ᐅ Reuse Styrodur 3035 CS insulation from a demolition?

Hello everyone,

Today, to our surprise, we discovered a large pile of used extruded polystyrene (XPS) insulation boards on our property. I’m a bit puzzled… I assume these are intended for the foundation insulation. It looks somewhat like they might be from a building demolition. Is it acceptable to reuse them like this? Some of the boards are quite damaged… On the other hand, if they fully serve their purpose, it would also prevent new production because of us.

Thanks for your input.
Good luck!

Just spoke again with the construction manager – he said that the boards do indeed come from a demolition but (except for the heavily damaged ones) can still be used. He mentioned that these are glued with construction foam – is that normal?
A second topic was the strip footings – instead of the bond beams, steel fiber reinforced concrete was used – is that acceptable?

BeHaElJa schrieb:

Just spoke again with the site manager – he said that the panels do indeed come from a demolition but (except for the very damaged ones) can still be used. He mentioned they are glued together with construction foam – is that normal?

Why not? It’s better than disposing of the material at a higher cost; it should also save you some money.

BeHaElJa schrieb:

Another topic was the strip foundations – instead of a ring beam, steel fiber reinforced concrete was used – is that okay?

You mean the slab foundation, right?

Regards, Bauexperte

Don’t you have an expert on board? Otherwise, why do you always ask such things here?

I don’t mean this in a bad way, but some of these are basic questions — usually asked after something has already happened.

I would reuse the panels as well — but why would they be glued together with construction foam? To each other or to the surface? Both would be wrong.

Thank you for your responses,

We have received a quote from the expert and are still considering it, although he would only come in afterwards – no, I was referring to the strip foundations all around.
I almost assume he has already included the slab foundations in the price – I even know the project they came from – it had to be demolished because they significantly exceeded the building permit / planning permission boundaries.

Good evening,

here we are again with the topic of "dangerous half-knowledge"...

You should follow Lexmaul’s advice... even if sometimes he can be a bit irritating, this time he is absolutely right regarding the expert! The expert will also explain to you why your builder wants to glue the Styrodur boards as a sub-slab insulation... will... must.

A ring beam has nothing to do with strip foundations; strip foundations are always made of concrete – what else would they be made of? An alternative would be a load-bearing slab on ground; however, your structural engineer has apparently ruled this out, otherwise strip foundations would not have been planned.

Best regards, Bauexperte