Sign with west exposure

[dlcw]

I've been asked by a local business to create them a large sign (8'x5'). The problem is the sign has a extreme exposure to the sun for the entire day. It will be mounted on a shed roof that overhangs the sidewalk where the business is located. So it's going to have the heat from the roof to contend with as well. Here in northeastern WA state we have some really intense sun for 3.5 months a year with sunrise at 0430 and sunset around 2130. It really beats down. Winter sun is just as intense (when we ever get any), but the length of time for sun exposure is much less.

Can any of your sign makers recommend a product for this sign as well as paints and sealers that will last for many years?

[dakers]

if the sign is vertical and you are routing it and you are using material options that are common use on this forum like hdu, wood you have these choices: acrylic latex, oil base house paint, two component acrylic polyurethane, acrylic aggregate.
the longest lasting finish for hdu sign is probably smalt and gold leaf if you have the budget. it will outlast any paint in any condition.
other than that if you have the budget for using all two component auto finishes with clear coat will outlast other paints.

However, it is ok to just repaint the sign when needed and choosing fade resistant colors help.

I used to work on making Firestone Store signs back in the 60's and they were all porcelain enamel and big. they seem to last forever in the weather, then did alot of acrylic signs for Goodyear that were very weather resistant but every type sign seems to have pros and cons about durablity and repairablity.

HDU has worked well for us.

[joewino]

Here in Texas we deal with the heat constantly. What we have found that works best within a limited budget (always a limited budget) is HDU and 100% acrylic paints.

Porcelain enamel will last forever, but is cost prohibitive in most cases.

Wood products would fail over time in your area and metal would peel and/or fade unless you used a two part automotive enamel.

Since we do a lot of dimensional signs in HDU that is what I am partial to, and seems to work best for us. I would suggest a high density HDU (20#) and several coats of a premium acrylic paint. Darker colors fade more quickly, so several extra coats help to slow the process. Do not clear coat.

[dlcw]

It looks like 20#HDU might be the choice to go with. Acrylic paint seems to be the coating of choice.

The customer is building a metal support to mount the sign on (I can give him the design specs). Would it be prudent to use something like MDO is a backer to the HDU to provide stability and rigidity to the HDU? Glue them together with epoxy? Or is the expansion/contraction rate significantly different between HDU and MDO that it would cause problems? Your experience?

Thank you both, very much, for the info! :D

[dakers]

I can only address wood and hdu,
in our area since the hdu lasts longer than wood we prefer not to use any glued/ laminated backing that rots or will separate over the life expectancy of the sign because of different extraction / contraction rates or moisture, drying, warping unless it is easily replaceable without damaging the hdu by using mechanical fasteners. if the budget allows the proper thickness and density hdu that can be the best option with the properly designed steel frame you mentioned but hdu is often bolted to wood surfaces with great long term success using the right wood. some use the alumacorr backing with glue and that works for them. I just do not have any good experience with any backing that is glued or laminated to hdu over the long term ( 10 + years ) but am waiting for others to give their experience to learn from as well.

[RossMosh]

Corian deserves a shout. It's very durable and heat/weather resistant.

[bleeth]

If I have this right you said it was going to be mounted ON a shed roof. Although I lived on the other side of the pass from you I think you not only have to be concerned about the sun in the summer but also the winter snow and melt as well as some really good wind. In any anchored frame you want to minimize the ability for airflow behind it building up a high pressure area.
Guys like Dick have 1000 times more experience then me in sign mounting but I think I would go for a pretty beefy aluminum U-channel surround and a couple cross pieces of flat bar for stability too. As far as whether it is better to bolt it close or off standoffs to the roof can vary depending on the roof material and condition. A half a dozen Carriage bolts will probably do just fine if you can get to the underside. 1/2" lags if you can't but you want them to go into trusses 3 to 4 inches if you can.

Go Huskies!:)

[dakers]

i find it challenging to think. there are so many ways to install things.
if i wanted something light weight i could handle with me and another guy and a couple ladders and was simple
i would probably buy a 5x8 alumacorr and then bolt a 2x2''x 1/4'' angle around the edges to make it like a pan that the 2'' hdu sign would drop into. would probably install the frame then put the sign into it after the frame was installed on the roof. or if i wanted to rent a crane i would just have it lifted in place. i would use long stainless steel deck screws through the edge of the angle into the hdu every 6'' top and sides. then use two 1-1/2'' angles vertically to hold the sign and to be bolted to something solid on the roof. i can survey the roof and figure the spacing needed for the vertical supports to hit something solid if possible. i would see how other signs are mounted on the roof and try to duplicate that if they have been done right so all signs are the same. then put the two back brace angles on that would attache to the roof and the vertical angles.

would use alot of silicon to keep roof from leaking
the aliumacorr would take any wind pressure from the rear and be light weight too.

would keep the bottom of sign high enough to allow snow issues.
but if other signs were installed differently i would change everything,
also could make a 2''x4'' treated lumber frame and use the angle for attaching to roof. and i am sure there are hundreds of other methods,
i want to learn how you would do it so post if you have time.

[dlcw]

Dick, your drawing is exactly what the business owner and I had in mind. He will be fabricating and installing the mounting system to the roof with his crew. He will then take the sign I make and attach it to the mounting system. He and I will work together to coordinate the sign and mount fabrication so they fit together when it's time.

Currently there are no other signs on the roof he will be mounting to. First come, first served....

Thank you again to everyone who's responded. You've given me lots of things to think about and plan for. I will post pictures when it's done.