• foam panels ?

    Posted by Terry Bull on January 5, 2003 at 7:13 pm

    Id like to ask some advice about foam panels …
    A 20ft x30″x5mm sign fitted within a paneltrim frame keeps blowing out
    The panels were routed with a half lap join ,fitted with a hanging rail and bridging pieces were stuck to the back whilst installing.
    The building its fitted to is corregated so it seems the wind gets behind it

    I have replaced broken panels before and it has happened again
    A friend has suggested that I ccould force 10mm in without
    a rail -the 5mm just seems to flap around
    whats your veiws ?

    Also I have a 3m x 2m x 10mm facsia sign which I want to fix to a shopfront covered in upvc cladding and not wanting to use a frame wondered the best way to apply without fixings being too obvious


    Robert Lambie replied 21 years, 6 months ago 8 Members · 19 Replies
  • 19 Replies
  • Fat Bob

    January 5, 2003 at 8:44 pm

    Hi Terri

    I have overcome this problem in the past by putting a hanging rail top and bottom
    and on one occasion the sides. the other thing is to make sure the joints dont drift apart
    (you can by little perspex locks which hook over each other) once you have bought a couple you have a pattern to make your own.

    On one flexi face we done we had so much trouble with the wind getting behind we backed the whole frame off like the back of a light box.

    The panel Be careful…. Some clowns who put up this cladding stuff have fixing it to absolutley sod all off to a fine art. If thier are going to be a lot of dark ares then it will catch the heat more than white and it may Buckle this of course is no where as bad as 5mm.

    Hope this is of some help Regards…FB

  • Sparky

    January 5, 2003 at 8:44 pm


    I’m a lot newer to this game than you, but ….

    Could it be that the bottom edge isn’t sitting deep enough into the panatrim ?? I know that when the board has to go in from the front it’s not held in by a lot (15mm ?), the only ideas I have are ….

    1. Cut the boards to fit right to the bottom edge & enter from the end of the frame

    2. Brace the back of the 5mm board with strips of foamex glued (to stop it bending with wind pressure)

    3. I have had to replace a couple of old signs that have been silicone sealed right around the inner frame edge, not sure if it helps but they’re a bugger to get out so it’s possible ???

    Other than this, I got no ideas m8. Done quite a few big ones & only lost one, but that was one of my first on a corrugated building & I didn’t know about joining the panels 😳

    hope it helps !


  • Phill Fenton

    January 5, 2003 at 9:00 pm

    Like Bob – I have in the past fitted lower rails as well as hanging rails in areas prone to storm damage. If you fit a lower rail as well it is virtually imposible for the panel to blow out. It would need to physicaly break first whereas when fitted with a hanging rail – simple flexing of the panel is enough to blow it out. A good join where the seperate panels meet is also a must. I’ve used packing in the past and screwed throught the front panels and into the cladding. The panels can still expand lengthways out from the join in hot wether so this doesn’t cause a problem, and if you counter singk the holes where the screw heads show on the panels you can cover these with little circles of vinyl to make them virtualy invisible from ground level. Done this way – the panels will almost certainly not blow out again – good news for the customer – bad news for the signmaker who loses out on repeat business caused by “Storm damage” 😉

  • Martin Pearson

    January 5, 2003 at 9:02 pm

    Terry when I do these jobs I never attach the frame directly to the building. What I mean by this is I cut a sheet of 4mm or 6mm external ply the same size as the panatrim frame. The ply sits between the building and the frame preventing the wind blowing the panels out. I have tried to block up the holes behind the sign frame in the past but it takes ages and is awkward to do. I find the plywood works a treat and is a cheap method of preventing this problem. When I visit customers with this type of building I always explain the possible problems and so if my estimate is a little dearer than someone elses then they know the reason why.

