Joist strength for hanging pull up bar on ceiling

[jeremy]

Hi all,

I want to hang pull-up bar on my ceiling in the garage and was wondering how to ensure it is strong enough and won't cause ceiling issues. I want to do 'Kipping' pull-ups which involve a lot of swinging so it will be quite a dynamic load.

The house is a brick veneer with tiled roof. (Project home 3 years old). The garage is 6m x 6m. It is a trussed roof. (I think a 'W' truss).

I was thinking of putting a block of wood 8x2 spanning a number of ceiling joists (maybe 5 or so) and then hanging the bar from this. Similar to http://www.crossfit.com/discus/messages/26/45908.jpg (however his joists appear much stronger than mine and mine aren't exposed).

Would this be strong enough? Or is there a better way of doing this?

Thanks,
Jeremy

[addo]

It should work; suggest 10 gauge galvanised chipboard screws rather than Paslode nails as our American friend has done. Predrill, then skew the screws in at a little angle, so they don't both lie in the same plane of the truss' bottom chord.

140×45 section size ought be adequate unless you're a heavyweight. If you start to hear cracking noises, back off and we'll find another way! As it's in a garage, make it in such a manner that it may NEVER be used for hoisting engines. You'd be amazed what some people will try...

Cheers, Adam.

[MrFixIt]

Hi

The house is a brick veneer with tiled roof. (Project home 3 years old). The garage is 6m x 6m. It is a trussed roof. (I think a 'W' truss).

You would be surprised at how little it would take to cause some disturbance to the structure of a roof.

Trusses can support a very substantial load VERTICALLY, how ever they do not support sideways loads too well. In your case the "sideways" load is your swinging.

If you want to pursue this installation then I would strongly recommend that you instal the pull up bar in such a way that the swinging motion is at right angles to the trusses. This way you can transfer the dynamic load across several trusses. The trusses are less likely to move sideways than they would be along their length. The manner in which SOME roofing contractors leaves much to be desired. If they can save nails they do. I know of some amazing examples

You do not say how accessible the trusses are, is the ceiling lined? if so it will be a little harder to install but not a major problem. I am NOT a proponent of using vertical screws of any gauge, to install heavy loads. I try to mount such items in a manner that the screws (or other fastener) is attached at a right angle to the load direction.

I would suggest a couple of 4x2's across five trusses. Use these to centrally support the pull up bar. If you intend to use pipe and pipe flanges to mount the bar, then I would also recommend that you drill holes through the 4x2's, pass the pipe THROUGH these holes and mount the pipe flanges ON TOP or the 4x2's.

In addition to this, I recommend you install "blocks" at the lower edge of the truss to help prevent the pipe from "swinging" on its mounting. See my rough sketch below

To futher ensure the stability of the trusses I also recommend you place "filler blocks" between the trusses at the truss ends and nail them to the top plate.

If it is possible, it would be better to mount the 4x2's in an "X" manner with a half lap joint at the centre of the "X". Such a mounting will hlep minimise any potential flexing of the trusses, or consider mounting supporting pieces across the corners to help provide strength against any flexing.

PLEASE consider that (especially these days of cheap and rapid house construction) that they DO NOT build houses like they used to and they only build roofs to support a vertical STATIC load.

I would NOT trust the mounting as shown in your example, to hold a dynamic swinging load. The frequent use would (IMHO) eventually "break down".

[Bloss]

MrFixit is the gold standard, but given that what you are suggesting is your body weight swinging on a bar the most important issue is the attachment mechanisms - not movement of the roof members which IMHO is highly unlikley.

Any trussed roof will easily withstand the sort of forces you would be able to apply by swinging on such a bar even if you simply bolted up through a hole drilled through the bottom chord of a single truss (but do not do that). The design just to meet wind loads will be much greater than what you can apply.

As was said jokingly you would in fact hear and feel movement of the major roof structure so would have some indication that you need to strengthen it, but badly placed or insufficiently strong fixings of the bar or attachments might fail catastrophically ie: without warning.

But as suggested spreading the load across a few trusses and via some added load bearing timbers (you could use light steel) is a sensible way to do this. Bolts and washers rather than screws are the go so just make sure that the fixings are solid, secure and of a decent rating (so >10mm bolts for example). MrFixit's drawings are a great start although there would be little need for the blocks above the wall plates.

[jeremy]

Hi,

Thanks for the detailed replies, they were excellent. Looking again at my Garage again I can actually bolt some horizontal bars from the pull-up bar to the double brick pillars which hold up one side of the garage which will reduce the sideways forces on the trusses. That combined with the suggested construction in your replies should make it bullet proof (at least for my weight).

Thanks again,
Jeremy

[MrFixIt]

Hi

Hi,

Thanks for the detailed replies, they were excellent. Looking again at my Garage again I can actually bolt some horizontal bars from the pull-up bar to the double brick pillars which hold up one side of the garage which will reduce the sideways forces on the trusses. That combined with the suggested construction in your replies should make it bullet proof (at least for my weight).

Thanks again,
Jeremy

I would be wary of bolting bars to the double brick pillars. They too are designed for VERTICAL loads and though the sideways weight/force may be small, many small "jolts" in the horizontal direction may (IMHO) cause cracks in the mortar.

From personal *experience* I have very little faith in many bricklayers these days. Like (too) many trades in the construction industry, they build to either a time frame or a cost factor that ALWAYS minimises the *QUALITY* of construction.

As brick piers in a garage/carport are *supposed" to be tied into the concrete footings AND tied into the roof, and any induced cracks would/could be a big job to repair correctly.

If you want/need this additional support then please mount the bars to some timber, maybe 750/900mm long that you attach to the piers, at least this would spread any sideways load over a longer area.