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Jay. As you can see there is a wealth of information. Too many choices really.
It's like a painting. At what point do you stop grabbing more information and just paint?
I like your steel plan and I see why you are going that route.
I know nothing about it, and my only question is will 3/4 steel tubing hold the curve you want, or over time will it tend to flatten back out?
As far as insulation goes if I had a bigger budget I would just use wool for everything.
It's clean, simple, natural and has great R value.
Thinsulate is great and easy to work with, but a bit expensive as well, and harder to get here in Canada.

So I did my research and I am going with rock wool everywhere.
Rick

 

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Those are some good considerations to bring up about installing it in place, thanks! I've never seen a fiberglass fire and I hadn't thought of the heat of welding the plates in place and the potential issues with the fiberglass.. Maybe I do need to construct them outside the rig and then bring them in and install.

I think the beam should be able to hold the curve no problem; with it being sandwiched between the sidewalls, welded to the face plate and fiberglassing it all to the sides and ceiling I think everything will get locked into place and be super solid once cured. At least that's my hope.

If anyone has any thoughts or suggestions about this  I'd love to hear, again I'm just shooting from the hip on this stuff.

I've been looking at Thinsulate for the roof and upper side walls where that step is, but for the side walls I think i'm just going to use rigid foam insulation. Can you compress rock wool down much? Looking at it seems like a great option but at least in the roof I'm only going to have 3/4" space for insulation, not sure that's an option for my ceiling.

Edited by JaySam

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If you fiberglass the steel tube to the ceiling while you've got it forced into a curve as you picture, the tube will forever be trying to pull down and straighten itself. The fiberglass might or might not be able to maintain the curve, without failing but it kind of defeats the purpose of the tube. I would suggest you try to put a curve in the tube before glassing it in.

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I you will find that most of the R-value of rock wool is in the dead air space that is trapped inside when uncompressed.  If you compress it down to 3/4" I don't see much insulating value.  Probably better off with some sort of foam.  

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Thanks for the advice Derek, that's kind of what I was wondering and just didn't know. I thought that with the end plates holding it in place it would 'spring' the steel upwards and therefore help maintain the curve and the weight. I'll attempt at putting in a moderate curve, weld face plates on outside the rig and then slide it up into place and see where that gets me.

I figured batting just wasn't going to work for me but was hoping someone had a suggestion for something, that R-15 value sure is attractive compared to foam board.

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Actually I am not compressing the rock wool. I'm just cutting it down to whatever depth I need.
Certainly I am not going to get its rated R value, but even cut in half or quartered it is pretty good. And it's easy to work with. Cuts easy with a bread knife and holds its shape even when installed in a vehicle.
The reason I didn't go with rigidd foam is that the right kind is hard to find here. And again, it's lack of availability makes it $$$.
Rick

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1 hour ago, JaySam said:

I thought that with the end plates holding it in place it would 'spring' the steel upwards and therefore help maintain the curve and the weight.

 

You don't get nuthin' for nuthin'! :) That's going to put a tremendous outward force trying to spring your walls apart. I don't think I'd want to go there!

 

You want R-15? Better design wall/ceiling of~3"+ thick.

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Haha good point! I started thinking about the outward pressure the more I gave it thought and realized that might not be good in the long run either. Your right that the steel wants to flatten out once the middle brace is removed, I'm now going to bend the curve into the beam outside the truck, weld the end plates on and hopefully I have the skills to build it all for a match fit. I do think glassing into the ceiling will help hold the curve some but adding the proper bend into the beam will be best like you stated. Thanks for the advice on this aspect of the build Derek.

 

I want R-15 but I know i'm not going to get it lol. It's a game of inches and I guess it  just depends on which inch you want to give where...

 

Rick: good idea on cutting down to width, I hadn't thought of that. Still a few weeks away at least from needing to make those decisions so I have some time to continue to think it over.

 

One day I might actually use this damn thing.

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Jay. Yes, eventually we will get it out of the driveway.
I think after Derek's sage advice I will go back to my original plan of a rectangular aluminum beam that is pre curved at the shop.

I don't have to fiberglass mine in, as the two beams I am putting in are merely supplemental to the wood structure I already built.
I just want the added strength and will just need two.
As for plates etc, I will get around welding aluminum by creatively using 3M5200, then bolts through the plate to outside.
And, if you have any interest, time, money, the Rockwool folks also make a couple of very cool products that come 1" deep on a roll, similar to Thinsulate.
Check its website.
I just went for the best bang for my buck and got the regular 22R bail and am cutting and fitting as needed.
I understand what Derek is saying, but I have no interest in having 3" + walls.
I don't mind wearing a sweater when it's cold, and less clothing when it's hot.
I don't need my RV to have all the cozy comforts....