  • Phill Fenton

    January 5, 2003 at 9:12 pm

    I have a different theory Martin 😎

    I believe what happens is not what most people commonly believe. It’s not a case of wind getting in behind the panels and blowing them out. What actually happens is this:-

    High winds passing over the front of the sign panels create an area of low pressure. Behind the panels there is little wind movement – therefore the air pressure is higher. The pressure difference between the front and rear of the panels is what causes the panels to “Blow out” – in effect they are sucked out by the lower air pressure caused by the high wind passing over the panel. This is exactly the same effect as what causes “Lift on an airplane wing, and “Downforce” on a racing car.

    Martin – Your solution to prevent the ingress of air behind the panel actually increases the likelihood of the panel blowing out as it creates an increased differential air pressure.

    I know all this because I was a scientist in a previous life 😮

  • Fat Bob

    January 5, 2003 at 9:26 pm

    Hi Phil

    Iam not a scientist but i agree with you 100% me old china


  • Martin Pearson

    January 5, 2003 at 9:38 pm

    As I am not and have never been a scientist I can not argue with Phill and his theory on why sign panels blow out.
    As for the method I use if it makes the panels more likely to blow out then it must also make me extremly lucky as well. I have used this method on quite a few buildings now, some of which the panels had repeatedly blown out on and as yet not a single panel has blown out despite some really bad winds.
    Now if I can only apply the same luck to picking the lottery numbers I’ll be quids in !!

  • Terry Bull

    January 7, 2003 at 12:22 am

    Thanks for the comments
    All your advice seems to be right
    ..im tempted to put a rail at the bottom as these panels are fitted from the side and I can see the logic but its still a gamble with 5mm

    Another thing I have thought of is to use thin gauge white faced allunium sheet
    with 6mm ply behind, alternate the sheets and screw the ali to the ply at the joins and top and bottom as its fitted -the ply could have a rail fitted ,though the metal wont expand and contract like plastic so perhaps just make it a tight fit . the two materials screwed together must be more stable than the plastic .
    What do you reckon ?

    With regard to fixing on the cladding a good point being make i’m going to offer the sign but not the fixing of it -see what happens ,if they like the sign hopefully theyll find a way to fix it
    i’d sooner sleep at night


  • Fat Bob

    January 7, 2003 at 6:18 pm

    Hi Terry

    You are on about the panels being 5 mm youll be supprised the difference 6mm would make put strips top and bottom I dont think youll lose it.

    As for the supply only great idea if you get away with it I would lay odds on my chance if it were me…….Best of Luck mate.


  • Martin Pearson

    January 7, 2003 at 8:29 pm

    Hi Terry, I would forget the ally sheet screwed to ply as you will be able to see the fixings which spoils the sign and defeats the object of using a frame. As for supply only in an ideal world we would all stay in our workshops and never go out fitting but I think the customers automatically expect you to fit the signs as well as produce them, if you offer him a supply only price then he might lose confidence in your ability to do the job at all so be careful. We always offer the customer a fitted price automatically unless they have asked for supply only.
    If they are a bit hesitant about the price we will tell them that we could supply it for them to fit at a cheaper price but the cheaper price is always more than than just the installation cost so it looks like we are fitting it for a reasonable price.
    Have a look about locally to see if you can see how other sign companys have tackled this sort of job, something else to bear in mind is the make of foam you use. The cheaper foam boards tend to have more air in their make-up which makes them lighter and easier to bend.
    You could always glue/tape strips of either ally or ply to the back of the board to give it a bit more ridgidity.

  • Robert Lambie

    January 8, 2003 at 12:05 am

    Ok here’s my solution for what it is worth. And don’t laugh… not a snigger, or i’m gonna go in a huff…

    Ok after reading martins reply I thought excellent idea martin. Nice one mate. 😉
    Then I read phills Scientific explanation and thought the same… brainy git.. Well seeing he’s a Scotsman. 😉 😆

