I plan to build bathroom walls and have the kitchen on the other side of the wall. Is it possible to achieve a sufficiently strong attachment of kitchen cabinets to a 75mm leca wall or possibly a 100mm siporex wall?
How would one best do it in that case?
How would one best do it in that case?
For heaven's sake, no plastic plugs and screws.
You have two forces affecting the attachment. One is a shear force from the weight, acting parallel to the wall. The other is a moment from the weight acting half the cabinet's depth out from the wall, turning into a pulling force. It's the latter that typically causes the cabinets to collapse over time. Do this instead.
Buy M6-M8 threaded rod + washers + lock nuts and some cement (or light concrete adhesive). Cut the rod into pieces. The length should be = wall thickness + the thickness of the cabinet's back panel + the thickness of the slat at the top of the cabinet, which is normally fastened through with screws + an additional centimeter for the washer and lock nut. Drill 8-10 mm holes through the wall. Be careful to align them with the pre-drilled holes in the slat at the top of the cabinet. Mix cement and water to a thick slurry. Fill the holes with the cement slurry (a paper wad at the back prevents it from leaking out). Dip the threaded rod pieces in the slurry and insert them into the holes until the back edge is nearly flush with the wall surface. Let it cure for three days. Hang up the cabinets and secure with washer and lock nut.
__________________
The Builder
You have two forces affecting the attachment. One is a shear force from the weight, acting parallel to the wall. The other is a moment from the weight acting half the cabinet's depth out from the wall, turning into a pulling force. It's the latter that typically causes the cabinets to collapse over time. Do this instead.
Buy M6-M8 threaded rod + washers + lock nuts and some cement (or light concrete adhesive). Cut the rod into pieces. The length should be = wall thickness + the thickness of the cabinet's back panel + the thickness of the slat at the top of the cabinet, which is normally fastened through with screws + an additional centimeter for the washer and lock nut. Drill 8-10 mm holes through the wall. Be careful to align them with the pre-drilled holes in the slat at the top of the cabinet. Mix cement and water to a thick slurry. Fill the holes with the cement slurry (a paper wad at the back prevents it from leaking out). Dip the threaded rod pieces in the slurry and insert them into the holes until the back edge is nearly flush with the wall surface. Let it cure for three days. Hang up the cabinets and secure with washer and lock nut.
__________________
The Builder
At Essve's technical support, you get excellent help and I actually see no reason not to trust these guys.imported_Byggaren said:
But, well, we'll see... the cabinets have been there for almost a year now and should probably fall down soon....
There are special plugs for lightweight concrete walls, a bit larger than regular ones and with wings. They work excellently in most cases. Otherwise, you can do as the builder suggests, possibly with special anchor mass instead of the cement mix if you prefer. However, I agree with Mathias that it should work with regular plugs as well, but you must be careful that the holes do not become too large when drilling them. Possibly use a drill bit one millimeter smaller than you would for concrete.
Yes, what I mean is rather that the hole tends to become a little larger than the drill bit in porous materials, and that smaller steel might be needed to get the right size of the hole. But this you'll have to try, if it turns out that you have to force the plug in too much, then you need to drill a bit more.
Ok, thanks. Let's see how I do it, but it seems like a bit too much work with threaded rods if plugs and screws are enough. However, our kitchen cabinets have had a tendency to become very well filled for some reason, so maybe the threaded rod is justified after all...
Self-builder
· Stockholm
· 8 592 posts
I have installed both kitchen cabinets and a TV mount (for 24 kg) in lightweight concrete walls at home.
Used anchors (plastic anchors) and screws. For the kitchen, I first attached a 45x95 frame (plus one at the bottom as support) and then screwed the cabinets into it.
Works perfectly— the kitchen has been up since 2003 without any sign of wobbling—about 50% is mounted on a load-bearing concrete wall there, so that helps a bit
As jon_h says, drill holes in lightweight concrete tend to be somewhat larger than in less porous materials, so if you have a 5mm anchor, you often can use a 4.5 or 4 mm drill bit and then hammer in the anchor, so it fits a bit tighter.
You could probably also use rods dipped in concrete mix—but that seems a bit cumbersome.
Regarding the forces, it's essentially only a force straight down (gravity), unless you're climbing and pulling on the cabinets outward, but that's relatively rare!?
The problem is that you create a pivot that the cabinets can rotate around, leading to a pulling force at the top. The trick is, of course, to minimize this by setting the cabinets straight, for example, by having a frame both at the top and bottom that are equally thick.
Then the pulling force will be minimal, and the only torque you get (which creates the "pulling force") is what's equivalent to the cabinet's thickness times the weight. And I've never had any problem with any cabinets showing any tendency to give way—there's more friction than you'd think when you screw a thick screw into the anchor—try pulling one out sometime. A crowbar and a heck of a lot of force are required if it's set correctly, and that gives quite a large torque compared to a kitchen cabinet's 30 cm and a bunch of plates, plus, of course, you can use more than one screw
/K
Used anchors (plastic anchors) and screws. For the kitchen, I first attached a 45x95 frame (plus one at the bottom as support) and then screwed the cabinets into it.
