Compressive strength of Isodrän or foam plastic under foundation wall

[tlundberg]

That a "regular" edge beam is connected with a concrete slab does not affect the strength. Often nowadays, the edge beam is also insulated from the slab to reduce heat leakage.

Can you explain a bit more? I'm not quite following what you mean.

In the sketch in your initial post, it says about the concrete footing that B = Load-dependent. The seller might be able to help you with the calculation if they want to sell.

I was hoping for that too, but the seller at Beijers was not keen to help me at all. Actually a bit rude

Aren't the loads normally calculated much more roughly than you're trying to do in your calculations?

No idea. The guy at Beijer didn't dare/want to help me and referred me to a structural engineer who had to calculate it.

 

[KnockOnWood]

Can you explain a bit more? I'm not quite following what you mean.

Here you see an edge element, where the edge beam is insulated from the slab. They are only held together with rebar through the polystyrene.



Image from http://www.jackon.se/

The Beijer guy didn't dare/want to help me

I was thinking rather that you should check with someone at Isodrän.

If you check out the aforementioned Jackson, they also have some calculation examples. See the PDFs here
http://www.jackon.se/dav/07b63053f4.pdf
http://www.jackon.se/dav/1467ee3d31.pdf

 

[tlundberg]

Thank you for the links and images. I haven't seen such an edge beam before, but I'll have something similar with insulation around it. For the high line load of 40 kN/m and point load of 50 kN, they prescribe EPS500 foam. Significantly more than S200, which I have read about before being commonly used under the beam!

 

[Matti_75]

Yes, the high strength is required because the edge beam is only 152mm wide. In a normal edge beam, the pressure is distributed over a larger area.

 

[tlundberg]

Aaa, right. I will, for example, have a 400mm wide beam.

 

[Voh]

Can you explain a little more? I'm not quite following what you mean.

The foundation beam, which is in connection with the outside of the house, cools down when the outside temperature changes. This cold is conducted (thermal bridge) through the concrete into the floor/slab. You can use a so-called thermal bridge breaker to counteract this, i.e. a styrofoam edge that separates the foundation beam from the slab. The foundation beam will still be cold, but that cold is not transferred to the same extent to the slab under the house's floor since the styrofoam acts as insulation between the foundation beam and the slab. Note that you need to have thick walls to be able to use this! I don't remember the exact figures, but I think that 35-37 cm thickness is barely enough. If someone more knowledgeable can fill in the required thickness with information.

Oops, now I see that the thread is several years old. Oh well...

 

[KnockOnWood]

...
Note that you need to have thick walls to be able to use this! I don't remember the exact numbers but I think 35-37 cm thickness is on the lower side. If the required thickness is needed, someone more knowledgeable could fill in with information.
...

I have Jackons elements with a broken cold bridge myself, and the walls are a total of 387 mm including air gap and panels. You probably can't shrink it much if you want good insulation. Mine is 310 mm, which may be 50 mm more than today's "standard".

...
Oops, I just saw that the thread is several years old. Oh well...

It doesn't hurt to check a little "how it went." Was there any extension and did it become a "warm foundation," Tlundberg?

 

[Voh]

Indeed. My future house will have 200 mm walls. Timber without extra facade or additional insulation. Definitely too narrow for switches as far as I know. Or are there other/new techniques?

And interested. How did it turn out?

 

[KnockOnWood]

Indeed. My future house will have 200 mm walls. Timber without additional facade or extra insulation. Definitely too narrow for switches as far as I know. Or are there other/new techniques?
...

By the way, why would wall thickness matter so much?

 

[Voh]

By the way, why would the wall thickness be so important?

The wall should be placed on top of both the beam and the breaker. The breaker should not be placed under the living area, and the edge beam should not be placed outside the wall. So, for the wall to cover both, it must be relatively thick. If the wall thickness is to cover both the edge beam and the breaker, then the wall must be sufficiently thick.

 

[tlundberg]

Well, a little has happened. But it's going very slowly

Status here: https://www.byggahus.se/forum/socialt-projekt/220006-mitt-forsta-utbygge-tv-rum-och-sovrum-4.html

 

[KnockOnWood]

The wall should be placed on top of both the beam and the breaker. The breaker should not be placed under the living area, and the edge beam should not be located outside the wall
...

I don't understand your reasoning.
Of course, the wall's vertical studs should be on the edge beam, preferably centered, naturally.

But it doesn't really matter if the insulation between the edge beam and slab is five cm in or out inside or outside the inner surface of the wall, does it?

 

[KnockOnWood]

Yes, a little has happened. But it's going very slowly

Status here: [link]

Aha, you've had a few girls and boys to fight with along the way: Frida, Gorm, and most recently Helga.

Respect!


Here's what happened when a neighbor met Gorm. A large garage was just framed, and half the roof was laid. But then came the storm

 

[Voh]

I don't understand your reasoning.
Of course, the wall's vertical studs should be on the foundation edge beam, preferably centered naturally.

But it doesn't really matter if the insulation between the edge beam and the slab is five cm inside or outside the inner surface of the wall?

I have no personal experience of the practical difference and I'm hardly an expert. However, all of my own "research" for the upcoming build has pointed to it making a difference. All the sources I've consulted suggest that the entire thermal bridge breaker must be covered by the wall, but whether that's right or wrong isn't for me to answer, I'm just conveying other people's words.

 

[KnockOnWood]

...
All my own "research" for the upcoming construction has, however, indicated that it makes a difference. All sources I've looked at suggest that the entire thermal bridge breaker must be covered by the wall
...

OK, so let's hear what kind of research it is, and which sources you are relying on!