Plug won't adhere to lightweight concrete

[ZipLock]

What is the dimension of the screws? For coarser dimensions, lättbetongskruv works very well.

 

[kanonkula]

Hello!

I live in an aerated concrete house and have just installed a heavy patio door with Essve's triangular aerated concrete plug. Never doing that again. Crap plugs.
Had to redo it and put some mortar in the holes and redo, despite neat smaller holes. The plug doesn't like being screwed in and out. Tomorrow the next door goes up so I fixed some other things...

My tip is either a metal aerated concrete anchor or a special plug with wings as per the picture.

The plug with wings is available at Bauhaus from Stabilt and 4 pieces cost about 35kr compared to Fisher's equivalent which costs 90kr.

The aerated concrete anchors are from FAST and purchased from Velltra, costing 90kr for 40 pieces.
Quite a price difference.

I did a test, screwed these into the wall without torque back and forth.
The plug with wings almost made the wall crack, that's how firm it sets.
Then I tried taking pliers and pulled with all my might. After quite an effort, I managed to get out the aerated concrete anchor, but I had to really struggle.
The plug with wings is still in, can't get it out.

Essve's aerated concrete plug is no problem to pull out despite small neat holes.

The advantage of the aerated concrete anchor is that you can get the plug more exactly where you want it. Not as easy with the plug with wings, which tends to catch on a bit due to resistance when you drive it into the hole. The anchor also does not move in the hole in the same way as the plug with wings, even though you can never get the plug out. But it allows for movement. Note: I had driven the screw in and out almost to the wall breaking point without torque, of course, that affected it. But the anchor was not affected in the same way despite the same procedure.

Thus, I will continue to use the anchors instead, significantly cheaper and worked great.
For really heavy items, a combo with plug with wings and anchor can be good.
Tomorrow it will be a combo. I also fill the holes with cement in a tube before driving in the plug/anchor.

For putting up shelving systems and similar, it will be anchors moving forward. Heavy glass doors, sliding sections, etc. a combo is preferable.

Used adjufix for doors and windows.
You expand the adjufix from the frame, level the entire frame, then drill the adjufix and plug and screw or use their aerated concrete screw directly.
Works great.
Most times it works well to drive an aerated concrete screw directly into aerated concrete, just don't overtighten.

 

[Kultypjämt]

Used adjufix for doors and windows.
You expand the adjufix from the frame, level the entire frame, then drill the adjufix and plug and screw or use their aerated concrete screw directly in.
Works super well.
Most of the time it works well to use an aerated concrete screw directly in aerated concrete, as long as you don't over-tighten

That's what I use

 

[Sko66]

I'm reviving the thread again and hoping you have some good advice to offer
I installed two IKEA shelves in my daughter's apartment some time ago. These are the kind with no support brackets underneath, just thicker shelf boards that jut out from the wall.
Each "bracket" (two per shelf) was fastened with four or five screws using wall plugs, but now one of the shelves has fallen down
When I drilled the plugs into the wall, I noticed it was easy to drill, and of course, I used hammer action while drilling... not good according to what I can read in the thread.
But I thought it was a solid concrete wall. The powder that came out during drilling was initially white and then red powder came out. It was probably surface rendering at first, and then there seems to be some sort of porous red material behind it. However, I didn't notice that it behaved as if it were hollow brick in the wall.

Now I need to mount the shelf again, but what kind of wall plug should I use this time? The holes have probably become somewhat larger since the plugs were torn out of the wall when the shelf fell.
Also, there is a small problem that the brackets cannot be mounted with screws that have heads too large for the shelf to slide on and lock onto the brackets again.
Longer screws can be used, but not thicker...

Do I need to fill the holes with some kind of compound first? What type of compound, if so? Or are there suitable plugs that would fit directly in the holes again but can support the shelf this time?

