Chinook RV Forum

"Skylight" for standard 14"x14" roof hole (removed Air-con)
Page 1 of 4

Author:  Blue~Go [ December 14th, 2015, 12:04 pm ]
Post subject:  "Skylight" for standard 14"x14" roof hole (removed Air-con)

I removed the air-conditioner from my roof around a year and a half ago. I don't have a need for it, but I removed it such that it (or another one) could be reinstalled. This left the question of what to do with the hole. Since a few people have PM'ed me about this, I thought I would share what I did.

To start, I'll mention that the hole for a typical RV roof air-conditioner is the same standard 14" x 14" hole that a typical RV vent fits into (clever!).

When I removed the Air-con, I wasn't sure what my ultimate plan would be. Options included putting a solid fiberglass panel over the hole, putting a solar panel over the area, putting in a marine hatch, putting in an RV roof vent, or...?

So as a "while I think about it," I cut a square of galvanized metal (heavyish roof flashing, comes in a sheet of about 30" x 36" at Home Depot) that was about 19" x 19" (for good overlap) and laid down a perimeter bead of strips of (good) butyl tape, running two beads wide and staggering the corner joints. I then laid the galvanized sheet down and rollered around the perimeter. Done and water tight for the year it was up there (including six months in the Pacific Northwest, so there was plenty of rain).

On the inside, there were some wires in the hole. For the Air-con, one piece of Romex type AC wire (comes over from area above stove, through loom in roof), one Cat 5 type cable and one thin wire (for thermostat, came through roof in loom from overcab area near solar controller). They also ran some DC wire that just "happened" to also go through the hole area (the Air-con doesn't project down in the entire hole area, although it covers it all from above). There is a pair of red/white (positive/ground) DC wires that come up through the roof in loom from the main driver's side wiring run that is outboard of the upper cabinets. It starts over about the center of the couch (fore/aft), and runs over to "the hole." In the hole, it splits two ways. One set of red/white go aft, to the ceiling light near the kitchen (in carpeted ceiling), and the other set go forward to the ceiling light and then to the Fantastic vent. (The ceiling light by the door is on the same circuit but that wire comes from over the door).

For the time being, I just used wire ties to "tame" the wires, and then cut two layers of 1/2" extruded polystyrene insulation and friction fit it into the hole. Then I got a piece of foam board (artist type) from Hobby Lobby (happened to find one with a grey "faux something" pattern that just matched the ceiling carpet), put some adhesive "hook" Velcro on it, and stuck it to the ceiling. That covered up not only the hole, but also the flat spots, etc. in the carpet from the Air-con inside section. So that got me tidy looking, insulated, and water-tight. I went with that for around a year while I noodled options. Here is a shot with the wires and insulation in place. The bottom of the photo is the passenger side of the Chinook. So the "bottom" wires are the Air-con related wires, and the "top" wires are the unrelated DC wires.

wires.jpg [ 275.27 KiB | Viewed 928 times ]

And here is a not-very-good-but-gives-you-the-idea of the foam board velcroed in place. Stayed up just fine for a year, with no signs of going anywhere. Boy, I can't wait to do something about that yellowed Fantastic Vent. I have already painted those "fake wood" strips on the Thin Lites (there is a thread where I posted about it). [Edited to add: Since taking this photo I used some oxy type carpet cleaner on the inevitable dirt spots in the carpet that coincide with the Air-con outlets. So no more grunge look on the overhead carpet.]

foam board inside.jpg
foam board inside.jpg [ 187.64 KiB | Viewed 929 times ]

And here is the flashing on the roof. (The blue tape you see in upper left is where I removed the TV antenna, then filled the holes with epoxy. You can't paint or gelcoat epoxy until it has cured for some time, yet until then it is sensitive to UV, so I put tape over it while it finished curing - it's already totally hard and waterproof, but needs some weeks/months for the epoxy to finish so the paint or gelcoat won't react with it.)

roof with flashing patch.jpg
roof with flashing patch.jpg [ 84.49 KiB | Viewed 929 times ]

Author:  A Rooney [ December 14th, 2015, 12:51 pm ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

wow great post,Question;There has been some discussion on the yahoo board about aerodynamics and Gas mileage,Have you noticed any improvement now that you are incredibly sleek? Thanks Rooney

Author:  Blue~Go [ December 14th, 2015, 12:54 pm ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

So over the course of a year, I noodled various options. The most obvious was to put in a typical RV roof vent (Fantastic vent or other). I thought that if I was going to have something "clear" there, it would probably be a good thing if I could open it to vent any heat. On the other hand, I already have a vent about 12" ahead of that, so don't exactly need a vent there. On the OTHER other hand, that forward vent seems to make wind noise no matter what I do (placement is too close to front edge of roof apparently), so I may want to make that a marine hatch and then put a Fantastic vent where the Air-con was.

