Does 21 mm paneling support 400 mm insulation?

[cust3000]

Doesn't add up. 33 kg/m3 becomes 330 N/m3, becomes 33N/m2 at 10 cm. At 40 cm it becomes 4*33=132 N/m2 or about 13 kg/m2 at 400 mm insulation.

oh, what did I write then?

1.46N/m2=14.308kg

so you're wrong and then 1N is not 10kg but 9.8kg. then it’s probably not exactly 1.46N/m'2/400mm with that density the insulation has, but I just did a quick estimation.

 

[hokanp]

1.46N/m2 = 0.146 kg/m2 and nothing else. If you don't know the units then don't bother.

http://sv.wikipedia.org/wiki/Newton_(enhet)

 

[cust3000]

1.46N/m2 = 0.146 kg/m2 and nothing else. if you don't know units, refrain.

[link])

The force (F) 1 newton is the force that gives the mass 1 (m) kg the acceleration 1m/s2.

The force affecting the mass 1 kg at the Earth's surface is given by

F = mg = m*9.81

and there's no need to have an unpleasant tone in your posts, REFRAIN from writing then!
... and by the way, Wikipedia is far from a source one should rely on when anyone can write without the source being verified...

 

[hokanp]

Now it's the case that units are my work, and I see far too many mistakes from people who think they know. Especially when it comes to structural analysis, like the pictures you showed. If you don't have the knowledge, THEN DON'T TRY. It can go terribly wrong if you continue to give answers when the error is off by a factor of 100!

 

[BigGitt]

Excuse me?
Does it hold for 285mm at 45 degrees?

 

[hokanp]

Excuse me?
Will it hold for 285mm at 45 degrees?

Yes, it holds with råspont and much more as well. It resulted in a deflection of about 50 my. Turn the question around. If you walk on a roof with råspont, does it hold?
Here, the load is much higher since you have 2 feet and their small area that transfers pressure to the råspont, which is a bigger strain than your insulation.

 

[BigGitt]

Yes, it supports with råspont and much more too. There was a deflection of about 50 my. Turn the question around. If you walk on a roof with råspont, does it hold? Here the load is much higher since you have 2 feet and their small area that transfers the pressure to the råspont, which is a greater strain than your insulation.

Yes! You're right! Thank you so much!

 

[cust3000]

Now the thing is that units are my job and I see far too many mistakes by people who think they know what they're doing.
Especially when it comes to structural analysis as you showed in the pictures. If you don't have the knowledge, THEN DON'T DO IT. It can end up disastrously if you continue to give answers when the error is off by a factor of 100!

In Newton's terms, 1 kilopond is exactly 9.80665 m/s². This numerical value was established in 1901 by the 3rd General Conference on Weights and Measures and referred to locations at 45° latitude. A more precise value for arbitrary latitude was defined in 1930 using a formula based on the earth being a homogeneous rotational ellipsoid, see the International Gravity Formula. For a location in Sweden with unspecified latitude, one should use 9.82 m/s².

But I made a mistake, which was a careless error, I reversed the factor.

I have nothing more to say.....

 

[hokanp]

Give in ..
N= kp old designation = kgm/s². i.e. how the earth's gravitational acceleration g affects a mass. This varies between 9.80 - 9.84 depending on the location where one is situated and its distance to the earth's center.

 

[cust3000]

Give it a rest...
N = kp old designation = kgm/s2. i.e., how the Earth's gravitational acceleration g affects a mass. This varies between 9.80 - 9.84 depending on the location and its distance to the Earth's center.

9.8 and 9.82 otherwise it was correct, "unit worker"
You say factor 10 which is wrong!
Give it a rest!

 

[hokanp]

We use a factor of 10 when making our calculations to compensate for any errors that arise due to where one is located on Earth. If I use 10 instead of 9.8*, it results in an error of 2% and not 100000% as your attempt produced.

 

[cust3000]

1.46N/m2 = 0.146 kg/m2 and nothing else. if you don't know units then refrain.

[link]

There you go, now it turned out that you were wrong......

 

[hokanp]

I am not wrong. I am using a deliberate mistake that I also include in my evaluation of the result. A result that I understand.

 

[cust3000]

I am not wrong. I am using a deliberate error that I also include in my evaluation of the result. A result that I understand. You shouldn't talk about social competence, you completely lack it.

2% error in a precise structural analysis on a 2000m^2 roof, do you consider that "ok"?
What do you work with more specifically?

 

[Marlen Eskilsson]

You are welcome to determine who is right and who is wrong, but refrain from personal attacks!