Expander bolt disaster - how do I attach the wall chair now (aerated concrete)
I attempted to mount an Edblads wall chair in the basement. They recommend French screws with plastic plugs or 10 x 80 mm expansion bolts for mounting. I tried with expansion bolts, but the wall betrayed me. The lightweight concrete was so weak that the bolts were barely guided by the drill hole - they leaned or almost disappeared completely into the wall. Those that did get a grip pulled themselves loose when I tried to tighten the nut. Disaster!
So... what do I do now?
Can I refill the holes with the hope of trying again in the same spot?
If I mount the chair on another part of the wall - which fastener might give a better result? Went to Byggmax and bought all the options in approximately the right dimensions (~10mm), lightweight concrete plugs, and longer facade plugs.
Is there anything here that you think has a better chance than the expansion bolts?
Drill holes so that the plastic plugs for lightweight concrete go in completely. These plugs are quite coarse. Then mix some "husfix" or another quick-setting cement and press it into the holes. Insert the plugs and cast them in place. Then drive in the wood screws.
Expansion bolts and lightweight concrete do not go together, at least not when I tested.
I've tried several of those in your picture, including the gray/red Fischer and the metal ones with "wings."
I did a test when I installed an Ikea kitchen.
The ones that were by far the best were the Fischer GB8 plugs. Pre-drill in the same dimension as they recommend on the package.
Then it's a bit of work to hammer them in. But they hold really well, in my opinion.
In general, when pre-drilling for plugs in lightweight concrete, I think you should pre-drill with a slightly smaller dimension drill bit.
I've tried several of those in your picture, including the gray/red Fischer and the metal ones with "wings."
I did a test when I installed an Ikea kitchen.
The ones that were by far the best were the Fischer GB8 plugs. Pre-drill in the same dimension as they recommend on the package.
Then it's a bit of work to hammer them in. But they hold really well, in my opinion.
In general, when pre-drilling for plugs in lightweight concrete, I think you should pre-drill with a slightly smaller dimension drill bit.
Now that the holes are drilled and everything is screwed up, I would probably buy anchor compound and secure the expander or threaded rod.
For aerated concrete, I usually use long aerated concrete screws, but it's too late now.
For aerated concrete, I usually use long aerated concrete screws, but it's too late now.
Now that the holes have become too large, use anchoring adhesive so you don't have to drill new holes.
P.S. runner-up on that...
P.S. runner-up on that...
I would have used the holes you already made and glued the expansion screws with anchor mass.ulfben said:
Simple and holds very well.
https://www.biltema.se/bygg/kemikalier/ovriga-kemikalier/ankarmassa-165-ml-2000052945
Anchor compound will solve this. Just buy and follow the instructions. I've had the same problem once.
I hate lättbetong. 😂
Buy some tape as well so you can tape up the chair while the compound cures; it will be hell if the rods aren't where they're supposed to be, so use the chair as a jig or make a jig out of a piece of plaster.
Otherwise, I would recommend gummiexpander.
Otherwise, I would recommend gummiexpander.
I cleaned and blew out the holes, then filled them with anchor resin, then inserted a plug (plastic) and then filled the entire hole/plug with anchor resin again (topped it up) and then screwed it in place. So it held immediately, then the anchor resin cures and you can hang the hammock on it without any problem.A atomlab said:
This method handled great loads!
I doubt that you can attach that chair to a lightweight concrete wall. There will be a lot of torque and pulling force on the upper attachment points if a person weighing 80kg sits in it.
You don't think I can "reinforce" the wall by overfilling with anchor mass? I watched essve's instructional video on how they do it in brick and lightweight concrete - the mass spreads quite well in all cavities. My thought is that the bolt would then have to pull out the entire block's inner material to come out. But you don't think that's enough?
richardtenggren
Ingen-gör
· Norrlandet
· 6 614 posts
richardtenggren
Ingen-gör
- Norrlandet
- 6,614 posts
I would also go with anchor adhesive unless the back of the wall is positioned in such a way that a through bolt with robust washers would not be an issue 🤓
Well... In lightweight concrete, you're supposed to, according to some systems, drill a conical hole. Which is significantly larger at depth than at the surface. So the idea is basically correct. But stick to the installation instructions, as that's likely the method that provides the best durability.
Personally, I don't think it's a problem.
Tough situation.
Personally, I would go for the suggestion to place a plate on the back if possible, as there are tremendous forces with that type of chair. If the back is not accessible, perhaps you can glue and screw a piece of plywood on the entire front, making it easier to attach the chair to it.
Personally, I would go for the suggestion to place a plate on the back if possible, as there are tremendous forces with that type of chair. If the back is not accessible, perhaps you can glue and screw a piece of plywood on the entire front, making it easier to attach the chair to it.