 

[Stefan1972]

I'm reviving the thread again, and hope you have good advice to offer
I mounted two IKEA shelves in my daughter's apartment a while ago. These are the type without any bracket supporting them from underneath, instead, they look like slightly thicker shelves that just protrude from the wall.
Each "bracket" (two per shelf) was attached with four or five screws in plugs in the wall, but now one of the shelves has fallen down
When I drilled the plugs into the wall, I noticed it was easy to drill, and of course, I used a hammer drill... not good as I can read in the thread.
But I thought it was a solid concrete wall. The powder that came out when drilling was white at first, and then red powder came out. Probably it was initially surface plaster, and then it seems to be some sort of porous red material behind. However, I didn't notice it behaving like it was hollow brick in the wall.

Now I need to remount the shelf, but what should I use for plugs this time? The holes are probably somewhat larger since the plugs were ripped out of the wall when the shelf came loose.
Then there's a small problem that you can't mount the brackets with screws with too large heads for the shelf to be able to slide on and lock again on the brackets.
Longer screws can be used, but not thicker...

Do I need to fill the holes with some compound first? What type of compound in that case? Or are there suitable plugs that should fit directly into the holes again, but that will hold up the shelf this time?

it's likely plaster and then brick, and in such a wall, traditional plugs are difficult. You need something long, probably 100-150mm long "nail plugs" so they go in a bit, and then it's almost better if you drill with an ordinary metal drill. Not carbide but a regular drill. They wear out, but the holes keep their dimensions better. And of course, no hammer drill.

 

[plåtrickard]

Avoid nail plugs at all costs... They're not even good in the box...
There are plastic plugs for hollow blocks and lightweight concrete, I guess it's hollow bricks if it was easy to drill and red dust came out.

 

[Mikael_L]

If the orange/red dust appears, it undeniably sounds like brick, and that's not too bad, because anchoring in brick isn't too difficult. But primarily, you need to penetrate deeper into the brick; you'll want to get at least 30mm deep into the brick, and preferably double that. Drilling into brick with a rotary hammer and percussion is risky, as brick can crack easily, and then the anchoring can become much weaker. A regular (poor) impact drill is actually better, with much less impact energy and less risk of cracks. But without impact can also be the trick, although sometimes it feels like it doesn't penetrate at all without impact; in such cases, I usually use impact but proceed incredibly gently and carefully.

I don't think I would have looked for a miracle plug when it comes to brick; rather, a pretty standard good-quality plastic plug would do, and then be careful to choose the right hole diameter, plug and screw diameter, and the correct screw length (and depth of the hole), checking the plug's installation instructions.

 

[Sko66]

If orange/red dust comes out, it does indeed sound like brick, and that's not so bad, because in brick, fastening is not so difficult.
But above all, you probably need to go deeper into the brick; you want to get at least 30mm deep into the brick and preferably double that.
Drilling into brick with a hammer drill is tricky; brick can easily crack, and then the fastening can become much weaker. An ordinary (poor) hammer drill is actually better, much less impact energy and less risk of cracks. But without impact may also be the trick, but sometimes it feels like it doesn't bite at all without impact, then I usually use impact but operate very gently and carefully.

I don't think I would have looked for any miracle plug when it comes to brick, but rather a fairly common plastic plug of good quality, and then be careful to choose the correct hole diameter, plug, and screw diameter, and the correct length of the screw (and depth of the hole), check the plug's installation instructions.

If orange/red dust comes out, it does indeed sound like brick, and that's not so bad, because in brick, fastening is not so difficult.
But above all, you probably need to go deeper into the brick; you want to get at least 30mm deep into the brick and preferably double that.
Drilling into brick with a hammer drill is tricky; brick can easily crack, and then the fastening can become much weaker. An ordinary (poor) hammer drill is actually better, much less impact energy and less risk of cracks. But without impact may also be the trick, but sometimes it feels like it doesn't bite at all without impact, then I usually use impact but operate very gently and carefully.

I don't think I would have looked for any miracle plug when it comes to brick, but rather a fairly common plastic plug of good quality, and then be careful to choose the correct hole diameter, plug, and screw diameter, and the correct length of the screw (and depth of the hole), check the plug's installation instructions.

