Laying woolen glass / rock under slate without rain?

[dedeleco]

What is the difference with plamanu:
https://www.econologie.com/forums/post233013.html#233013

?????

After some time, a few gusts of wind, we will have the very usual sag, even with a beautiful windscreen or vapor barrier:

[Obamot]

Bein woui ....................... I answered "In the given configuration ...."

Yes and no, because if it is not posed rique-raque to the economy (it must be compressed / forced a little) it lasts well twenty years and beyond (hack had given the ratio of how much ... min 15%, it seems to me ...). What a difference? There is no convection if the air does not circulate / more! There, the nuance ....

Other than that, I have already said what I prefer personally.

[dedeleco]

The air circulates without convection, with the winds which make large variations in pressure, 20 to 30 millibars easily, which gives a force of 200Kgp / m2 to 300KgP / m2, which makes everything move and can open holes, after a few good gusts of wind !!!

The water vapor circulates, crosses and condenses on the cold surfaces which then wet the insulation.

Even if the vapor barrier does not allow anything to pass into vapor, the air of the day, still hot and humid under the tiles which have become cold at night, will condense its water vapor on the slates or under the umbrella and wet the insulation, for a long time.

So we can have this type of cowery very real and rarely considered!

[Obamot]

... but completely: the air circulates, even more than you say.

I also wanted to post well before, this photo of the last site where I went:



We see that the air can pass through many places, and even in recent constructions (the concrete had taken there was not very long!) In particular by the technical sheaths, the sheaths of the electric cables ... and especially by the poor workmanship that we have to flush out during site visits:




... and there, if you see the huge mistakes, with this concrete wolf jump:



Big concern: once the finishes are finished, we sometimes don't know how to locate the problem! In comparison, in framework it is much more visible and easily controllable ...

Because overall, the pressure you give in millibars, would concern a passive house or extremely well done. Other constructions are too often colanders, there you dream ...

[dedeleco]

the pressure that you give in millibars, would concern a passive house or extremely well made. Other constructions are too often colanders, there you dream ...

Yet it is the reality experienced, by me for example.

In a rapid gale, a whirlwind less than a second, the air does not have time to circulate, even in large holes, and such pressure variations are easily reached, tearing off the collages, and even the heavy tiles sometimes.

I thus had a chimney cap, however wide open, like a colander with enormous holes on all sides, torn off which fell back and broke the roof.
Another time a hole of one m2 in the tiled roof which however let the air pass, like colanders.

With vortices, small tornadoes, we have beautiful variations in pressure, especially depressions.

It is rare, very short, the second, but destructive, even vortices with classic winds at 70 km / h.

[Obamot]

My mistake. I understood your data from 200Kgp / m2 to 300KgP / m2 ...

What I meant to say is that it takes a lot less ...! And I add that it depends on the size of the gap in the insulation, because of the air draw effect: the smaller it is, the more the pressure can increase and the more the calorie loss can be radical ...

But that's when there is ad hoc pressure. Otherwise, almost nothing happens.

Insulation problems are devious