Breeze blocks, heavy duty fixings and a rabbit hole
Discussion
Going down my usual rabbit hole and would appreciate some sanity...
I want to mount a pullup bar to an internal wall to support at least 100kg; the bar itself is rated for 150kg.
- Internal wall is ~10mm plasterboard, ~40mm breeze block (seems to be hollow block).
- Steel frame where the fixing bolts through is 25.4mm
There were 1 and a half set of fixings that arrived with the bar.
A set of coach screws without plugs and a set of, what looks to be sleeve fixings.
I was about to fix the sleeve fixings but the expansion part of the sleeve will end up in the void, so thats no good. I was going to cut the non expansion part of the sleeve down so it engages in the wall but theres not enough thread on the bolt.
I'm not sure what category breeze blocks are so with plugs 2kg to 120kg, although the latter cant be true as that ,much be solid concrete. Are breeze blocks 'aerated concrete' ?
https://fiproductmedia.azureedge.net/media/Load%20...
Then I thought balls to this and was going to pop out and get some fixings but Ive read some expansion anchors can crack blocks and thus, resin fixings with threaded rod should be used. The latter are apparently rated for a couple hundred kg.
Can you use shield anchors with breeze block?
Options to me seem to be buy some sleeve fixings e.g.
https://www.screwfix.com/p/easyfix-sleeve-anchors-...
Although these dont account for 25mm of box section.
Or resin anchors something like this:
https://www.screwfix.com/p/rawlplug-r-kem-ii-styre...
https://www.screwfix.com/p/easyfix-bzp-steel-threa...
Ive mounted loads of things to walls in the past but am slightly cautious about this as I rather but wear this thing as a hat.
I want to mount a pullup bar to an internal wall to support at least 100kg; the bar itself is rated for 150kg.
- Internal wall is ~10mm plasterboard, ~40mm breeze block (seems to be hollow block).
- Steel frame where the fixing bolts through is 25.4mm
There were 1 and a half set of fixings that arrived with the bar.
A set of coach screws without plugs and a set of, what looks to be sleeve fixings.
I was about to fix the sleeve fixings but the expansion part of the sleeve will end up in the void, so thats no good. I was going to cut the non expansion part of the sleeve down so it engages in the wall but theres not enough thread on the bolt.
I'm not sure what category breeze blocks are so with plugs 2kg to 120kg, although the latter cant be true as that ,much be solid concrete. Are breeze blocks 'aerated concrete' ?
https://fiproductmedia.azureedge.net/media/Load%20...
Then I thought balls to this and was going to pop out and get some fixings but Ive read some expansion anchors can crack blocks and thus, resin fixings with threaded rod should be used. The latter are apparently rated for a couple hundred kg.
Can you use shield anchors with breeze block?
Options to me seem to be buy some sleeve fixings e.g.
https://www.screwfix.com/p/easyfix-sleeve-anchors-...
Although these dont account for 25mm of box section.
Or resin anchors something like this:
https://www.screwfix.com/p/rawlplug-r-kem-ii-styre...
https://www.screwfix.com/p/easyfix-bzp-steel-threa...
Ive mounted loads of things to walls in the past but am slightly cautious about this as I rather but wear this thing as a hat.
I’d go for something like this: https://www.screwfix.com/p/dewalt-blue-tip-2-flang...
No expansion in the block and (unlike resin fixings) can be removed.
No expansion in the block and (unlike resin fixings) can be removed.
LooneyTunes said:
I’d go for something like this: https://www.screwfix.com/p/dewalt-blue-tip-2-flang...
No expansion in the block and (unlike resin fixings) can be removed.
They won't work in hollow blocks, if the OP does indeed have hollow blocks.No expansion in the block and (unlike resin fixings) can be removed.
OP needs to check the plasterboard as well, as its likely the plasterboard is 'dob and dab' so there will be the air gap between back of plasterboard and face of blocks to consider, which can crush when torqueing bolts up.
I think OP will need to be looking at some sort of resin injection method, if OP does indeed have hollow block construction inner leaf wall.
aeropilot said:
LooneyTunes said:
I’d go for something like this: https://www.screwfix.com/p/dewalt-blue-tip-2-flang...
No expansion in the block and (unlike resin fixings) can be removed.
They won't work in hollow blocks, if the OP does indeed have hollow blocks.No expansion in the block and (unlike resin fixings) can be removed.
OP needs to check the plasterboard as well, as its likely the plasterboard is 'dob and dab' so there will be the air gap between back of plasterboard and face of blocks to consider, which can crush when torqueing bolts up.
I think OP will need to be looking at some sort of resin injection method, if OP does indeed have hollow block construction inner leaf wall.
Ive drilled 3x 10mm holes to take a peak (correct locations places to mount the first steel).
I must have hit mortar in 2 of them; no cavity 70mm deep.
The middle hole definitely has a cavity as I used a solid wire with a bent end as a prove and its ~50mm including the plaster.
This is what leads me to believe its hollow block.
Doesnt seem to be any gap between the plaster and breeze block...?
aeropilot said:
LooneyTunes said:
I’d go for something like this: https://www.screwfix.com/p/dewalt-blue-tip-2-flang...
