what frame can i use for lightbox mounting?

[Phil Acko]

hi Steve just a quick note i possibly think 50mm is not good enough for 6ft x 4ft id say in region of at least 120mm box section as Ur fitting a double sided light box to this if u don’t mind me say-in what width is the light box mate and you will need big pads of concrete under that i think poss let me know plz 😳 😮

[Stephen Ingham]

hi phil, i think the depth of the box is about 120mm or somewhere near.

any idea on how big the sunken area will need to be?? we are considering hiring a mini digger to help out, easier than doing it with a pick and shovel..

cheers
stephen

[Phil Acko]

not sure off top of head will have to do a reckky wen i get back in office on mon ill keep yeh posted i would guess maybe 4ft deep not too wide maybe 300mm with either stud iron m12 with plates on or sink the whole box section in at once not sure mate?

[Peter Normington]

steve a mini digger would be a waste of money. you only need to dig down about 2 foot, and about a foot square, use a bag of fence post concrete on each hole, pop in the posts and a gallon or so of water, job done.

You could get away without any digging, or foundation, if you use a fence post hammer and beat in the uprights to say 3 foot

Peter

[Phil Acko]

peter what about the wind it will blow over like a kite on a windy day id say at least 4ft without any type of backrakers dont forget its a light box and double sided and perspex and the top will be at least 6 -7 ft off the ground man cmon 2ft hole ha ha!!!!!! (:) peter

[Kevin Flowers]

Steve
is the box portrait or landscape, i wound suggest in between 900mm – 1200mm deep with an area of of 450mm. I would make a frame to match the depth of the sign at a push you could maybe get away with using 4 legs of 50mm x 5mm wall, just space them towards the corners etc. Hope this helps. That depth maybe overkill, i’ve put a 5 mtr high x 3mtr x 1.5mtr sign on 90mm box section with a 900mm hole but a larger hole area which as stood through gales with no problems. Hope this helps

Kev

[David Rogers]

quote Peter Normington:

steve a mini digger would be a waste of money. you only need to dig down about 2 foot, and about a foot square, use a bag of fence post concrete on each hole, pop in the posts and a gallon or so of water, job done.

You could get away without any digging, or foundation, if you use a fence post hammer and beat in the uprights to say 3 foot

Peter

Totally agee, 2 feet deep, well a max of 3 feet – 1′ square hole – couple of bags of quick set.

50x50x3mm wall box section would be OK, a bare minimum spec. and would flex in strong winds – not great but would do the job – but maybe up it to 75mm to 100mm just – might look a bit ‘spindly’ otherwise. Like Peter says, if the ground is firm, but not hard – beating down the post to the right depth is an option, but I wouldn’t try it!!

[Peter Normington]

quote PHIL ACKO:

peter what about the wind it will blow over like a kite on a windy day id say at least 4ft without any type of backrakers dont forget its a light box and double sided and perspex and the top will be at least 6 -7 ft off the ground man cmon 2ft hole ha ha!!!!!! (:) peter

Double sided is not a factor, its the same area as all signs on posts are double sided, A 1/3rd below ground of the height is the normal formula, 6×4 is not that big and I am assuming landscape as steves description implies. 2 foot is adequate, as I said with a concrete surround,

B ad Q sell fence panels and posts that have a larger area and dont even need concrete! HA HA

peter

[Robert Lambie]

i agree with phill.. your gonna need a slimline type double sided lightbox about 4 inch or so deep. try andy at alutrade for advice and a good price… http://www.uksignboards.com/viewtopic.php?t=17386 other good supliers out there but his is closest at hand.

as for the frame the box section should be fine… not the best finish/look but will do the job.

digging, as has been said 2ft deep is plenty. but if you are welding frame yourself, ide add a cross bar on the post feet for stability. not that it is needed but when concrete i set, but helps stability and movement to the point you can do the whole job in one day.
post mix from b&q will be fine for this job, 4 bags at about £4 plus water.

if you are working in a built up area. i.e. buildings around, street lights etc ide suggest hiring a cat scan from a local tool hire source.
will cost you about £5-£10 fr the day but may save your life!
cat scan scans the area you are gonna dig for water, electrical and gas pipes before digging.

if a lightbox, your going to need power out to it…
go to your local CEF and get some armoured cable and run a length of that out to the box and up the "inside" of the leg into the box, to power it.

edit- please note folks, this is based on the sign being only 2ft of the ground.

