I live in an apartment built in the 1940s and I'm trying to secure some tracks for an Elfa shelving system. The wall in question is adjacent to the house's exterior wall. Of course, I want the screws to hold firmly and the shelf to be properly fixed, so that everything doesn't come crashing down one day.
The problem is that the wall first has a very porous layer of some kind of plaster, but my very limited experience with plaster walls tells me that this is even more porous than usual. It's quite easy to hand screw into the wall through the first layer.
The second layer seems to be an air gap. When you screw through the first layer, you kind of "fall into" the wall, much like when you drill into a drywall; it just goes "poof" and you're through.
The third layer is what I would assume is brick. Or at least a much harder material, which I have to assume is what the house's exterior wall is made of.
If you tap the wall, it sounds hollow. It doesn't have at all the solid feel I've experienced with other walls adjacent to an exterior wall.
I've tried screwing directly into the wall, but it feels very loose. I've also tried drilling 6 mm and then using Elfa's own 8 mm plugs, but the screw doesn't grip in the plug and just spins.
I assume this is a relatively common problem, but I've never encountered it. How do I best secure the tracks? I assume I need to get a grip in the brick or whatever it is at the back? Do I need longer plugs and screws than Elfa's own then? Or should I use any special method?
The problem is that the wall first has a very porous layer of some kind of plaster, but my very limited experience with plaster walls tells me that this is even more porous than usual. It's quite easy to hand screw into the wall through the first layer.
The second layer seems to be an air gap. When you screw through the first layer, you kind of "fall into" the wall, much like when you drill into a drywall; it just goes "poof" and you're through.
The third layer is what I would assume is brick. Or at least a much harder material, which I have to assume is what the house's exterior wall is made of.
If you tap the wall, it sounds hollow. It doesn't have at all the solid feel I've experienced with other walls adjacent to an exterior wall.
I've tried screwing directly into the wall, but it feels very loose. I've also tried drilling 6 mm and then using Elfa's own 8 mm plugs, but the screw doesn't grip in the plug and just spins.
I assume this is a relatively common problem, but I've never encountered it. How do I best secure the tracks? I assume I need to get a grip in the brick or whatever it is at the back? Do I need longer plugs and screws than Elfa's own then? Or should I use any special method?
In the 40s, during the war and a little after, there was a shortage of many things in Sweden and they built accordingly, but I would guess it is some form of masonry/brick that has then been covered with plaster.
To make the plaster stick, a kind of mat made of wire and reed was often attached to the brick.
You need to get into the brick, or whatever type of masonry it is, and the entire plug needs to go into the stone. Then a longer screw that goes the entire length of the plug plus through the reed mat and plaster to your track.
To make the plaster stick, a kind of mat made of wire and reed was often attached to the brick.
You need to get into the brick, or whatever type of masonry it is, and the entire plug needs to go into the stone. Then a longer screw that goes the entire length of the plug plus through the reed mat and plaster to your track.
Sounds reasonable! I measured the hole to the brick (or whatever it is) and it seems to be a little more than 5 cm up to it.T Testarn said:
I also saw that there is something called facade plug, such as Fischer DuoXpand which is 8x100 mm or 8x120 mm. Could that be something? I'm a bit unsure how deep you ideally want the plug to fasten in the brick. But in theory, I should be able to drill 100 or 120 mm straight into the brick and fasten with that plug?
You're not screwing into the mortar between the bricks then? Old render can often be brushed away once the "film" is destroyed, which it obviously is when you screw into it.
Hard to say, but I have screwed in a far less critical item into another wall that is also against the outer wall and experienced the same thing there. And I used four different holes, so I don't think it's a matter of reaching the mortar.G grovspacklarn said:
In any case, the first layer is, as mentioned, extremely porous, and if you knock on the wall you might think it's a drywall almost. So it's quite obvious that it's a porous, fairly thick layer and then a little air and then suddenly much harder.
Fast plaster adheres well to masonry so that idea falls through..
Is TS sure that there isn't a wooden wall inside where the reed mat is used as a plaster carrier?
Reed mat was also used as a fire protection measure on wooden walls that needed it..
Also called kloasongvägg:
https://sv.wikipedia.org/wiki/Kloasongvägg
Is TS sure that there isn't a wooden wall inside where the reed mat is used as a plaster carrier?
Reed mat was also used as a fire protection measure on wooden walls that needed it..
Also called kloasongvägg:
https://sv.wikipedia.org/wiki/Kloasongvägg
If there is brick or other compact stones behind the plaster and reed mat, the included plugs from ELFA should suffice. Just make sure that the plugs go completely into the stone. They will then not be visible from the surface of the wall.
That could very well be the case. I know very little about different materials, so I've mostly been going on gut feeling and guessing.J Jansson69 said:
But does it matter for the problem of attaching to the brick furthest in? Or do you mean that in that case one should be able to attach to the first layer if it is wood?
you need to go into the brickT tobiasger said:
If it's as I believe, there's a plank wall behind the plaster, which you can easily check by screwing in a wood screw through the plaster to see if it holds.T tobiasger said:
Here is a link about these walls:
https://www.byggahus.se/forum/threads/hur-hantera-vaeggar-med-vassmatta-och-puts.510776/
Suspected that. But then it should work to drill approximately 100 mm in and then use the plug I linked above? Or do you want the plug to go in more than 5 cm into the brick? I have no idea how deep the brick is, you definitely don't want to accidentally drill straight through the outer wall. But I assume it's much deeper than that.G grovspacklarn said:
You can tap the plug through the plaster. The plug does little, if any, benefit in the plaster.T tobiasger said:
You can probably assume that the brick is at least 10 cm thick.
First check if you have wood behind the plaster!T tobiasger said:Suspected that. But then it should work to drill about 100 mm in and then use the plug I linked above? Or do you want the plug to go more than 5 cm into the brick? I have no idea how deep the brick is, you'd prefer not to accidentally drill straight through the outer wall. But I assume that's much deeper than that.