Putting up a punchbag - help with bolts

[mouk]

Hi

I am putting up a punchbag in my garden. The bracket will be affixed with 3 bolts. I am aware that punchbag will put some stress on the wall so want a secure fit.

The punchbag will be attached to the outside of my shed which is made of concrete blocks (breeze blocks) and the wall is approx 80mm thick.

As far as I can see I have 2 option

Use expanding bolts (aka sleeve anchor/thru bolts) - are these all the same thing?

The issue I have with these is that in the past they have caused brick walls to crack. As I will probably be going in 60mm of 80mm I am worried they will cause damage when they expand.


The other option is I drill all the way through and use a nut to tighten on the otherside. This to me feels like it would be a more solid connection. My query is - what fixing do I need - is it a hex bolt? As such: http://s7g1.scene7.com/is/image/BandQ/5020789852589_001c_v001_ap?$173x173_generic$=

Any other suggestions?

Also I am planning on using my normal drill as opposed to SDS to stop the SDS smashing up the wall. Am I right to do so? Hopefully my normally drill will do the job if I get a good drill piece.

 

[Burnerman]

I'd go for the bolt through method, with large washers or plates on the inside of the wall.
You can always use threaded studding plus nuts and washers if you want - readily available. 10mm diameter should be fine.
To reduce break out when drilling through, use a small diameter masonry bit first, followed by the correct clearance size......it doesn't matter if its SDS or not, but a masonry bit is essential with a percussion drill.
Once the small hole is right through, drill from both sides to just over half way with the larger bit.
John

 

[Alastairreid]

Ditto John!
Sleeve anchors wont last long because of the vibrations on the bracket.
You need to distribute the load by plating the other side.

 

[kjacko]

I know it's probably obvious, but when drilling, once you get 80% of the way through, just take the hammer action off for the last 20% to avoid blowing the brick face off.

 

[foxhole]

You will need a timber[ply] plate behing the bag fixing to spread the load.

 

[mouk]

Thanks for the responses

So just buy 3 hex nuts with washers and bolts and then get a sheet of ply that will go on the wall inside the shed and the washers/nuts will then go onto that?

With regards to the hole, I think I can use 10mm holes as that is the hole size on the metal wall bracket - so I should use 10mm bolts which will literally fill up the hole in the wall to a very snug fit.

 

[Pigeon85]

You will need a timber[ply] plate behing the bag fixing to spread the load.

I suggest the same but on both sides of the wall

 

[mouk]

My wall moutn is liek this

http://i.ebayimg.com/t/Auth-RDX-Hea...==/$T2eC16hHJH8E9qSEYOQqBP-0TtGoyQ~~60_35.JPG

would you suggest I have like a square block of ply which is as big as the wall mount

or you would suggest i have 2 smaller pieces - one at the top and one at the bottom - not connected

its not big deal other than it might be cheaper buying half as much ply.

only other things - if i have one on the outside would it not perish with bad weather?

also would the pressure of the nut digging into the ply not damage it? from memory ply is pretty solid though.

 

[Pigeon85]

Changed my mind on the ply after seeing the picture.

I think a bit of 4x2 would be sufficient, still use washers either side. And give it a paint or wood treatment of some kind.

 

[mouk]

one more thing - my shed is made of breeze blocks - the roof is made of wooden beams with some sort of rough material on top.

One of my worries was that the bracket will fix to the block that is on top and that it might start detaching from the block underneath - the roof is not rock solid on top - although i am probably over thinking this

my other thought was to get a massive fence post and put it on my (flat) roof and have it overhang - then I could just attach it from above. downside to this is obvious an unweidly fence post on my shed roof.

 

[Pigeon85]

I think that if you went with the 4x2 idea then you would have to run them vertical so that you are in affect bracing the blocks together which will add strength, but would also try to avoid attaching the frame to the top blocks.

How heavy is the total weight of frame and bag?

What you want is a structural engineer to come along.

 

[Burnerman]

I think I'd consider reinforcing the inside of the wall with a longer horizontal timber -25mm plywood maybe - and spread the load over the top layer of blocks and the layer beneath.
More bolts could help with the fixing of the ply beam at the ends.
John

 

[mouk]

Here are some pics of the shed

pic 1 - the outside where it will hang

pic 2 - inside showing the roof going above

pic 3 - inside where bolts would come in. I am guessing the bolts would come in just under the top later of cement

http://postimg.org/gallery/an6exiki/

May not be the best construction in the world but its fine for storing goods in and is solid in that respect. I just think i have made myself too worried!

the fence post on the roof sounds more appealing. shed is 2m so if i got a 2.4m fence post i would overhang it and mount from that

the bag is between 25 and 30kg.

original i bought a huge bag which was 40kg+ but i decided straight away i wasn't going to use it - the guy i bought it off said it was causing his shed to crack which is why i am now having second thoughts.