No expansion in the block and (unlike resin fixings) can be removed.
They won't work in hollow blocks, if the OP does indeed have hollow blocks.No expansion in the block and (unlike resin fixings) can be removed.
OP needs to check the plasterboard as well, as its likely the plasterboard is 'dob and dab' so there will be the air gap between back of plasterboard and face of blocks to consider, which can crush when torqueing bolts up.
I think OP will need to be looking at some sort of resin injection method, if OP does indeed have hollow block construction inner leaf wall.
Looking at the OP’s instructions it is two brackets spitting vertically on the wall, top fixings will be in tension and bottom in compression.
As block type is uncertain and loads significant I would go with resin anchors at the top, at the bottom I would make some 40-50mm holes in the plasterboard where the fixings are to go and fill them level with finish plaster so there is something solid under the bracket.
When selling the house an angle grinder will take the fixings below plaster level, or just leave the bar behind.
As block type is uncertain and loads significant I would go with resin anchors at the top, at the bottom I would make some 40-50mm holes in the plasterboard where the fixings are to go and fill them level with finish plaster so there is something solid under the bracket.
When selling the house an angle grinder will take the fixings below plaster level, or just leave the bar behind.
Jeremy-75qq8 said:
Think the op needs to be clearer as to what then happens to the steel bar …
See pictures here... Its for abs and upper body training for the sports I do.Bodyweight offset out from the wall by 60cm (I dont weight anywhere near 100kg
).https://www.networldsports.co.uk/metis-wall-mounte...
As mentioned by IJWS15, its more than just shear load as the top will be in tension.
There are 3 bolts in each steel bracket.
wolfracesonic said:
I’d go with resin and threaded bar, the walls of hollow blocks aren’t particularly thick, so I’d use resin fix sleeves as well, to stop the resin escaping, the pic gives the idea.
Good idea, added them to the basket.IJWS15 said:
Looking at the OP’s instructions it is two brackets spitting vertically on the wall, top fixings will be in tension and bottom in compression.
As block type is uncertain and loads significant I would go with resin anchors at the top, at the bottom I would make some 40-50mm holes in the plasterboard where the fixings are to go and fill them level with finish plaster so there is something solid under the bracket.
When selling the house an angle grinder will take the fixings below plaster level, or just leave the bar behind.
Thanks, will do and I thought as much WRT removal As block type is uncertain and loads significant I would go with resin anchors at the top, at the bottom I would make some 40-50mm holes in the plasterboard where the fixings are to go and fill them level with finish plaster so there is something solid under the bracket.
When selling the house an angle grinder will take the fixings below plaster level, or just leave the bar behind.
If you can live with the aesthetic, I'd seriously consider mounting vertical Unistrut to the walls, and then fastening the pull-up bars to the Unistrut.
That way you can have as many fixings as you like to the walls, and can carry the vertical loads into the floor.
The problem with this sort of pull-up design is that whilst the lower set of mounting holes will see primarily shear stress (parallel to the wall surface), the upper set of mounting holes will see a considerable amount of pull-out force. With a hollow block, you're reliant upon the small amount of concrete block to resist that force (so potentially either break-out of the block, or failure of the fixing).
Unreinforced hollow blocks are not suitable for serious expansion anchors. That leaves either resin or Tapcon-type screw-in types. Tapcons are easy to strip (with too much tightening), and aren't great for pull-out loads. Resin can be fine. And sometimes isn't.
So, as I say, you could fit vertical Unistrut (or similar - the cheap compatible channels will have plenty enough load-carrying capacity for your needs) to the walls, secured by Tapcons every foot or so, the Unistrut bearing on the floor, and perhaps use resin anchors for the top-most fixings (belt and braces). Then secure the pull-up bars to the Unistrut with bolts and channel nuts in the usual manner. That also has the benefit of allowing you to change the bar height in the future, in case that's useful.
But if you can't live with Unistrut, use long resin sleeves as mentioned previously, and be liberal with the resin before setting the studs.
That way you can have as many fixings as you like to the walls, and can carry the vertical loads into the floor.
The problem with this sort of pull-up design is that whilst the lower set of mounting holes will see primarily shear stress (parallel to the wall surface), the upper set of mounting holes will see a considerable amount of pull-out force. With a hollow block, you're reliant upon the small amount of concrete block to resist that force (so potentially either break-out of the block, or failure of the fixing).
Unreinforced hollow blocks are not suitable for serious expansion anchors. That leaves either resin or Tapcon-type screw-in types. Tapcons are easy to strip (with too much tightening), and aren't great for pull-out loads. Resin can be fine. And sometimes isn't.
So, as I say, you could fit vertical Unistrut (or similar - the cheap compatible channels will have plenty enough load-carrying capacity for your needs) to the walls, secured by Tapcons every foot or so, the Unistrut bearing on the floor, and perhaps use resin anchors for the top-most fixings (belt and braces). Then secure the pull-up bars to the Unistrut with bolts and channel nuts in the usual manner. That also has the benefit of allowing you to change the bar height in the future, in case that's useful.
But if you can't live with Unistrut, use long resin sleeves as mentioned previously, and be liberal with the resin before setting the studs.
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