Channe letter wiring running through expansion joints

[Big Rice Field]

The landlord in Florida wants the wiring run not behind the wall, but on the facade in what he calls "the groove" which I see as expansion joints. The idea is to run the wire and cover it in a "weatherproof sealant".

In my 25 years as an architectural & Electrical Sign Designer, I have never seen such an installation and I question its viability, and if it is in accordance with electric code.

My guess is the "weatherproof sealant" should be aerospace-grade RTV which is like rubber and can hopefully withstand thermal expansion and contraction of the expansion joint "groove".

Can anybody shed some insight on this? Thank you in advance.
Clueless in Phoenix

 

[signage]

First of all are they expansion joints or scores for controlled/stress cracking?

Next are they deep enough for the correct bending radius for the wire size used?

Also does it have sufficient clearance for proper wire protection device at channel letter penetration?

I would also think that the wire has to be approved for outdoor use (adequate UV rating), I personally wouldn't do it because if it failed and caused catastrophic damage they would most likely find you responsible for the damages.

 

[Gino]

I would think it would be alright, as long as you put it in proper conduit. However, that will look pretty stupid. Plain wiring covered with caulk, nope. Some people need to just stay outta the way. Let the professionals figure it out.

 

[Notarealsignguy]

I dont think caulking over the wiring would be code approved. You have to take heat into consideration when you run in conduit. The sealant would insulate the wires and potentially cause overheating. Plus, the sealant wouldnt be approved for flammability or the use that they are asking for.

 

[MrPrinter]

put the secondary wiring in watertight flex (w/ proper connectors)in the groove and should be ok, keep client happy, and pass inspection

 

[Big Rice Field]

The landlord in Florida wants the wiring run not behind the wall, but on the facade in what he calls "the groove" which I see as expansion joints. The idea is to run the wire and cover it in a "weatherproof sealant".

In my 25 years as an architectural & Electrical Sign Designer, I have never seen such an installation and I question its viability, and if it is in accordance with electric code.

My guess is the "weatherproof sealant" should be aerospace-grade RTV which is like rubber and can hopefully withstand thermal expansion and contraction of the expansion joint "groove".

Can anybody shed some insight on this? Thank you in advance.
Clueless in Phoenix

Gentlemen thank you for your professional suggestions.

 

[Johnny Best]

That is probably precast concrete and that "seam" is where one is laid on top forming the part they want the wire run.
You should us liquid-tight conduit and secure it with proper retainer clips. Paint those the color of wall. You can't run exposed wires with chalk over them in that "seam". You would have water coming down that wall and puddling where you have your gobs of chalking to cover the wires.

 

[Big Rice Field]

First of all are they expansion joints or scores for controlled/stress cracking?

Next are they deep enough for the correct bending radius for the wire size used?

Also does it have sufficient clearance for proper wire protection device at channel letter penetration?

I would also think that the wire has to be approved for outdoor use (adequate UV rating), I personally wouldn't do it because if it failed and caused catastrophic damage they would most likely find you responsible for the damages.

Likely scores, but hard to tell from site survey phots. No autocad architectural elevations to work off of.

 

[Big Rice Field]

That is probably precast concrete and that "seam" is where one is laid on top forming the part they want the wire run.
You should us liquid-tight conduit and secure it with proper retainer clips. Paint those the color of wall. You can't run exposed wires with chalk over them in that "seam". You would have water coming down that wall and puddling where you have your gobs of chalking to cover the wires.

The seal is not hard chalk but rubber like silicone.

 

[Big Rice Field]

That is probably precast concrete and that "seam" is where one is laid on top forming the part they want the wire run.
You should us liquid-tight conduit and secure it with proper retainer clips. Paint those the color of wall. You can't run exposed wires with chalk over them in that "seam". You would have water coming down that wall and puddling where you have your gobs of chalking to cover the wires.

I am not sure of the dimensions of the groove and not sure if liquid-tite conduit will be flush to the fascia after installation. The landlord wants the groove to disappear and to be finished just like the wall sections above and below.

 

[Texas_Signmaker]

I've never seen that type of wiring done. If they don't want penetrations behind each letter then they need a raceway. Maybe the raceway could hide the grooves that the landlord is so worried about. Some people are just too nit-picky about things. (the landlord)

 

[Big Rice Field]

Liquid-tite conduit is only 1/2" in diameter. Stuff it in the groove, retain with clips, and then cover it with potting to make the groove disappear.
SO when that store closes the next tenant will have fun tearing that all apart.

 

[signage]

The landlord wants the groove to disappear and to be finished just like the wall sections above and below.

Ask the Landlord why he let the builder get away with this then! It's not the sign fabricator/installers job to change building standards or attempt to correct what they don't like visibly. I would tell the Landlord I want a million dollars and see if he gives you it! :-{)

 

[Texas_Signmaker]

Ask the Landlord why he let the builder get away with this then! It's not the sign fabricator/installers job to change building standards or attempt to correct what they don't like visibly. I would tell the Landlord I want a million dollars and see if he gives you it! :-{)

Yup, and if he agrees to do it the landlord will pick apart the job he did. Now he's gone from a sign installer to exterior wall finisher.

When people start asking me to do stuff outside sign installation I stop them right in their tracks and say, "We're a sign company that can install the sign, not a XXXX contractor. You'll need to call those professionals"

 

[signage]

You could always ask you local electrical inspector if he would approve it, but then again he would be liable if something went wrong and that was found to have caused the issue. I wouldn't even run liquid tight in that grove. I am not a structual engineer nor a member of the electrical inspectors group, but it doesn't seem OK to do. Like Tex said make a raaceway and be done with it or individual penetrations!

 

[Big Rice Field]

I would resort to a raceway too. but the landlord will not allow raceways. I was taught years ago that raceways were a last resort from an apperance point of view. They cast shadows and are ugly. But sign people love them, especially installers.

 

[Big Rice Field]

Again, gentlemen, I appreciate your information and suggestions and professional opinions. Thank You...

 

[Texas_Signmaker]

How come he doesnt want the individual wire penetrations? The letters will have 3-4 fastener penetrations at least to hold them up, what's one more?

 

[Jester]

As a landlord myself, I understand his desire to preserve his walls as much as possible. When the tenant moves out all of those holes will need patching, and patches are never the same appearance or as sound as the original wall.

The vee-shaped "detail strip" cast into in a typical tilt-up wall panel is not deep enough for 1/2" conduit to fit flush.

If it is a panel joint, in order for conduit to fit flush you would have to strip out the existing caulk, push back the foam backer-rod, install the conduit, and re-caulk using a material similar to the sample I reference below. As a sign company, this is WAY out of your area of expertise!

Back to your original question, if you do decide to embed the low-voltage wiring in the vee-groove, an architectural sealant like this would be the correct product to use:
https://usa.sika.com/en/constructio...ral-sealants/polyurethane/sikaflex-15-lm.html

 

[GB2]

I think your best option would be to form some aluminum components to join the domino and the D at the top, where they are closest together. This would be only a small 1x1 channel painted the color of the building, which would then technically become part of the channel letter assembly and you would then run the wiring between them inside of that and it would be practically invisible and a legitimate construction.