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Take a plate of 1/4" aluminum 4"x4" cut a 1"x1" notch in the in the middle of the top, "U shaped". Cut the cross beam to the EXACT length needed. Install the cross beamput glue in the notch and slide the plates up into place. Bolt the plates in. The walls of the notch will take the shear forces.

I suppose you could even use 1/2" plywood for the U bracket.

 

 

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Rick: I browsed around on Rock Wools site but didn't find anything in the 1" range, do you think you can add a link for me?

 

Are the wood beams you installed just not holding up enough and that's why your adding aluminium? How are they going to work with your existing ceiling?

 

 

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Oh gotcha thanks Derek. I thought maybe there was a rock wool batt type insulation in 1" that I couldn't find.

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Jay.
This is what I was looking at... but there are lots of different types on the site.

https://rti.rockwool.com/products/industrial/prorox-wm-950-es/?selectedCat=industrial - all africa
As well, if you dig deeper into the Rockwool website you can find thinner insulation designed to be used with fabric etc. Similar to Thinsulate.
The wood beams and grid that I built on my ceiling is fine, but I would like a little more curve overall.
My situation is unique in that the roof suffered extensive damage from a large tree limb. It tore large holes in the roof and although I got it after someone had done some epoxy repairs it was in rough shape. I have it now to a point where I believe it is structurally sound and nearly water tight, it is a work in progress.
Also, as Linda was pointing out, structurally it just makes sense when you have everything exposed to put at least a couple of metal beams in.

 

And as for what WME is saying here:

"Take a plate of 1/4" aluminum 4"x4" cut a 1"x1" notch in the in the middle of the top, "U shaped". Cut the cross beam to the EXACT length needed. Install the cross beamput glue in the notch and slide the plates up into place. Bolt the plates in. The walls of the notch will take the shear forces.

I suppose you could even use 1/2" plywood for the U bracket."

 

If you cut the cross beams to be "the EXACT" length needed, how to you get the curve?
Is WME suggesting that your idea of straight steel tubing will work using his method?

 

The measured curve is about 3/4" at the middle. So in the big scheme it isn't that much.
But as you have pointed out, every 1/2" counts...

 

Rick

Edited by canadasunrader

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I would only use a straight tube if I was trying to have a flat roof. And even that won't be flat once you install a roof A/C. :)

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"No matter how many times I cut it, its still to short😁"

Start with tubing that to long add the bend and cut to fit

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Ok well here's where I'm at so far. I took 72" x 3/4" steel tube beams, marked them off and began to give them some bend using a fencepost and my garage wall. Once it had enough of a curve to it the beam would just barely fit up into the roof area. I held it in place and used a 1/8" steel plate to extrapolate the angle of the sidewall onto the beam. Then I cut the ends off at that line and moved the beam further up into the ceiling. I marked it again, cut off at the line and it ended up being just about the perfect length side to side once I propped it up into place with some 2x2's. I then used this beam as a template to build the next one. Being propped up on each end the steel beam holds the roof up pretty well and seems plenty strong.

 

The curve I added to the beams is much greater than the actual curve of the roof. The deflection of the beams is a good couple of inches. But once wedged into place on either end it holds the roof up nicely and has a pretty decent curve. I contemplated pulling the roof curve, building a jig and bending the beams with clamps and jacks, then I said oooo it and just started bending between my garage and fence. This approach actually seemed to work quite well as different areas of my roof sag more or less than other areas and seem to have more resistance to being propped up in different places as well. So I would prop the beam up, look at the curve from inside and out, and then bend a little here and there until I felt like the curve was pretty uniform and even, although the bend in the beam was not.

 

It seems like now I can either trim the ends, weld a metal faceplate and glass that on or build a header beam that runs underneath all three rafters with U pockets and fiberglass that to the wall. I'm leaning towards a 1" thick header beam that runs the length of the cabin so I have something to tie into later if I need it for cabinetry or anything else. Also if I do a wooden header beam I think I can leave the rafters in place once I find my final resting spots for them and build the header into place around them, ensuring I maintain the curve and sweep I want in the roof. Then I'll fiberglass everything to the shell and roof and call it good. 

 

With the beams propped into place I can now stand up wearing thick soled shoes underneath a rafter and my hair just barely grazes the rafter. Granted I have a shaved head but that means for now I can fully stand up. Of course once I add a floor in I'll only be able to stand up fully in flip flops or bare feet, but it seems like all the work will pay off and I'll be sitting (standing) pretty.

 

Thanks to everyone's suggestions and advice so far, it seems like I'm going to use a little bit of everything to end up with a final product so I appreciate all the help.

