Jump to content

Fixing a bar in the apex of a roof


Stuart91

Recommended Posts

I've got another "awkward" installation coming up. The client is looking to have a lighting bar fixed into place, but up in the apex of a pitched roof. Headroom is relatively limited, so we don't have the luxury of being able to bring anything further down, it has to be mounted as tightly to the roof as we can manage.

 

It's just standard 48mm pipe, and the SWL will be minimal. Plus there are plenty of roof joists available, so we can fix in multiple places if required. Total run is 7m and the joists are at 18" centres. I saw them before the gyproc went on, and they are pretty sturdy 6x4" timber that should take a fixing without any worries.

 

I don't know the exact angle of the roof, at a very rough guess I would say 90 degrees or similar.

 

We can think of a few ways of tackling this, but most will be either ugly or cumbersome. I figure there must be a more elegant way of doing this, possibly some hardware more suitable for the task that I haven't found yet. Can anyone suggest anything?

Link to comment
Share on other sites

So not an IWB with a box on the end?

 

I'd just use Doughty ceiling saddles on alternating sides of the roof bolted to Doughty universal clamp round the bar

 

Or ask Doughty if they could modify their pipe to wall brackets to have 45 degree angles on the end.

Link to comment
Share on other sites

This sounds like a job for channel brackets, commonly used for mounting communication aerial poles close to a wall. They come in 100mm and 150 mm sizes as standard. They are normally fixed in position with a rawlbolt but you could replace this with a suitable coach screw. The pole is held by a U bolt. They have the advantage of being properly galvanised. Obtainable via the larger satelite aerial suppliers or could easily be knocked up by your local steel fabricator.

Brian

 

http://www.radiostructures.com/bracketry/galvanised-wall-mounting-channel-brackets-c/w-rawl-bolts-u/bolts-5-6-/prod_53.html

Link to comment
Share on other sites

What are you planning to put on a bar so close to the apex- will it generate heat? I can envisage all sorts of products having a significantly reduced lifespan in dead warm air
Link to comment
Share on other sites

Thanks for all the replies.

 

It's just a plain bar, no IWB trickery, no boxes or sockets being fitted to it.

 

The only items likely to be mounted to it are some LED pars and fresnels, no incandescents so hopefully heat won't be a big issue.

 

Unfortunately there's no other logical place to mount anything. If we go down the roof even slightly, the lanterns will be within accidental whacking distance. It's a small cabaret / studio venue.

 

Channel brackets look interesting - I don't think I've seen anything quite like that before.

 

Doughty saddles have been my go-to for similar things in the past. I suppose I could use a short section of threaded rod between the saddle and the universal clamp to take up the distance.

 

The other thing that's caught my eye is these clamps from Global. The 45 degree version might be an option, especially since it can be rotated around the bar to get the exact angle.

Link to comment
Share on other sites

This is too obvious for a man of your calibre but I have seen it done so many times; make sure that once you have your bar neatly and securely right up into the eaves you can still get a lantern/hook clamp onto it without a sledgehammer.

I did one gig once where the former PM had designed a ground support lighting rig on the drawings of the footprint of the tent. To get it in below the angled roof the stage was 6 metres further forward and the lead singer had his very own tent pole alongside his mic stand.

Link to comment
Share on other sites

This is too obvious for a man of your calibre but I have seen it done so many times; make sure that once you have your bar neatly and securely right up into the eaves you can still get a lantern/hook clamp onto it without a sledgehammer.

 

Good point Kerry - it has crossed our minds and we will double check before any fixings go in. The other potential snag (given the steepness of the ceiling) is that yokes could potentially foul it too - so it might be helpful if we are a little lower anyway.

 

I did one gig once where the former PM had designed a ground support lighting rig on the drawings of the footprint of the tent. To get it in below the angled roof the stage was 6 metres further forward and the lead singer had his very own tent pole alongside his mic stand.

 

I had something similar where the client asked for 3ft legs on their staging, probably plucking the figure out of midair. We turned up with the staging to find that it was going under a tent with ~7ft eves. The audience, viewing from outside, could only see the dancers from the waist down. It was a strangely perverse spectacle.

Link to comment
Share on other sites

I had something similar where the client asked for 3ft legs on their staging, probably plucking the figure out of midair. We turned up with the staging to find that it was going under a tent with ~7ft eves. The audience, viewing from outside, could only see the dancers from the waist down. It was a strangely perverse spectacle.

 

 

 

 

We had this too, the stage was set behind and level with a 4ft wall but the marquee Co. had put the 30x30ft roof 90 degrees out of kilter so the 'eaves' was well under 3ft above the stage.

 

As the marquee Co. could not get back to turn it the event organisers had the brilliant idea to cut a big chunk of the roof panels out. It meant there was a 'handrail' across the front of the stage and 2 sloping beams from there to the apex which received many bumps during the days dozen or so bands performances. Fortunately the weather was brilliant, unlike the following year.

 

This is too obvious for a man of your calibre but I have seen it done so many times; make sure that once you have your bar neatly and securely right up into the eaves you can still get a lantern/hook clamp onto it without a sledgehammer.

 

Also check for clearance for the light fittings (especially very square yokes) against the sloping ceiling, I've known many situations where the bar is too close to a wall, accepting patt 123's on a steep downward aim maybe but not much else

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.