Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
 
Old 10-06-2019, 09:50 AM   #1
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 6,995
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
Plastic ceiling?

I'm thinking about putting rivnuts into some of the existing rivet holes in my hat channels (either 8-32 or 1/4-20, maybe every 8" or so) and then mounting 0.06" sheets of HDPE plastic (https://www.eplastics.com/HDPENAT0-060SR48X96) as the new ceiling using nylon bolts (https://www.mcmaster.com/plastic-bolts) to maintain the thermal break. Aesthetics notwithstanding, would this last very long? Would gluing the panels as well be necessary or even help? The warning that these nylon bolts absorb water and expand seems to be a concern. Those PEEK screws seem like they might work better, but at $5.50 a pop it's not going to happen.

__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Old 10-06-2019, 10:38 AM   #2
Bus Crazy
 
plfking's Avatar
 
Join Date: Jun 2016
Location: N.C.
Posts: 1,136
Year: 1997
Coachwork: Bluebird
Engine: DT466E
Rated Cap: 34
I wanted to use perforated vinyl soffit for my ceiling, but couldn't find any without the molded-in ridges. Sagging between the 28"-32" span of ribs was a slight issue as well.....but solved by running a screw into the insulation. Definitely test it out.

As far as plastic bolts absorbing water, I personally don't think interior condensation wold be enough to affect them.
__________________
Don

The Busted Flush
plfking is offline   Reply With Quote
Old 10-06-2019, 01:39 PM   #3
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 6,995
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
I think testing this is a good idea. I'm going to try putting a small-ish piece of HDPE up on my ceiling with rivnuts this way and see how it holds up. It looks like that plastic bolt place I linked has glass-filled nylon screws that are twice as strong as regular nylon and only cost $1 or so each. I would only do this over the center 4' of the ceiling so there wouldn't be much curvature to deal with. I'm thinking I would initially put it up with steel bolts and let it rest for some time before replacing the steel bolts with the nylon bolts one by one.
__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Old 10-06-2019, 11:15 PM   #4
Bus Geek
 
Join Date: Sep 2015
Posts: 3,856
Year: 2002
Coachwork: Thomas Built Bus
Chassis: Freightliner FS65
Engine: Caterpillar 3126E Diesel
Rated Cap: 71 Passenger- 30,000 lbs.
Worth an experiment. I would also be concerned with the amount of sag in the middle. That is some thin sheets of plastic afterall. Heat may also play an important role in the deformation of the sheets.
Native is offline   Reply With Quote
Old 10-07-2019, 12:17 AM   #5
Bus Geek
 
Join Date: Sep 2018
Posts: 2,831
Year: 2007
Coachwork: Thomas Built
Chassis: Minotour
Engine: Chevy Express 3500 6.6l
HDPE has a moderate thermal conductivity. Double that of pine. Easy to clean I suppose.
Danjo is offline   Reply With Quote
Old 10-07-2019, 12:50 AM   #6
Bus Crazy
 
bus-bro's Avatar
 
Join Date: May 2007
Location: Whidbey Island, WA.
Posts: 1,109
Year: 1984
Coachwork: Blue Bird
Chassis: All American
Engine: 3208 na boat anchor
Rated Cap: 2
I'd use FRP, i.e. fiberglass reinforced plastic. Stuff like Filon. It comes ten foot wide and is used for everything, such as RV's, semi-trailers, etc.
bus-bro is offline   Reply With Quote
Old 10-07-2019, 01:50 AM   #7
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 6,995
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
Quote:
Originally Posted by bus-bro View Post
I'd use FRP, i.e. fiberglass reinforced plastic. Stuff like Filon. It comes ten foot wide and is used for everything, such as RV's, semi-trailers, etc.
Seems pretty pricey. McMaster-Carr has 4'x8' sheets of 1/8" FRP for $212 each (vs. $30-something for 1/16" LDPE).
__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Old 10-07-2019, 01:53 AM   #8
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 6,995
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
Quote:
Originally Posted by Danjo View Post
HDPE has a moderate thermal conductivity. Double that of pine. Easy to clean I suppose.
Interesting, didn't know that about these plastics. HDPE has a value of 0.48 but apparently LDPE (which I think I'm going with instead because it's cheaper and more flexible than HDPE) has a value of 0.33.
__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Old 10-07-2019, 05:25 AM   #9
Bus Nut
 
farok's Avatar
 
Join Date: Jan 2019
Posts: 375
Year: 2003
Chassis: Chevy cut-away 6-window shortie
Engine: 6.0L Gasser
Quote:
Originally Posted by musigenesis View Post
Seems pretty pricey. McMaster-Carr has 4'x8' sheets of 1/8" FRP for $212 each (vs. $30-something for 1/16" LDPE).
Check out your local big box store... $32 at Lowes.
https://www.lowes.com/pd/48-in-x-8-f...nel/1000174771

This is what I plan to use to cover my shower stall walls, whenever I get to that phase of the build.

