Hello.
I am in the process of mounting my projector on the ceiling. Since it weighs around 70 kg and absolutely should not fall on anyone's head, I would prefer to use expansion bolts.
Now, I live in a rental apartment and would prefer not to deal with fixing the ceiling when I move out.
I was recommended to use Fischer's SX-10 plugs. They should withstand close to 300 kg with a safety factor of 3.
Is this a sensible idea? Concrete ceiling, 4 plugs in total, the load will be straight down.
Regards, bofr
I am in the process of mounting my projector on the ceiling. Since it weighs around 70 kg and absolutely should not fall on anyone's head, I would prefer to use expansion bolts.
Now, I live in a rental apartment and would prefer not to deal with fixing the ceiling when I move out.
I was recommended to use Fischer's SX-10 plugs. They should withstand close to 300 kg with a safety factor of 3.
Is this a sensible idea? Concrete ceiling, 4 plugs in total, the load will be straight down.
Regards, bofr
Use regular plugs, it will create 4 small holes (about 10 mm).
Drill through masking tape to minimize splitting.
I covered both the holes that were originally in the apartment (extra wall) + my projector holes with white electrical tape and in normal light, they were barely visible.
If you’re super serious, you can mask around the hole and fill plus paint. Any slight difference in shade is barely noticeable.
Drill through masking tape to minimize splitting.
I covered both the holes that were originally in the apartment (extra wall) + my projector holes with white electrical tape and in normal light, they were barely visible.
If you’re super serious, you can mask around the hole and fill plus paint. Any slight difference in shade is barely noticeable.
Otherwise, Fischer plugs are very good, I use them in our house, have never failed so far. SX-10 is probably 10 mm so why not use them? It won't be a bigger hole than in v-g's suggestion.
4 holes in a concrete ceiling are not difficult to fix when you move, just screw in the screws into the plugs, apply filler, and done. If you want, you can paint the filler a little with the same color as the ceiling. But probably white electrical tape as v-g writes will suffice; no one looks up at the ceiling anyway
4 holes in a concrete ceiling are not difficult to fix when you move, just screw in the screws into the plugs, apply filler, and done. If you want, you can paint the filler a little with the same color as the ceiling. But probably white electrical tape as v-g writes will suffice; no one looks up at the ceiling anyway
Yes, the plug is almost whichever. Screw in a plug, you should be able to easily HANG from it without it coming loose.
Certain concrete is porous and then it's difficult to get something to stay, but test it to be completely super sure. Then you can also feel if the plug "pulls," meaning you can tighten the screw.
I have no experience with the particular plug mentioned, so I won't comment on it, but it's probably good (just like most plugs when used correctly).
Certain concrete is porous and then it's difficult to get something to stay, but test it to be completely super sure. Then you can also feel if the plug "pulls," meaning you can tighten the screw.
I have no experience with the particular plug mentioned, so I won't comment on it, but it's probably good (just like most plugs when used correctly).
Ordinary plastic plug? Really?
They are completely smooth, consider that all the load is purely tensile.
The item really needs to hold like a rock. If I hang onto the projector after it's mounted, I don't want it to come loose. It mustn't slowly creep out either, which I've heard plastic plugs can do when the load is high, prolonged, and subjected to shocks.
Let's reframe the problem a bit.
Need to mount something on a concrete ceiling. Planning to use 4 drill holes. The weight will hang straight down, but it's not certain that the load will be evenly distributed over the fastenings.
Must withstand at least 70 kg constantly year after year. Must not shift due to temporary high loads (e.g., someone jumps up and grabs the object so that all this person's weight is transferred, repeating this once a second).
I'd much rather over-dimension than have it go terribly wrong; the object is large, heavy, with sharp edges, and not at all soft.
Priority list in descending order:
Durability
Removable fastening (or easily covered with plaster)
Number of holes
Best regards, bofr
They are completely smooth, consider that all the load is purely tensile.
The item really needs to hold like a rock. If I hang onto the projector after it's mounted, I don't want it to come loose. It mustn't slowly creep out either, which I've heard plastic plugs can do when the load is high, prolonged, and subjected to shocks.
Let's reframe the problem a bit.
Need to mount something on a concrete ceiling. Planning to use 4 drill holes. The weight will hang straight down, but it's not certain that the load will be evenly distributed over the fastenings.
Must withstand at least 70 kg constantly year after year. Must not shift due to temporary high loads (e.g., someone jumps up and grabs the object so that all this person's weight is transferred, repeating this once a second).
I'd much rather over-dimension than have it go terribly wrong; the object is large, heavy, with sharp edges, and not at all soft.
Priority list in descending order:
Durability
Removable fastening (or easily covered with plaster)
Number of holes
Best regards, bofr
I would skip regular plastic plugs. They work, but nylon plugs feel better. It matters less whether it's Fischer, Essve, or something else. Use at least 5-6mm screws, preferably more.
In fact, one properly tightened screw/plug should suffice.
If you want extra security, there are standard expanders for concrete too. They hold up to half a ton per attachment, but you'll need to drill 14mm. For instance, I'm thinking of Essve's Superplus expander. It's used for attaching construction elevators to concrete walls... Should be sufficient for you.
Essve (and surely others too) also offers regular concrete screws. Drill a hole and screw it in. They hold several hundred kilos per attachment.
In fact, one properly tightened screw/plug should suffice.