I also don't love how the Fantastic vent essentially blocks about 50% of the hole due to the corners not being part of the vent. Another option was a marine hatch, which opens, is low profile, and lets all the light in, but is expensive ($375) and the screen is fiddly. Decisions, decisions (all this time I am trying various things to make the forward vent be quiet...).

Of course if I put a solar panel there, I'd be covering up the Air-con vent anyway...

So anyway, during the course of all this, I found that the Air-con hole was in a place that I can easily gaze at while in bed, and I like being able to look up at the stars, etc. So I decided I wanted to try it as a "clear hole" before committing to blocking it off with a solar panel, a solid (yet removable for Air-con reinstall) patch, etc.

Thus I removed the gavanized flashing top piece (all was well with it, btw, watertight and had never budged, so a worthy temp patch), and instead stuck on a sheet of clear acrylic type plastic from Lowe's. Same basic idea as the metal one, but around 18" square. Two side-by-side strips of butyl all around, with corners interlocked. Put it on, then went inside...

Well oh my, was that nice! Glorious, natural light (Concourse side windows are well tinted), and a perfect view of the stars at night from the bed. It was nice! I there and then decided I was not going to cover the hole with a solid patch or a solar panel (I have other places in mind for those) (plus that would have precluded putting Air-con back). Also, making this clear "temporary skylight" last for awhile would give me time to see if I could get the Fantastic Vent ahead of it to stop making noise, and just to see if I feel I want this "skylight" to be operable or if it's fine to have it fixed in place. But would things get too hot...? I lived with it over this past summer. Temps were only mid- to high-80's, but it was sunny all day most of the time. It might (must) have added a bit of heat, but certainly not nearly as much as the side windows, and it was pretty easy to keep things cool with the windows open and Fantastic Vent open.

At any rate, it's good enough to keep in place for awhile. The only fly in the ointment was that I was still staring up through those wires (ugh), and I also didn't want UV rays on the wires, the sides of the cutout (roof core with a caulking layer "buttered" onto it by Chinook), or the butyl up top (through the plastic). Finally, the other day, I decided enough was enough and to do something better!

The stiff Romex type AC wire, I was able to pull on where it comes out over the stove, and thus pull it into the roof at the hole until it was just flush. It could be pulled back out with plyers if the Air-con were going back. The other two small wires (Cat 5 and thermostat wire) could just lie flush. The DC wires I un-wire-nutted and laid out along the sides of the hole and used FTZ crimps to reattach them in the best "lie flat" position. I could have carved into the roof core if necessary, but didn't want to if I didn't have to (I didn't have to as it turned out). I wrapped the wires in some white electrical tape to further protect them from UV coming through. So that was the wires out of the way.

Then I took a Fantastic roof vent garnish (bought it used-but-looked-new for $5 from an RV parts place) and cut it down so that it would juuuuust almost touch the skylight but not quite. I cut a square out of the previously used grey foam board, and then mounted the garnish plus the foam board on the inside. Ah, much tidier! A nice clean look and no more looking through wires.

Now that the garnish was in place, I went up on the roof and used blue tape and paper on the skylight to mask off the area to the inside of the garnish (in other words, the part I can see through from below). With the garnish in place I could see this clearly from the roof side. Then I taped off the roof just to the outside of the edges of the skylight plastic. This left a ~two inch strip of the roof plastic all around the edge of the skylight exposed. I sanded that, cleaned it, and then sprayed it with two coats of white Krylon for plastic. The goal was to cover up with paint all of the part of the skylight that overlapped the roof (and had butyl beneath it), plus the area between the cutout and the garnish flange (thus protecting the wires and the inside of the cutout from UV as well).

Skylight 2.0 Done!