 

 

RoofCrop.jpg

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Bravo Jay.
Looks good so far.
Rick

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Thanks Rick, it seems to be coming along pretty well and working out roughly how I imagined it. Now to begin learning the fiberglass process and waiting for some warm enough weather to get it done. I still need  to fashion 1 more beam for the cabover area as well but all in good time.

 

How are you going to add the aluminium beams to your current ceiling? Are they going to sit underneath the wood frame you built for support or be integrated into it somehow?

 

Additionally how many vertical beams are you adding into your side walls for support? You're glassing in double wide steel beams for the vertical supports correct? How has that worked out?

 

Have you begun to mess with or install the rock wool at all? I really like the looks of the product and the insanely high R value along with sound deadening properties is really attractive. Any thoughts on how much R value you lose by cutting the width lets say in half? Do you lose half the value?

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1 hour ago, JaySam said:

Have you begun to mess with or install the rock wool at all? I really like the looks of the product and the insanely high R value along with sound deadening properties is really attractive. Any thoughts on how much R value you lose by cutting the width lets say in half? Do you lose half the value?

 

R-values are express in R-value/inch of thickness. Often, much of the value is due to air trapped in the insulation. Roxul/Rock Wool isn't 'insanely' different from fiberglass batts. I believe Rock Wool R15 batts are 3" thick, so R5/inch.

 

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image.png.9e095882d13bf3ffb349290644a532a9.png

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Compared to rigid foam, the best type that I can't even find here, the rockwool, at R22, and $50cdn a bail is going to be just fine. Some of it will be cut down to 1" thick, but around the wheel wells etc it will be great thicker.
Is it perfect, of course not. But it's going to be fine, and it's what I can afford.
Rick

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Looks like my best option for the ceiling is rigid foam board, it gets a R 4 value which is actually a little higher than even the 3m Thinsulate. Advantage of thinsulate is the acoustic properties as well, so I may go with that in the ceiling and do foam board on the sides where I can go a little thicker.

 

Rick, are you going to put in any sound deadening material in the cab or the coach area? I'm thinking of adding some maybe on the wheel wells and in select spots but am not sure as I've never used those kind of products before. Of course I'll line the cab with it but am wondering about the coach area, what are your thoughts there?

 

Since my insulation requirements are rather thin I think I'll also opt for a little bit bigger heater than I need to make sure to keep it toasty.

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Derek.
There is a big difference between regular fiberglass batts and rockwool.

Fiberglass is not recommended for anything moving unless it is completely sealed up, and even then it has a tendancy over time to break apart.
The rockwool is easy to cut as it is stiff. You can easily cut it with a bread knife into any dimensions you like.
As said, it's not my first choice, but it will work.

Jay.
Like you, I don't know much, that's why I'm here.
Learning a lot.
Yes, I plan to insulate the wheel wells etc. Not there yet, but that seems like a pretty easy job compared to everything else.
Just finished the second front plexi window now.
They are not easy.
And I tested the first one and it is leaking a bit. I am assuming it is because it is curved.
I heated the plexi up and put some patio stone on top to try and straighten them. The second one seems a bit straighter than the first.
I plan to use some polyurethane caulking around the top and on the inside of the bottom of both these windows just to make sure before I close up the cabover bed area.
Rick

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Hey Rick, good to know about the rock wool. Still might use that as an option since it's readily available, decently priced and seems to have similar properties to something like thinsualte. Anyway like I said I still have some work to do before I get there.

Have you considered a sound deadening material for the coach at all? Something like rattle trap or noico? Wondering if those are worth the time and money or if just stuffing insulation over the wheel wells is enough

How hard were the front plexi windows to do? Mine seem to be holding up fine but I'm wondering if it's worth the effort to pull and replace the gasket and seal for peace of mind or if it's not worth the trouble if they aren't currently leaking...

 

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Pick up bed liner on wheel wells and around the seams. You wouldn't believe how much dust leaks in where the plastic wheel wells mate against the wood floor. 2 coats, waterproofing and sound reduction. Best thing is it sorta cheap

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Jay.
I have not looked into sound deadening materials.
Someone here on the forum should be able to answer that, or just google and one of those van life folks will definitely have a blog or youtube post about it.
I am planning to put a thin layer of cork underlay on my floor before I put a final something on top as a floor. And I know that the cork will provide some help with sound.
And then I plan to put a pretty good layer of the Rockwool onto the wheel wells before I put cabinets in.
I am hoping that will be enough. Who knows?
Windows.
If they are not currently leaking then I wouldn't touch them.
Simply clean them up and move on.

Mine were leaking and I had to deal with them while I still have everything exposed.
Rick

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WME: Are you thinking something like herculiner ? Or do you have a suggestion for a product?

 

Rick: Good to know, I think i'll leave the windows as is and be thankful there's actually one thing i don't need to fix or rebuild on this thing.