[Peter Normington]

Buy two round aly posts and ground inserts from ashby, plus fittings and a couple of nice finials to finish of, about £50ish nice good looking job, and no need to do self fabrication

Peter

[Kevin Flowers]

I think that at the end of the day a survey of the area will end up helping with the right decision as to depth etc being made. I planted a notice board 1mtr sq with a top height of 6’6”on 2, 76mm tubes at a depth of 2′ in to a hole of 300mm round drilled with an auger filled with post mix. All was fine for a week or so until the kids decided to swing on it & the company came in one morning to find the notice board tilting over. The tubes hadn’t bent but the concrete & poles had just moved back in the earth. Ended up increasing the hole to 18” square & slightly deeper, not moved since as far as i know. Each fitting job needs to be decided on its own merits & just because common rule is a third of the height into the ground doesn’t mean it is right for every situation.

Kev

[Peter Normington]

as usual Kev, common sense is the answer, but in practice, i would also dig wider rather than deeper, much easier, and add to the weight of the base, rather than the depth, the effective weight of the foundation is what holds up the pillar, not the depth.

Peter

[John Childs]

Two problems here.

One is the stability of the base, and for that two feet is theoretically good enough. Therefore I would go for three. 🙂

Second is the strength of the posts. The biggest base in the world is no good if the posts bend at ground level in a high wind. There’ll not be much force exerted on the end of the sign so higher strength is needed perpendicular to the light box, so I would be inclined to go with 100×50 box section.

I would try to find somebody with an auger. A local farmer here has one mounted on the back of a tractor and would sink me a pair of fifteen inche diameter, three foot deep holes, in about ten minutes. And most of that ten minutes is taken up measuring and positioning. 🙂

Quick, easy, and bomb-proof.

[Steve Morgan]

Stephen,
Take a trip down to your local hire shop and hire some ‘Post hole shovels’ about £10.00 per day. 2 holes about 600mm deep and about 300/400mm square will take about 15 -20 minutes each.
As Rob says you must check for buried cables first.

Steve

[Gavin MacMillan]

Apologies if it’s been said already, I didn’t read the whole post, but 600mm is almost always deep enough.

The rule you would get from the likes of ashby would be 1/3 of the post to be sunk, but in practice as long as the ground is good (read not a boggy marsh) then 600 is plenty. If the ground is so hard that 600 is hard to get to then a less should do.

Pick and shovel? If you dig holes get shovelers (sp?) – Don’t argue, just get them! 😉

G

[Robert Lambie]

pinch bar and a bullet head spade.

[Gavin MacMillan]

your right Rob, pinch bar and shovelers (spoons)

[Martin Pearson]

I would contact someone like Ashby or Sign Connex who make a lot of wayfinding and directory systems to see if there is something suitable available from them before I looked at using box section. You are going to have to get it suitably covered so it stays looking good so something like plastic or powder coating is going to be needed and you are going to need some sort of finial/cap on the top to stop it filling with water which might work out a lot more expensive than buying what you need from someone like Ashby.

As for depth I would have said two foot is suitable as a minimun so Like John would have gone for a little more say two and a half to three feet but as Kenny has already said a good site survey will give you a better idea, bit like house foundations that vary in depth depending on what you are sinking them into.

[Stephen Ingham]

thanks for all the comments and suggestions, much appreciated.

I will have a look at what ashby can supply..the lightbox was purchased from alutrade..excellent products and service..as usual.

cheers
stephen

[Martin Pearson]

Stephen, try Sign Connex as well as they do a lot of post and panel stuff as well as Ashbys.

[Stephen Ingham]

hi all, just a quick update..

doublesided posted lightbox sign manufactured, dug and fitted.

We did end up manufacturing the frame and feet ourselves, as we had all the materials etc laying around and my mig welder was sat in the corner..bored and its more satisfying to know that we made it ourselves

Begun the dig and found it was all LARGE ROCKS so we ended up hiring a mini digger from the hire shop next door..dug about 2 and a half feet down, sunk "feet" into hole and filled with post concrete, left over night and then next day slotted the frame section into the feet, bolted in, wired light box from an existing armour cable that was from an old sign, sorted..

Customer was over joyed with it, job satisfaction

posted the sign on
http://www.uksignboards.com/viewtopic.p … 947#207947

cheers
stephen