    On the subject of what to do…
    Forget the aluminium. Use rynabond or allucolour. You can get them from europoint display and amari plastics.
    Both are much cheaper than aluminium. And come 3m x 1.5m sheets.. cost about £75 and come in a range of coloured finishes. Its extremely light and easy to work with. If you don’t know what it is its basically di-bond with another name.
    What we tend to do is use sheets of .75 inch thick sheathing ply. Cheap stuff. And screw it directly onto the face of the building. You can also use some silicon on the rear of the sheets before hand. Fixings? We use either tech bolts or broad threaded self-taper screws.
    Take your silicon and smear it in diagonal lines all along the wood.
    Lift your rynabond sheet up into place and put some keeper screws in place round the edges.. Pressing form so as to get its nice and flat 7 give the silicon a good grip, then make the screws all about .75 inches in from the side all round to hold it in place… if you have a join you can use a double sided tape… and then put a couple of screws through the face in the middle
    Take 1” x 1” aluminium angle and cut and mitre it to length. Screw this from the sides all round the fascia.
    This will hold tight the whole job, sealing it and giving a lovely finish to the job.

    The benefits are:
    The sign has a glossy or a silk finish to it.
    It is easily wiped clean.
    It can’t be smashed with a brick
    Because the signboard is screwed and siliconed onto the building it has no play to be blown out.
    Using 2-3mm rynabond will prevent any flex in the sign due to how rigid the metal is.
    You still have a properly finished sign because you have used the silver angle all round.

    You will also be able to sleep well at night! 😉

  • Martin Pearson

    January 8, 2003 at 12:54 am

    Robert do you treat the sheathing ply in any way ?
    The reason I ask is because I have seen it used to board up windows in empty buildings and after a while it seems to warp and de-laminate.

  • Robert Lambie

    January 8, 2003 at 2:05 am

    crozote the wood martin or use somthing the same… to be honest though
    it does get sheltered very well by the trim and the face. the only water getting in is maybe some drizzles running down the back… but thats easy to avoid.
    once the sign is completed and all the trim on… just run a line of clear silicone along the top of the trim in tight to the wall and it seals any water running down the back….

  • Neil Kelly

    January 8, 2003 at 9:37 pm

    Phill love the science but not sure if it stands up the low pressure on the back of the ply in the voids of the corrugation would not transfer to the rear of the panel and the gap between the panel and the board would be still air and arguably a partial vacuum resulting in sucking the panel back resisting the outward pulling forces of mother nature.

    I haven’t used a ply backing but I wood have to agree with Martin if you were intent on using panatrim that this wood be a good option but may prove to add weight to the cladding and eventually cheaper woods might rot and fail. I have fitted top and bottom rails and used a deep storm extrusion on very exposed areas. But joints however good at first always seen to be a problem on signs made of 3 or more panels. on one sign fitted 8 years ago 55′ x 4′ I started with panel locks as Bob describes at the top but they eventually failed, we ended up putting a 4″ wide overlap strip behind the joints and using 3 mm countersunk machine screws drilled and tapped 4 per join through the face with the vinyl dots to hide them.

    Touch Ally its still there Today

    But less of my blurrb I HATE 👿 Panatrim and everything that looks like it.

    Terry Foam is cheap and light and I wouldn’t use it on a sign of 20′ because of the problems that you have encounterd a cheap extruded acrylic would be heavier and may not have failed in the same circumstances and this is always a good argument and justification for a higher price when quoting I often throw in a cheap alternative when pricing a job to compete with an alternate budget quote but always make the customer aware of any possible weaknesses they tend to respect your experience and the decision is theirs.
    then if we do have a mother of a storm your covered to some extent

    My Solution Bin The Trim (:) (:) (:) (:) (:)
    fit an Aluminium Tray sign with 50 mm returns 😛 😛 😛 😛 😛
    Rob can we have some hearts in the emoticons I would have used them here if they were available + Valentines is on its way. I looooove ally trays because they are warm.

    😀 Benefits:

    No face fixings
    nice sleeve joint’s
    powder coated finish
    takes vinyl like a van
    cost is the only fractionally more than panel and frame
    light weight
    easy and quick to install
    last forever

    😥 Drawbacks:

    No visible frame to act as a border ( but a vinyl stripe around the perimeter can add the same effect )

    Rob: Re Using wood and ally beading for a long term solution I would have thought the screws fitted into the open end of the ply will probably come out as the wood rots and you could loose the trim and expose the edges of the silicone fixed panel.