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Hey Jay.
How goes the battle?
Did you glass your ceiling beams in?
How is it all shaping up?

Rick

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On 2/20/2020 at 9:26 AM, JaySam said:

WME: Are you thinking something like herculiner ? Or do you have a suggestion for a product?

Yes, Rustoleum has a bed liner kit you can get at Walmart. Its barely OK for a pickup bed. BUT you are going to use it in a protected area. You just want the sound reduction and weather sealing.

For use in the cab check out Dyna Mat and its clones. Low budget plan B is this stuff...https://www.menards.com/main/building-materials/decking-deck-products/deck-flashing-supports/12-x-25-deck-flashing-tape/dfb1225/p-1462879491609-c-5728.htm 

If $$ is a problem then a can of flex seal just for the wheel wells

Edited by WME

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Jay. I followed your lead and installed 3/4" steel beams.
I bent three of them into a curve and after notching the headers, I glued and screwed the beams onto the wood structure I built to replace the rotten ceiling.
As you said, the steel seems to hold the curve well.... so far.

IMG_3421.jpg

IMG_3425.jpg

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Hey Rick,

Unfortunately I have not gotten to glassing the beams in yet, I haven't even built the header beam for the sides yet. I'm hoping to build the headers and beams for the coach as well as the bed area this weekend, if I can accomplish that I think I'll actually be ready for glass the following weekend. If the temps are good enough. I still need to decide if I want to glass over the vents or if I'll reuse them for appliances down the road. When you glassed in your vent what kind of backing material did you use? 

 

It's been slow going for me the past few weeks, a little frustrating but just gotta keep fighting. 

 

That's looking really good! I was wondering how you were going to add those beams in. The pics from your other thread look great too, your really making your way along and getting some progress done. How are you going to construct your walls? Are you going to use rigid foam or are you still looking to use wool throughout? 

 

How did you go about bending the beams? My method produced a bit of a rough result, I'd like to try to smooth the curve out a touch but am debating on how much it'll really change and if it's worth all the extra work. At this point I'm feeling like i just need to get things done and move on with the build, there's still a long ways to go.

 

Everything still the same as it was a few weeks ago... 

 

 

20200223_161051.jpg

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Jay.
I bent the beams in the garden. Ha!
I have some solid raised beds and I used your advice and went slow bending a little at a time here and there until I had a reasonable shape.
This is not a perfect science. And I am such a poser, it hurts. But I am having fun and doing my best.
I wouldn't worry too much about perfecting those beams now that you have them in. I would think function is paramount.
As well, once you get your ceiling cover in, the beams, exposed or not, will seem light years away with everything else you are doing.
I am not going to glass mine in. I used a few screws into the wood, and a good amount of Sika polyurethane adhesive. I want to make sure the beams are attached and doing their job without being too rigid. The poly is great for RV work because it is a great glue but becomes rubber and flexible. I don't like the curing time of 5 - 7 days, but it all takes time.
I now have a bunch of 2x2s holding it all up a little higher than it will finally settle to, and I always hold my breath when those are finally removed.
As for the insulation, I am just finishing up my four vertical steel beams. They are glassed in, but I also added some rubber bumpers into the space behind them.
Again, I'm just making this up as I go. Instead of just filling the space behind with spray foam, I first put in a few small pieces of plywood using polyurethane to glue it to the shell and to the steel beam. The poly cures nicely into a rubber-like fill that will allow some movement.
I am planning to use the wool. I cut it down to one inch sheets with a bread knife and used 3M spray glue to hold it to the shell.
I am waiting until I pull some wire before I can even think about getting the wall and ceiling panels going.

Voids? Fiberglass. I just followed what has been advised here and on the web. For my initial cover I did not use epoxy because it is expensive. Instead, I used resin, and it's about a 1/4 of the cost.
It's good, and fine, but a little trickier to work with than epoxy. It is very toxic to work with and you have to wear all the protective gear, masks etc.
I screwed thin plywood pieces onto the outside of all the voids.

You take packing tape and stick it to one side of the plywood before screwing it on. Resin does not stick to the tape making it easy to remove the ply once you have the insides done.

On the inside you need to grind off the screws so you have a flat, clean space.
Then use sheets of fiberglass gradually larger matt and build up layers until you have five or six layers ending with one sheet of matt that covers the hole and about three inches all around.
Those Bound for Nowhere folks have some pretty good pictures, video and info on how they did it.

 

I am still working on the outside of the voids. It takes a lot of patience to sand and fair all of this.
I am not sure what vents I will need in the end, so I am just covering up everything.
I am not going with propane so I don't need a big hole for that.
I am not sure what fridge I will get and if I even need a vent for that.
I always cook outside, so no stove vent.
Who knows where this will all end up, but for now I will just get the outside as good as I can, with plans to paint.


Rick

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