Works perfectly— the kitchen has been up since 2003 without any sign of wobbling—about 50% is mounted on a load-bearing concrete wall there, so that helps a bit
As jon_h says, drill holes in lightweight concrete tend to be somewhat larger than in less porous materials, so if you have a 5mm anchor, you often can use a 4.5 or 4 mm drill bit and then hammer in the anchor, so it fits a bit tighter.
You could probably also use rods dipped in concrete mix—but that seems a bit cumbersome.
Regarding the forces, it's essentially only a force straight down (gravity), unless you're climbing and pulling on the cabinets outward, but that's relatively rare!?
The problem is that you create a pivot that the cabinets can rotate around, leading to a pulling force at the top. The trick is, of course, to minimize this by setting the cabinets straight, for example, by having a frame both at the top and bottom that are equally thick.
Then the pulling force will be minimal, and the only torque you get (which creates the "pulling force") is what's equivalent to the cabinet's thickness times the weight. And I've never had any problem with any cabinets showing any tendency to give way—there's more friction than you'd think when you screw a thick screw into the anchor—try pulling one out sometime. A crowbar and a heck of a lot of force are required if it's set correctly, and that gives quite a large torque compared to a kitchen cabinet's 30 cm and a bunch of plates, plus, of course, you can use more than one screw
/K
"When it comes to forces, it's really just a force straight down (gravity), unless you're climbing and pulling on the cabinets outward, but that's relatively rare, isn't it?"
Not true!
There is always a component straight out from the wall at the top of the cabinets due to the moment.
Not true!
There is always a component straight out from the wall at the top of the cabinets due to the moment.
The problem is not only whether the plug is properly set or not, but in which material it sits. Regardless of the material in the plug (plastic or nylon), the technique relies on the plug expanding for the screwed screw and creating clamping force/friction against the surrounding material. If this is in lightweight concrete, which consists of thin and quite porous walls around air-filled cells, pressure is applied to the walls between the cells during expansion. If that pressure becomes too great, it causes crushing in the cell walls between the air-filled voids and friction then becomes zero.klaskarlsson said:... there is more friction than you think when you screw a thick screw into the plug - try pulling one out sometime. A crowbar and a heck of a lot of force are required if it's properly set, and it provides quite a large torque compared to a kitchen cabinet's 30 cm and a load of plates, plus you can of course have more than one screw
/K
Furthermore, there is a risk of cold drawing in the plastic for plastic plugs (but not nylon plugs) if it is a plug of less scrutinized quality brand. Meaning that the screw stretches out the plastic under axial load = pull-out force. And the plug can very well remain in the hole when the screw is fully withdrawn. (This is among other reasons why plastic plugs should not be used for installing suspended ceilings in escape routes, and it has nothing to do with people needing to exit the building in an emergency, but rather with fire personnel, etc., needing to enter without risking having it fall on their heads.)
Regarding the pull-out force, it's easy to calculate how much force is needed to avoid cabinet tipping. Half the depth of the cabinet is the moment arm. The total weight of the cabinet plus what will be in it is the gravity force. Multiply the moment arm by the gravity force. Then compare it to a moment arm that is the length from the bottom of the cabinet to the attachment point. That is, divide the first obtained result by the last length and you will get how much force is needed to prevent the cabinet from tipping outward due to the weight. Then I think you'll skip the plastic plug in favor of a better attachment
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Byggaren
Self-builder
· Stockholm
· 8 592 posts
Which I also wrote further down - but that moment depends on the cabinet depth (lever arm) and the force caused by the weight due to gravityanaitis said:
/K
Self-builder
· Stockholm
· 8 592 posts
imported_byggaren:
As mentioned, it depends a bit on quality and screws as well.
I have used both 8mm plugs + sturdy screws, as well as nail plugs (6-8mm thick with about 6-8 cm length). Both work great in my lightweight concrete walls at least, but if you want to be sure, you can of course go with threaded rod and concrete grout, just wanted to say that plugs/nail plugs work for me at least.
/K
As mentioned, it depends a bit on quality and screws as well.
I have used both 8mm plugs + sturdy screws, as well as nail plugs (6-8mm thick with about 6-8 cm length). Both work great in my lightweight concrete walls at least, but if you want to be sure, you can of course go with threaded rod and concrete grout, just wanted to say that plugs/nail plugs work for me at least.
/K
Regarding hanging kitchens in aerated concrete, I have found a plug that is unbeatable.
I have three smaller apartment buildings built with Ytong stone in load-bearing walls and Siporex planks in non-load-bearing partition walls.
In all kitchens and other heavier fastenings, I use a plug from Fischer called the GB 8 aerated concrete plug. It is incredibly good and looks like this. http://www.fischersverige.se/befestigung/expert/GENERAL/fischerGB.pdf
I have three smaller apartment buildings built with Ytong stone in load-bearing walls and Siporex planks in non-load-bearing partition walls.
In all kitchens and other heavier fastenings, I use a plug from Fischer called the GB 8 aerated concrete plug. It is incredibly good and looks like this. http://www.fischersverige.se/befestigung/expert/GENERAL/fischerGB.pdf