Chris
__________________
My build thread: https://www.skoolie.net/forums/f27/fi...ild-25804.html
farok is offline   Reply With Quote
Old 10-07-2019, 08:23 AM   #10
Bus Nut
 
bigskypc50's Avatar
 
Join Date: Dec 2016
Location: MONTANA
Posts: 471
Year: 1995
Coachwork: AMTRAM
Chassis: INT
Engine: DT466
Rated Cap: Big Girl
following this, seems like a good ideal for someone who like my self might have to retrofit insulation over the celling at some point.
bigskypc50 is offline   Reply With Quote
Old 10-07-2019, 08:45 AM   #11
Bus Geek
 
brokedown's Avatar
 
Join Date: Dec 2016
Location: Weeki Wachee, FL
Posts: 3,056
Year: 1997
Coachwork: Bluebird
Chassis: TC2000 FE
Engine: Cummins 5.9
Rated Cap: 72
I'd sure like to avoid doing 3 inch wide t&g planks on this new bus.. So please keep us updated on this project!
__________________
Keep up with us and our build!
Follow us on Facebook, Instagram, YouTube, and Twitter
brokedown is offline   Reply With Quote
Old 10-07-2019, 02:32 PM   #12
Bus Crazy
 
bus-bro's Avatar
 
Join Date: May 2007
Location: Whidbey Island, WA.
Posts: 1,109
Year: 1984
Coachwork: Blue Bird
Chassis: All American
Engine: 3208 na boat anchor
Rated Cap: 2
The FRP I was talking about is this: https://www.recpro.com/rv-fiberglass...V%20Fiberglass
bus-bro is offline   Reply With Quote
Old 10-07-2019, 07:05 PM   #13
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Grayson County, VA
Posts: 1,428
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Quote:
Originally Posted by bigskypc50 View Post
following this, seems like a good ideal for someone who like my self might have to retrofit insulation over the celling at some point.

It can be done with 5mm plywood underlayment as well. We cut it into 23"-ish x 7.5'-ish panels and put a 3" wide trim piece over the seam at each rib. We insulated over the perforated metal ceiling then covered it with the plywood underlayment.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is offline   Reply With Quote
Old 10-08-2019, 11:46 AM   #14
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 6,995
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
Quote:
Originally Posted by Drew Bru View Post
It can be done with 5mm plywood underlayment as well. We cut it into 23"-ish x 7.5'-ish panels and put a 3" wide trim piece over the seam at each rib. We insulated over the perforated metal ceiling then covered it with the plywood underlayment.
I think I'm going to end up using this thin plywood instead of LDPE. I just got my sample bits in the mail and the 1/16 plastic is indeed very floppy and semi-translucent (and prone to scuffing). I'd probably have to put some kind of sticky paper on one side of this to keep the insulation from being visible through it. And the 5mm plywood isn't all that much thicker than the plastic that it would really matter.

The nylon bolts are pretty cool, though, and I'll still use those.
__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Old 10-09-2019, 04:45 PM   #15
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 6,995
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
The 1/16" LDPE sheet is laughably unsuited for use as the ceiling:

Click image for larger version

Name:	LDPE.png
Views:	15
Size:	397.5 KB
ID:	38365

other than the fact that it's super-light. The 1/16" HDPE is stiffer and more opaque but would still sag some over the 26" span between ribs. I have some 5mm plywood and some 2" XPS board now that I'm going to do a test with.
__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Old 10-09-2019, 05:27 PM   #16
Bus Geek
 
Join Date: Sep 2018
Posts: 2,831
Year: 2007
Coachwork: Thomas Built
Chassis: Minotour
Engine: Chevy Express 3500 6.6l
Dexter would like it.
Danjo is offline   Reply With Quote
Old 10-10-2019, 02:26 AM   #17
Bus Geek
 
Join Date: Sep 2015
Posts: 3,856
Year: 2002
Coachwork: Thomas Built Bus
Chassis: Freightliner FS65
Engine: Caterpillar 3126E Diesel
Rated Cap: 71 Passenger- 30,000 lbs.
Borderline transparent!
Native is offline   Reply With Quote
Old 10-10-2019, 09:18 AM   #18
Almost There
 
Join Date: Jan 2015
Posts: 80
I used ply then veneers to make it look good. Use a quality contact cement for the veneers.
Mudhutwarrior is offline   Reply With Quote
Old 10-10-2019, 02:30 PM   #19
Mini-Skoolie
 
Join Date: Sep 2019
Location: Coeur d'Alene, Idaho
Posts: 20
Year: 1978
Coachwork: Thomas
Engine: Cummins V555
Rated Cap: ??
do most of ya'll change the ceiling? is there a forum post about pros and cons of changing from standard ceiling to wood or other material? I believe most of them have some level of insulation behind the metal roofing panels, right?
Wallace87 is offline   Reply With Quote
Old 10-10-2019, 03:08 PM   #20
Bus Geek
 
musigenesis's Avatar
 
Join Date: Jan 2019
Location: Philadelphia
Posts: 6,995
Year: 2003
Coachwork: International
Chassis: CE 300
Engine: DT466e
Rated Cap: 65C-43A
Quote:
Originally Posted by Wallace87 View Post
do most of ya'll change the ceiling? is there a forum post about pros and cons of changing from standard ceiling to wood or other material? I believe most of them have some level of insulation behind the metal roofing panels, right?
The factory insulation is near-worthless. The metal ceiling panels are connected to the metal ribs and outer skin, so because of the thermal conductivity of metal the ceiling will always be close to the outside temperature regardless of what insulation is there between the ceiling and roof (it's possible that the factory insulation is mainly there because of its sound-deadening properties rather than its thermal ones).

Removing the ceiling allows you to add thicker insulation, but more importantly it allows you to put on a new ceiling which has a thermal break between it and the outer bus skin (this post in fact was mainly about ways to achieve that thermal break).
__________________
Rusty 87 build thread
musigenesis is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 07:29 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.