If you want extra security, there are standard expanders for concrete too. They hold up to half a ton per attachment, but you'll need to drill 14mm. For instance, I'm thinking of Essve's Superplus expander. It's used for attaching construction elevators to concrete walls... Should be sufficient for you.
Essve (and surely others too) also offers regular concrete screws. Drill a hole and screw it in. They hold several hundred kilos per attachment.
Thank you for all the answers.
I'm on the fence about whether to add an extra sprinkler and 6 Fischer plugs or 4 M8 expansion bolts.
I would prefer option 2... I reckon I could hang a car on them.
We'll see what I do.
If I can get hold of impact anchors somewhere, it seems like a nicer middle ground.
However, I haven't seen any in the stores I've rummaged through, Hilti has them but they tend to be reasonably expensive.
/bofr
I'm on the fence about whether to add an extra sprinkler and 6 Fischer plugs or 4 M8 expansion bolts.
I would prefer option 2... I reckon I could hang a car on them.
We'll see what I do.
If I can get hold of impact anchors somewhere, it seems like a nicer middle ground.
However, I haven't seen any in the stores I've rummaged through, Hilti has them but they tend to be reasonably expensive.
/bofr
If you screw in a screw+anchor and hang on it, then 4 screws should hold more than that, right?
A regular blue plug (not sure if it's plastic or nylon) used with standard plumbing sheet metal screws allows me (about 80 kilos) to hang on a single screw. So 4 should then support at least 320 kilos.
An anchor is usually smooth but has "barbs" that press outward when a sufficiently large screw is inserted, so you can see it as a 5 cm thick plastic piece that's just been screwed in.
All this assuming the concrete is okay; if not, you have to go for special solutions.
The advantage of an anchor where the screw is separate is that you don't have to cut the bolt inside the hole when you need to remove it. The anchor usually becomes deformed enough that it usually can be pulled out with needle-nose pliers, but that's not always possible.
Of course, no anchor is probably enough to swing on the projector mount
A regular blue plug (not sure if it's plastic or nylon) used with standard plumbing sheet metal screws allows me (about 80 kilos) to hang on a single screw. So 4 should then support at least 320 kilos.
An anchor is usually smooth but has "barbs" that press outward when a sufficiently large screw is inserted, so you can see it as a 5 cm thick plastic piece that's just been screwed in.
All this assuming the concrete is okay; if not, you have to go for special solutions.
The advantage of an anchor where the screw is separate is that you don't have to cut the bolt inside the hole when you need to remove it. The anchor usually becomes deformed enough that it usually can be pulled out with needle-nose pliers, but that's not always possible.
Of course, no anchor is probably enough to swing on the projector mount
A tip if you want to use expansion bolts and be able to cover your tracks one day is to drill the hole as deep as the entire bolt is long (plus a few mm).
When you then want to remove them, just knock the entire bolt in, fill over it, and voila, it's gone.
When you then want to remove them, just knock the entire bolt in, fill over it, and voila, it's gone.
There we go.
I have now mounted the bracket in the ceiling.
Used Fischer's sx 12x70 and four 10x90 French.
Required a sturdy damn wrench to tighten them, so this will definitely hold up nicely.
I'll hang up the projector itself once I've recruited some lifting help
Thanks for all the help.
Best regards, bofr
I have now mounted the bracket in the ceiling.
Used Fischer's sx 12x70 and four 10x90 French.
Required a sturdy damn wrench to tighten them, so this will definitely hold up nicely.
I'll hang up the projector itself once I've recruited some lifting help
Thanks for all the help.
Best regards, bofr
Strength data is available here: http://www.fischersverige.se/Portal...ing/_dokument/Kapitel_allmaen_infaestning.pdfbofr321 said:
NOTE: The value given is for load perpendicular to the direction of the screw, that is, how it is when you hang something on a wall. For axial load, the load-bearing capacity is probably significantly less.
Where do you actually see this? Looking at all the Hilti data sheets, both pull-out and shear loads are specified. Since Fischer only provides one value, shouldn't this, with all reasonableness, be the smallest of the two? Nowhere, neither on the packaging nor in the data sheets, is it said that the load must be perpendicular.anaitis said:
/bofr
I just mentioned Hilti as an example, they specify both tension and shear loads. Fischer doesn't seem to do this.anaitis said:
Anyway. http://www.hilti.se/data/techlib/docs/calculations_t/anchor_fasteners/60 plugg.pdf In this datasheet, there's Hilti's HUD-1, which appears to be somewhat similar to the regular S plug. (Nylon and roughly the same shape).
Looking at the table there, both tension and shear loads are specified. A 10mm HUD-1 plug with an 8mm wood screw would then in concrete handle roughly 200 kg in pull-out and almost 300 kg in shear load.
Fischer writes for its S plug 10mm and 8mm wood screw only one value, just over 100 kg.
Both calculations surely have a lot of adjustments, Fischer's value is with a safety factor of 7, Hilti says theirs is "safety class 1".
What this means is hard to say, but the plugs seem to be largely equivalent.
So for Fischer's plug to handle much less than 100 kg in pull-out when Hilti's plug according to the paper handles 200 kg in pull-out is very hard to believe.
Fischer's SX plug is apparently some kind of further development of the old S plug. According to their tables, they differ only by 10-20 kg.
All figures above are concrete values, Fischer's C20/25, Hilti K25. (same)
/bofr
So the plugs you are writing about have a 50% greater permissible lateral load compared to axial load.
To me, this seems like a significant difference.
To me, this seems like a significant difference.