CaptainPolaroid t1_ire0kf7 wrote on October 7, 2022 at 10:22 AM

Filling it with a harder material wil just result in ripping a large hole because the rest of the wall is still soft AF.

I'm going to be blunt. Anyone that says anything else than put in some proper bracing should be banned from ever installing a hand railing. People hang on these with their full weight pulling themselves up stairs. If you fall. What do you grab? The railing! That's a dynamic load that can exceed your body weight. Even though there is "no safety issue"with falling down a 5cm gap. You can still fall down the stairs when the handrail gives and you lose your grip.

Don't muck about with this stuff. Broken bones can be the least of your worries after a good tumble down the stairs..

Find the studs and screw your rail holders there. Reposition all of the rail holders to studs. You can then fix the hole normally with putty, filler or whatever.

Another solution would be to rip out a section of drywall and get some wood or plywood behind / in-between fastened to the studs. After replacing the drywall, you can then safely use bolts or plenty screws to secure the handrail in the same spot.

flying-benedictus OP t1_ire9q58 wrote on October 7, 2022 at 12:15 PM

English is my L2 language, I looked up stud and it seems it's usually referring to wood. There's no wood behind, only metal. There's already a hole in the metal, but how can I attach something to it? Making a hole at the other side to place a nut is an option, but really, is there no option that doesn't require ripping off my wall from the other side?

I've thought about rivets, since it allows to create a widening behind the hole without having to place a nut or similar. But afaik most rivets are made of aluminium and the hole is 8mm, so it may not be very strong.

I am trying with this https://webshopresources.silvan.dk/resources%2fimages%2f1807876_large.jpg?id=1570697940000&width=1230&height=1230 but I am having trouble closing it, because the plug turns with the screw, since the two little spikes skid over the metal stud.

CaptainPolaroid t1_iree0l2 wrote on October 7, 2022 at 12:56 PM

What is your native language?

If there is metal behind the wall, this means it's a 'metal stud' wall. As a whole, the wall has a lot of sturdiness because of all the connecting components. But I have no experience mounting something as important as a handrail to it.

Personally, I would opt to get backing in there: https://www.google.com/search?q=metal+stud+backing&tbm=isch&ved=2ahUKEwij5oyUlM76AhXjgv0HHQE8AqQQ2-cCegQIABAA&oq=metal+stud+backing&gs_lcp=CgNpbWcQAzIFCAAQgAQyBQgAEIAEOgQIIxAnUNIGWOIKYNgLaABwAHgAgAFEiAGcApIBATaYAQCgAQGqAQtnd3Mtd2l6LWltZ8ABAQ&sclient=img&ei=qyBAY-PkJ-OF9u8PgfiIoAo&bih=937&biw=1920&rlz=1C1VDKB_nlNL982NL982

But this requires ripping out a section of wall.

I think as an alternative you could mount a backboard to the front of the wall that follows the handrail (example). That way you can secure to the studs where possible and get more screws in there. This will spread the load. But since I have no experience with metal stud, I would prefer it if someone corroborates this.

Peopletowner t1_irehsup wrote on October 7, 2022 at 1:29 PM

Could be referring to metal lathe if a plaster wall. Doesn't sound like op should be doing this particular project themselves.

CaptainPolaroid t1_irejlct wrote on October 7, 2022 at 1:44 PM

Oh. Right. Good point. I assumed metal stud as he has plasterboard.

flying-benedictus OP t1_irho8w6 wrote on October 8, 2022 at 6:16 AM

Spanish.

The handrail is made of welded metal and connects only to the stairs, which are floating, so the fastening to the wall is preventing the rail from wobbling. Perhaps something could bend badly if a lot of sideways force were applied and the fastening to the wall is nonexistent, but at least among fit adults you would need a quite reckless behaviour for this, since once one notices it's loose, one can just stop using it when walking up the stairs (it just takes a bit more load on the legs when doing it so many times a day). But it's never gonna fall or anything like that, since the other points are very firmly attached to the metal frame that holds the floating stairs. So the setting in the image is not possible, but I have considered attaching a vertical wooden panel to the wall to grab from different points to the wall, and then the end of the rail to that.

But for the moment I managed to make it quite secure with that metal dowel I mentioned in the last post. If it gets loose again I may consider the plank, or making a hole at the other side.

As for whether the metal behind is just a stud for the plasterboard or something stronger, I don't know. It's a 250-year-old-house renovated 40 years ago, and has a combination of old wooden and newer metal structure inside. Could be a bit more structural than just the metal studs used to hold the plasterboard in place, especially since it's a corner of sorts, but it's very difficult to know.