly?" - Should we trust those who can less instead?
Eternit was a great material until better knowledge about the dangers of its dust emerged. It's easy to say in hindsight that it was a bad idea.
I find it hard to imagine something similar happening with bathroom waterproofing. It's possible, but there is much more control and research around emissions and materials these days.
What your father taught you was definitely not any strength calculation. It was experiential values and safety through over-dimensioning.
This works great until you build something with a more advanced force distribution, for example, continuous beams, and how this affects the support loads at supports.
In many cases where there have been problems, it often boils down to economics. 7’ nails are cheaper than 9’.
I also don't think there will be any problems with baths in the future, perhaps a bit of an abstract example of too big a question.Krawk said:
But it feels like many houses "out there" are experiments. It seems like research is being done at the property owner's expense sometimes, much to build as cheaply as possible often.
Strength in all its glory, no, it didn't give more than knowing what holds and might hold, today I know more but not so that I can tell with calculations, I worked for a while with steel and concrete constructions, so you just followed the drawings and absolutely building engineers and architects are needed, so it wasn't specifically meant in that direction my question was.
Yes, maybe too big a question, because it encompasses anyone who has made a calculation on something.
If the question is put this way instead.
Is there too much experimenting with properties "in real life"? Because if the same type of research had been going on in the car industry, I think the automotive industry would have had a few more lives on its conscience.
I would answer both.
Today, buildings are made with much smaller tolerances. That is, there is no margin left in the constructions for minor mistakes. If you take grandma's house, they didn't use a 2X6" for the floor joists. They took slow-grown logs and planed the top side. They are guaranteed overkill, but they hold no matter what you place on top. Similarly, the basement. The floor is not completely dry or moisture-proof, but it doesn't matter because it's just massive stone walls high enough. Where the wood starts, it's dry.
Today, buildings are made with much smaller tolerances. That is, there is no margin left in the constructions for minor mistakes. If you take grandma's house, they didn't use a 2X6" for the floor joists. They took slow-grown logs and planed the top side. They are guaranteed overkill, but they hold no matter what you place on top. Similarly, the basement. The floor is not completely dry or moisture-proof, but it doesn't matter because it's just massive stone walls high enough. Where the wood starts, it's dry.
Some issues:
1) There is not enough time to properly test new techniques and materials. For example, the 50-year deformation of foam plastic is calculated from significantly shorter tests. The logs in grandma's house were not chosen because "it was approved" but because it had always been done that way and it demonstrably lasted a long time.
2) Construction experts get their education in new materials and techniques from those who want to sell these new materials. (This is usually how it works with everything from electronics developers to doctors.)
Personally, I trust builders who refer to experience more than builders who constantly refer to industry organization x, approval y, and a two-day course z... To relate to TS, I have an uneasy feeling that a 2-by-9 is not as strong anymore.
1) There is not enough time to properly test new techniques and materials. For example, the 50-year deformation of foam plastic is calculated from significantly shorter tests. The logs in grandma's house were not chosen because "it was approved" but because it had always been done that way and it demonstrably lasted a long time.
2) Construction experts get their education in new materials and techniques from those who want to sell these new materials. (This is usually how it works with everything from electronics developers to doctors.)
Personally, I trust builders who refer to experience more than builders who constantly refer to industry organization x, approval y, and a two-day course z... To relate to TS, I have an uneasy feeling that a 2-by-9 is not as strong anymore.