Porous wall - everything is falling down! Help!

[Tussilago]

Hello!

The other day our hat shelf fell down, with plug and all. And we really had long screws and proper plugs. It seems our wall is very porous. Everything that is screwed in first seems to be rock solid and then gradually becomes looser and looser and then completely comes off. I should add that it is concrete. Built in the 60s.
What can be done about this? I have received tips about chemical anchors or anchor mass? I can't remember which was best. Is this the best thing to do? Or how on earth can we get things up on the walls?

Thankful for your input.

Best regards,
Tussen

 

[Stefan N]

Is it lightweight concrete? Then there are special plugs for that.

 

[Falcen]

Everything that is screwed in seems to initially hold extremely well, only to gradually become looser and looser and eventually come undone

Just a curious question as I myself have quite porous material (light concrete, siporex or something. But siporex isn't blue concrete, right? Which the house is supposed to be built of...), what timeframe are you talking about here? Hours, weeks, years?

 

[magnusss]

Chemical anchors are guaranteed to work, but if it is siporex, it should work with the right plug (see attachment guide below)

Here is an attachment guide
http://www.clasohlson.se/Archive/ProductPDF/fastguide.pdf

Lightweight concrete anchors
http://www.vsbyggskruv.se/pdf/sid56.pdf

 

[Tussilago]

Thank you for the answers.
Regarding the time - the hat rack took about two weeks, other things have been resolved in a few months. I'm a bit worried about our new kitchen.. hope the cabinets won't come loose too...!!

Is there any disadvantage to using chemical anchors?

//Tussen

 

[kalubah]

You have to be very careful to get all the drill dust out of the drill hole and they are not exactly world-class from an environmental perspective, but if it's a very porous wall, I think you can go with it.