Lifespan of different types of foam/xps

[Wallawhoa]

Sitting and looking at edge elements, etc. for the slab.

Can you expect a longer lifespan and function if you dimension for higher load?

A typical small one-story timber frame house, i.e., low load.
Considering using 100mm Xps 300 in the edge elements and the bottom layer of insulation, then 200mm s200 in the upper layer.

Or is it unnecessary?

Thanks!

 

[Wallawhoa]

What do you think?

 

[Matti_75]

Why? Serves no function whatsoever. People are building high-rises and have EPS S100 under the slab.

 

[Wallawhoa]

Why? It serves no purpose whatsoever. They build high-rise buildings and have EPS S100 under the slab

Because the creep deformation becomes less over time. Should therefore maintain its insulation capacity for a longer time?

 

[Wallawhoa]

Anyone else with comments?

 

[MrJay]

Totally unnecessary. A regular house (wooden construction I presume?) can manage just as long with EPS100 as with XPS300 in the slab. XPS is used for high point loads, something I suspect you don't have..

I have a stone house myself with extra reinforcement to handle enormous loads as if it were a high-rise, EPS100 in 3 layers, edge elements of course consist of EPS200. Nemas problemas

 

[Gabbe1]

Agree with previous writers.
The theoretical advantages that one might possibly imagine, such as better insulation value and less long-term deformation, will never be noticeable in reality.

 

[Wallawhoa]

I agree with previous writers.
The theoretical advantages one might possibly consider, such as better insulation value and less long-term deformation, will never be noticeable in reality.

Thank you for the response! Is there any advantage to placing xps at the bottom when it comes to potential moisture?

 

[Gabbe1]

No, not if you build in the recommended way, that is, with a layer (10-20 cm) of crushed stone under the insulation. And naturally, you must ensure that any incoming moisture can be drained away. XPS admittedly absorbs much less moisture compared to cellular plastic, but if built correctly, there should be no moisture load under the slab, not even on the bottom layer.

If you've come across XPS cheaply, then you might as well use it; otherwise, S100, or even S80 for that matter, will suffice excellently. Cellular plastic is probably already expensive as it is.

 

[MrJay]

Thanks for the response! Is there any advantage to putting XPS at the bottom, when it comes to potential moisture?

XPS is claimed to be better than EPS in terms of the amount of water absorbed, if you're not living in a swamp or building a pool, it doesn't matter. Moisture issues when building a house are solved by placing age-resistant plastic between layers 1 and 2 of foam plastic.

 

[Gabbe1]

XPS is said to be better than EPS in terms of the amount of water absorbed. If you don't live in a swamp or build a pool, it's irrelevant. The moisture issue when building houses is solved by placing age-resistant plastic between layers 1 and 2 of foam plastic.

Well. Any plastic between the foam is installed to prevent radon-laden air from seeping in. Regarding moisture, they try to minimize moisture load on the foam by placing a capillary-breaking layer of macadam underneath the foam.

 

[Matti_75]

XPS is said to be better than EPS in terms of the amount of water absorbed. If you don't live in a swamp or build a pool, it doesn't matter. The moisture issue when building houses is solved by placing age-resistant plastic between layers 1 and 2 of the foam.

The plastic is there to protect from ground radon.

 

[MrJay]

Poured two slabs myself this week. Plastic film at 0.2mm is intended to prevent moisture in vapor form from seeping up. The fact that it also prevents radon (if radon pipe hasn't been laid) is a bonus. There are already many threads about it, search and you shall find...

I assume you lay ground fabric and gravel if you plan to pour a concrete slab, it would be quite foolish otherwise.

 

[Wallawhoa]

Well. Any plastic between the foam insulation is placed to prevent radon-containing air from seeping in. When it comes to moisture, you try to minimize the moisture load on the foam insulation by placing a capillary-breaking layer of gravel under the foam insulation.

I am planning to have solid wood flooring on top of the slab. Should I place the foil between the foam insulation or on top of the concrete?

 

[Gabbe1]

I would have placed it on top of the concrete.