Floods on insulated steel buildings

[loz]

got a few 100w floods to mount on a newbuild. The walls are clad with insulated cladding, outer tin strip, insulated ion, thin tin strip. I can't get a fixing into the top purling, due to guttering. The client wants the floods mounted between en the top 2 purlins. I was thinking 2 bits of units rut outside horizontally (to span the corrigations) bolted through into 2 more bits of strut about a foot long mounted vertically to spread the weight of the fitting? I really don't want to crease the building, or even worse have a light come down in windy conditions

 

[snowhead]

Whatever you do you need to get agreement for exactly what you are going to do.

If it was my new building I wouldn't want Unistrut showing everywhere on the outside.

How heavy are these fittings?

Are the Cladders still on site or is there any cladding trim bits left?

 

[loz]

Whatever you do you need to get agreement for exactly what you are going to do.

If it was my new building I wouldn't want Unistrut showing everywhere on the outside.

How heavy are these fittings?

Are the Cladders still on site or is there any cladding trim bits left?

I was thinking the vertical strut on the inside so the fitting would be secured through the building, the only strut outside would be behind the light in order to bridge the corrigations.

The cladders have left some trim on site, are you thinking bolt a strip through 2 corrigations so bolts go through the building and nut and washer on the inside, then bolt light to this strip. This had crossed my mind, at least any flexing in wind would at worst bend this strip, and not the cladding?

The lights aren't massively heavy, I'm more concerned about the effects of wind.

I'm not keen on trek screwing to the cladding as I don't think such a thin material can support a sturdy screw fixing, hence bolting through to the inside.

 

[cdavies33]

You can get stitch screws for this job. They get wider and wider as you go, hang yourself off them ha. use strut horizontal to spread the weight and have 4-5 fixings made and mount flood to strut.

TIMco Stitching Screw for Light Section Steel - 6.3 x 25mm | Ironmongery Direct - http://www.ironmongerydirect.co.uk/products/screws_and_fixings/roofing_and_self_tapping_screws/12513/timco_stitching_screw_for_light_section_steel/889096?vat=1&shopping=true&gclid=CL6dmKP0zs8CFSIo0wodsGYIlw&gclsrc=aw.ds#specification

 

[telectrix]

i'd use a short piece of unistrut behind the light ( long enough to bridge at least one corrugation ) and bolt through to a longer piece on the inside, then fix flood with zebedees.

 

[sunray]

If these are 100W LEDs will the bracket holes reach adjacent corrugations?
If so 2 internal verticals, zeb and bolt direct. Dont forget to use a sealant.
Used this method for T&K brackets, but you won't need to attatch to the cladding horizontals.

 

[Leesparkykent]

Drill a 16mm hole for each fixing and use toggle bolts with a washer. Done it loads of times to fix Floods to metal clad commercial/industrial units. Recently done 9 units, you can just about make out the fitting above the roller shutter doors which is a 70W son and fixed using toggle bolts.

 

[loz]

Thank you for your input guys, it's been really helpful. I must say I massively underestimated the rigidity of the cladding, I was concerned that as soon as you tightened a fixing through it would just crush the two layers, this certainly wasn't the case.

In the end I cut a length of strut to fit between 2 corrigations, and hooted through into another length of strut horizontally inside using some m8 stud rod and double jutted to prevent the bolts coming loose over time. The light brackets were about 10mm wider than the gap between the corrigations. This proved to be really sturdy, and should last the test of time.

I've seen so many lights just stuck up with woodscrews or trek screws into the outer layer of tin, and can only see this leading to problems after a few years of wind rattling the bracket around.

 

[sunray]

Thank you for your input guys, it's been really helpful. I must say I massively underestimated the rigidity of the cladding, I was concerned that as soon as you tightened a fixing through it would just crush the two layers, this certainly wasn't the case.

In the end I cut a length of strut to fit between 2 corrigations, and hooted through into another length of strut horizontally inside using some m8 stud rod and double jutted to prevent the bolts coming loose over time. The light brackets were about 10mm wider than the gap between the corrigations. This proved to be really sturdy, and should last the test of time.

I've seen so many lights just stuck up with woodscrews or trek screws into the outer layer of tin, and can only see this leading to problems after a few years of wind rattling the bracket around.

Yes, I've seen them fitted with a couple of self tappers or tek's and in no timethey start sagging

 

[sunray]

How do I keep double posting?