Here are inside views. This first one is very sun-spotted, but it's hard to get a good view of this in the light without that (at least with my photography skills). But it gives you the idea of how the garnish looks on the inside. You can just glimpse the white-painted (previously "walnut") stripe on the Thin Lite cover.

interior showing garnish.jpg
interior showing garnish.jpg [ 270.88 KiB | Viewed 923 times ]

This is how the sky looks, which I really enjoy, especially at night with the stars (but the nice natural light in the interior is much appreciated too):

interior.jpg [ 247.65 KiB | Viewed 923 times ]

And more of an overview showing the relation to the Fantastic Vent (and you can also see how much more light/view you get without the vent blocking most of it). The holes for the Fantastic Vent and the Air-con (this skylight now) are the same size, 14" x 14".

sky view.jpg
sky view.jpg [ 234.12 KiB | Viewed 923 times ]

So far I haven't had any desire to block off the light coming in. I need all the "help" I can get in the morning :mrgreen: But if I change my mind I will replace the four corner screws in the garnish with snap studs and then I can snap a cover in place. I may also be able to friction fit the square of grey foam board I cut out of the original piece - haven't played with that yet. If a person wanted lights on inside at night plus super stealth, it would be good to block it off so no light leaked out, but I haven't had that need.

Author:  Blue~Go [ December 14th, 2015, 12:57 pm ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

And here is the roof-side view.

roof overview.jpg
roof overview.jpg [ 212.32 KiB | Viewed 923 times ]

Close up:

roof close up.jpg
roof close up.jpg [ 197.6 KiB | Viewed 923 times ]

Skylight is not buckled at the edges, that is just a touch of grey butyl squeeze-out near the corners making it look that way. BTW, there was some very slight sagging of the roof from the Air-con, so I don't mind having that hunka weight off the roof (if I put it back, I'd likely add some reinforcement somehow; otoh, it was up there 14 years and nothing drastic happened).

In time I may upgrade to 3.0 :D Not sure yet what that will be. Likely either leave it the same (with possible substitution of tempered acrylic), put in a marine hatch, or (if I have to) put in a Fantastic Vent and put the skylight where the Fantastic Vent is now (to take care of wind noise, if I can't do it some other way; but that would move the sky view to a less desirable position in the rig)(I think I'll be able to get rid of wind noise somehow).

Author:  Blue~Go [ December 14th, 2015, 1:09 pm ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

A Rooney wrote:
wow great post,Question;There has been some discussion on the yahoo board about aerodynamics and Gas mileage,Have you noticed any improvement now that you are incredibly sleek? Thanks Rooney

Hi Rooney,

I haven't really noticed, but the thing is that I haven't really checked that closely. And it seems there is always something "different" about the situation. I'm towing or I'm not towing, I'm going 55 or I'm going 70, it's mountainous or flat, there is a headwind or not, etc. I'm sure it can't have hurt, but on the other hand it's a small part of the "big barn" we are pushing through the air. It would be fun to know for knowing's sake, but in my case wouldn't really affect how I use the rig.

I would guess that little rail around the perimeter of the roof might be a factor (lightweight but lots of disturbance). But then again, small part of big barn. I actually thought about removing that railing, but I often use the part on the overcab (I kneel on the overcab, hold onto the railing, and reach down to clean the front of the overcab, which as you know is a bug magnet!)

Mostly I'm glad to have that 100+ pounds of Air-con off the roof, since I didn't use it anyway. I like the sleeker look a lot. And I really like the skylight! I figure if there is a specific time I need Air-con for a few weeks (dive trip to Florida in summer, say), I'll either get a cheap window unit and cut some plexi or plywood to fit it in the passenger side cab window (van folks do this), or I'll get one of the free-standing "floor" units and put it between the driver/passenger seat and run the hose over to a small plexi insert in the passenger window opening. I'd be plugged in in any case as there would be no way I'd "live" for weeks with the generator running to run an Air-con :shock: Too, I could put the Air-con back, but my guess is I never will (but maybe next person will want to, or I'd do it for a buyer).

BTW, my Air-con bolts were not loose-loose, but they were not as tight as I'd have wanted them if I were keeping the Air-con in place on the roof. Might be something for folks to check.

Author:  Blue~Go [ December 15th, 2015, 10:46 am ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

I thought I would add a photo with the wires somewhat labeled. Not sure every year/model would be the same (I was in contact with someone who has a '94 and the Fantastic Vent was nearer the kitchen and the same wires were not in the Air-con hole), but maybe this will help some of us.

Since the Air-con unit doesn't fill the whole hole, like a vent does, there was room for Chinook to run these wires through it.

wires, labeled.png
wires, labeled.png [ 494.17 KiB | Viewed 903 times ]

Author:  kdarling [ December 15th, 2015, 3:27 pm ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

Great timing! I was just about to ask if anyone had made that into a skylight.