Yes Mikael_L, it feels like I've followed your instructions from the beginning...
I'm not completely new to screwing things with plugs into concrete walls, so I'm careful to choose the right plug for the screw and then the right drill for the plug. I used a blue Bosch drill with impact, and drilled carefully after I noticed the wall was so soft. However, I didn't think to turn off the impact.
So in my world, I did pretty much everything right. Drilled carefully straight in without wobbling and deep enough for the plug to go in properly and a bit more so there's room for the screw. However, my perception is that real bricks are harder than in this wall.

Now, I don't know if my daughter has had a proper party in the apartment, and if they've been hanging on the shelf... the exact truth doesn't always come out, of course... but I thought the mounting would hold even for such actions considering how many screws the brackets were attached with.
But the shelf suddenly fell down by itself without any interference after about nine months... according to my daughter.

The plugs are normally not inserted further than the surface of the wall, and in this case, it was obviously not far enough for them to hold properly, especially since there's no support from the brackets going down against the wall under the shelf.
So either I'll have to deepen the holes and push the plugs in further and use longer screws, or I'll have to find some better kind of plug.

 

[Mikael_L]

If it's a thick layer of plaster, it becomes a problem, the plaster is almost never strong enough.
And if it's a thick layer, then the plug and screw must be really long to properly reach into sturdier material.
Long screws are easy, but long plugs are not quite as easy to find.

 

[richardtenggren]

Bricks usually work well without hammering, I like Bosch Multiconstruction drills. I'm using these now as I'm fixing up a part of the basement, where we have concrete hollow blocks and Leca.

Do you have the right screw length in relation to the plug?

 

[halj]

Can highly recommend lightweight concrete screws, should work for brick as well. They hold as well as possible in a porous material. Available in lengths from 60 to probably 600mm, but around 100 will surely be more than enough!

 

[plåtrickard]

Insert the plug into the hole, screw in a screw a few turns, and tap it to the desired depth with a hammer.

 

[toolman77]

Consider how thick the wall is and then be generous when choosing the length of the anchor. The fixing point should be as deep as possible without going through. Otherwise, you risk pulling out a large chunk from the wall.

As stated above, it's likely plastered brick; nylon anchors should work well in that case. Ordinary concrete anchors are too smooth to hold. They require very hard material (concrete) for a regular smooth anchor to work well. Keep in mind that it won't hold at all in the plaster, and you need to go quite deep into the wall. One option could be a deep hole where you push two anchors in one after the other. I recall hanging kitchen cabinets with 6x100 or 6x120 in an apartment with poor walls.

Those IKEA shelves create a very large moment on the bracket compared to a bracket that extends further down the wall. An alternative could be to simply change the shelves or supplement with brackets.

There are a couple of more extreme methods that almost always work.

Anchoring compound and screw, or anchoring compound and threaded rod. If it's really porous, you can supplement with a hollow plug, making the anchoring compound act like a mass of needles shooting into the wall. The screw or threaded rod cannot be disassembled and must be sawed off.

Rubber expansion, spacers, and threaded rod also work. They can be disassembled and patched even though the rubber expander remains in the wall.

If you have other walls where fine black powder that stains comes out, those are slag walls. Then long, coarse wood screws without pre-drilling or anchors are best. As long as possible without breakthrough. Slag walls are often thin.

 

[Mikael_L]

Brick usually works well without a hammer, I like Bosch Multiconstruction drills. I'm using these now as I'm fixing up the basement, although we have concrete hollow blocks and Leca there.

Do you have the right length of the screw in relation to the plug?

Yep, Bosch multiconstruction are pretty perfect here.
They can be googled as "bosch cyl-9" too.
Irwin also has them, they are quite the same kind, goodness, and quality, so you can choose based on price or which brand you prefer.
They're called something like "multi material drill bit," "cordless multi," "universalborr."

 

[13th Marine]

Set up just that kind of shelf in my previous residence, had render on a cast concrete wall.
I used Fischer's plugs, have been very satisfied with them but am starting to have trouble finding them in the well-priced 50/100 packs