    I once fitted A 2400mm x 1200 mm Oval to a cladded building using 5 mm acrylic fixed with loads of Dow Corning silicon to a 1″ marine ply Oval . I used a rear fixed rail to attach it to the building and the acrylic was bonded on the bench and left over night. It didn’t last 12 Months the silicon failed and the face fell of the front.

    never did that again I generally don’t use wood now if I can use metal.

    well that’s my twopeneth

    by for now Neil……………………..

  • Fat Bob

    January 8, 2003 at 10:20 pm

    Hi Guys

    I think you have come up with the best soloution so far But we must assume that Teri is having to pay for this out of his own pocket and does not wish to spend serious money
    maybe. What do you think Teri.


  • Terry Bull

    January 9, 2003 at 10:15 pm

    Hi All
    first off I must say i’m really impressed and appreiciative to everyone taking the time to help me with this problem
    Robert if I was starting from scratch with this job then I would certainly consider your method it seems like a bulletproof solution and one that I will bear in mind in the future .

    Neil the trays that you mentioned I never thought of but they sound attractive ,I would apprieciate some more info regarding suppliers please

    As one man and a brush ( who said mickey mouse ) firm I usually try to avoid these types of signs cause I cant fix alone but with existing customers I sometimes get caught

    Fact is the frame is on the building ,fitted by the customer ( I got out of that one Martin /Bob )
    I delivered and they fitted it when the building was first erected and the landlord seeing it asked incoming neighbors to make their signs the same size etc so forming a band along the front of the building
    The neighbors have trim and panels too -and they’ve broke

    Looks like a legacy im stuck with, so does this sound reasonable in the circunstances
    9mm foam half lapped joins ,no rails cut as deep as possible to fit the frame and slid in from the end
    If its too thick perhaps I could route a couple of mil of the rear of the panel ..

    Please bear with me – thanks

  • Mike Brown

    January 9, 2003 at 10:38 pm

    Neil!…I’de be interested to know more about the trays too please!

    Could you see Rob (admin) about getting some images up on here and a few details too? – Price, suppliers, fittings, etc. etc.

    would appreciate it! 😉

    more soon


  • Martin Pearson

    January 9, 2003 at 10:55 pm

    Mike, Ashby do sign trays as well as post and panel stuff, give them a call as they have brochures covering sign trays. I like them and would use them more often but the people round here wont part with their cash, everything has to be as cheap as possible. Perhaps 2003 is the year that I can manage to educate a few of them !!

  • Robert Lambie

    January 9, 2003 at 11:05 pm

    I agree with you Neil, wood isn’t always the solution. But it does have to rot before it will give.
    In casing it as I have said does eliminate the bulk of any rainwater. The face and the top are sealed.
    Over the years of using this method I have not had any complaints other than that of what you have just mentioned about the rail coming away. However I do use a different method than I did a few years ago.
    If the wood is fixed to the wall with silicon and screws it should stay put regardless of moisture.
    The face covering, metal, Perspex etc can be screwed round the edges like I said and silicon put on the rear. belt and braces and no trim yet.

    the trim round the sides is just to seal and give a nice appearance.
    Like I said I did have the bother you mentioned about the trim coming away. But I have been using the method below coupled with silicon only on the bottom rail.

    The screws are 2.5 to 3 inch long. Put in at angles shown. Now if the wood expands those screws at the angle hold simple because of the angle they are put in. the down force of the trim coming away, pulls on the screws. But because of the angle they actually act a little like a dovetail joint. Holding strong even if slightly loose… if you have silicon in there. it again should still stay put.. so far ive not had problems… touch me head

    All this said mate, I do appreciate what you have said… and to an extent you are right. Wood will only last you “X” amount of years….

    With regards to the oval do you mean you had bent a trim round the oval pinning it all round that came away?..just curious 🙄

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