It looks great!

Your idea of painting the skylight edges to look like a frame is inspired, as well. Nice job!!


Now, we just need to shame you into painting that old faded yellow Fantastic fan trim inside, too :)

Author:  Blue~Go [ December 15th, 2015, 6:23 pm ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

kdarling wrote:
Great timing! I was just about to ask if anyone had made that into a skylight.

Glad to know it may be useful to someone.

kdarling wrote:
Your idea of painting the skylight edges to look like a frame is inspired, as well. Nice job!!

Thank you! Mostly the painting was to keep damaging UV rays off of the underlying butyl and the edges of the roof cutout - plus the DC wiring running along-side - but it does look a bit more finished, as a bonus.

kdarling wrote:
Now, we just need to shame you into painting that old faded yellow Fantastic fan trim inside, too :)

Ha ha, I know, right? I would have done that already but that vent's place in my rig is not yet assured, because of the annoying wind noise. Still, for the amount of time I've been looking at it, I perhaps still should have. Didn't look quite as crappy when my "skylight" hole was full of wires :D Once I know that I can eliminate the noise....

Author:  Scott [ December 21st, 2015, 6:37 am ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

Awesome idea. So awesome, in fact, that I copied you… :lol:

I used my aircon briefly but decided to remove it for a few reasons. 1) The vents and control panel on my 21-year-old aircon were unsightly, 2) it drew a ton of current and provided little cooling, 3) it lost a battle with a tree branch while under the care of the previous owner, so the plastic cover was cracked and needed to be replaced, 4) I really, really like natural sunlight. So I disconnected everything, pried it off the roof, and slid the 96 pound Coleman unit down a long ladder at an angle.

So in copying your skylight idea (thanks again, Blue) I cut a piece of plate glass to cover the 14 x 14 hole, but my roof wasn’t quite flat enough to seal it. Plan B was to use a more flexible piece of cast acrylic, which I sealed with butyl and some stainless screws. The natural light that comes in is soooo awesome. It’s just fantastic. The only downside is the indented signature in the headliner from the aircon vents, but this will be corrected soon I hope. And since changing to LED lighting, I no longer needed the two hideous yellowed non-thin incandescent light fixtures on the ceiling. With the fixtures and aircon vents gone, it actually feels roomier.

Since my Premier doesn’t have a thermostat for the aircon, the only wires in this location were those in the Romex cable. And since my microwave is a distant memory, I just pulled the Romex back through the microwave bay until it was flush at the aircon hole, where it can easily be pulled back if needed for future service. Then I attached the Romex service loop to the wall of the microwave bay. Lastly, I labeled the cable to allow for a “painless” re-installation if ever needed. Naturally, the cable is disconnected at the load center.

Once my project list gets down to a more reasonable size, I’ll trim out the hole with matching oak, but for now I just have a standard white garnish trimmed to the correct depth.

Also maybe worth mentioning: my 14 x 14 hole was sloppily cut from the factory. It was out of square and undersized. So before installing the skylight, I took a laundry basket lined with an old sheet and jacked that up to the ceiling to cover the hole from the inside. Then I taped the perimeter of the hole on the roof to protect the gelcoat, and squared it up with a circular saw. I lowered the laundry basket and had nearly nothing to clean up. Fun stuff!

Author:  Blue~Go [ December 21st, 2015, 1:32 pm ]
Post subject:  Re: "Skylight" for standard 14"x14" roof hole (removed Air-c

Great to see your addition to this topic/thread - glad you joined in. It's good to have information for various year models, too.

Naturally we want to see photos :D Especially when you get your wood trim up!

On mine the hole was just about perfect for the 14" x 14" vent, but I probably just lucked out. Great technique with the laundry basket. I'm happy to put in any amount of time prepping vs. cleaning up dust (ugh). I've often just taped up plastic on the inside, but the basket is a great idea because sometimes there are surfaces that don't want to be adhered to. Or more dust than plastic will hold up. Or the wind wants to suck the plastic into the saw blade...

Plate glass sounds interesting. I was thinking I'd go to tempered acrylic when I change, but real glass would be interesting presuming it has some non-breaking factor (I just used generic Lowe's panel since I had no idea I'd like it enough to make it a longer-term thing, so I'll likely be replacing the top piece at some point, although it's still fine looking now).

Page 1 of 4 All times are UTC - 8 hours
Powered by phpBB® Forum Software © phpBB Group