Mothra Metamorphosis

[GrantRobertson]

Have you sourced some scaffolding to work on the roof?

Don't need any.

 

[GrantRobertson]

First thing, buy a larger than you think you need... tarp.
photo 2 is a reminder to put in wiring.
photo 3 is a rubber roof install.

I will be replacing members one at a time -- from the inside. The existing sheets of plywood will remain in place until all the joists are in place. Then I can cut all the sheets of plywood and pretreat them before putting them up. Then I can strip off all the old plywood and replace it in one day. If I tape the seams it will remain relatively waterproof for a while, without anything else on top.

Next, I'll stick on the drop edge.

Then I can glue some foam insulation on top in a couple of hours. Shaping it into a slight curve will be the most time-consuming (and messiest) single operation.

Then I can waterproof some sheets of thin floor laminate, cut them to shape, and glue them on top of the foam, held down with some weights for a day.

Then I can roll out the EDPM, or whatever, glueing it as I go, one or two feet at a time. This will take about a day.

Then another day for tediously adhering the EDPM to the drop edge and folding it under.

Then I will be under a dry roof and will have all the time I need to run wiring and put the insulation between the joists.

 

[BradKW]

Hey Matlock, nice job!

 

[Patrick46]

You say that the framework is rusty??

How rusty?? Is it surface rust, or can you punch right through it with your hand or a skrewdriver??

Surface rust is NO PROBLEM, and does not need to be removed!

Scuff it down with a Scotchbrite pad, paint some Ospho on it, clean it, and repaint it with Rustoleum.

I'm encouraged that this has a steel frame!



I see you aggressively dismantling this camper in the name of rebuilding it into something better and stronger...but I also hear questions that make me wonder if you've ever done this sort of undertaking. True??

I just don't wanna see your project get away from you, to the point that your ambitions undermine your own dreams! (Sadly, I've seen it before.)

 

[GotSmart]

When running wires, NUMBER EVERY WIRE with a sharpie as you run it. Give yourself extra, just in case!   :blush:

 

[rvpopeye]

I think you're overthinking and creating a lot of extra work and expense for yourself....whaaaaaat , whhhhyyyyy ?

On a 8 foot wide rig , a 1/2"/foot taper is only 2" @ 4' from center to each edge. Skip the side vents , they'll leak whenever you're moving or the wind is blowing.

A roof w/2x4's 16 o/c (perfect for your 14"x14" vent cutouts)and 1/2"or 3/4" plywood (osb might be asking for future problems , although they do have some with a waterproof coating now for walls and roofs) + sealed well with something that ends up white (always cooler), will be way more roof than most have and will make installing roof vents , solar , etc. way easier AND will cut down on weight , cost , time + fabricating nightmares !

The 3" of insulation will keep you plenty warm/cool and bathroom panels (FRP is awesome stuff !) on the interior , will be a vapor barrier and keep moisture form condensing up there and in the walls if you go with that there as well (a plastic sheet if using regular wood).
Don't forget thin is best weight wise....and the insulation will be a vapor barrier also.


If you still want to taper (don't forget , that will add to total length), cut the 2x4 down an inch on each end with a nice , easy to do straight cut and lay the ply on that , giving you 2 flat sections with a 1" peak (plenty for runoff, 1/2" might be enough too) , (you can even rip a little angle on the mating edges of the ply if you're worried about the gap at the peak.....I'd suggest just a little filler...bondo?if your coating won't fill it).. and then make your vent cutouts , do the waterproofing roof coat of your choice (sealing the cutouts as you go too), done on top! Walls won't need anything very thick for panels.... Insulate , inside panels and done,done!

Just my 2c worth (of spinach).

 

[GrantRobertson]

OK, folks. I was an electronics technician for six years, then a network manager for 12. I know my wires. I have been working on houses for decades. I have completely rebuilt a bay window on a house. Not to get huffy, but it seems as if folks are reading way too much into what I wrote, or perhaps aren't reading all of it. Seriously, how much less complicated can some 2x4s with plywood on top, then some foam, then some underlayment, then some EPDM be? This ain't rocket surgery.

The corners will be more than adequately braced.

 

[GrantRobertson]

On a 8 foot wide rig , a 1/2"/foot taper is only 2" @ 4' from center to each edge. Skip the side vents , they'll leak whenever you're moving or the wind is blowing.
...

If you still want to taper (don't forget , that will add to total length), cut the 2x4 down an inch on each end with a nice ,

D'oh, my math was off. Calculating in my head as I typed.

The 2x4s will just be straight. All the slope will come from shaping the top foam. That keeps all the strength of the 2x4, especially where it is needed at the corner, for rigidity. It also allows me to install the 2x4s one at a time UNDERNEATH the existing roof.

The "vents" as you call them will just be little 1/2" holes with a 90 degree elbow fit into them and some screen. But that may or may not happen. Not my priority right now.

 

[SoulRaven]

Smart money would use galvanized metal building studs fastened with stainless steel pop rivets.

 

[highdesertranger]

ok this is what I would do 86 the 2x4's, 2x4's are not rated for roofing runners anyway. the minimum wood for rafters is 2x6. I will look later to see what the span is for 2x6. replace the steel runners with steel runners, use a thicker gauge steel. no wood is going to be as strong as steel. no OSB, use marine plywood. OSB cannot handle moisture, there is no such thing as marine OSB, there is a reason for that. I would forget sloping the roof, there really is no need if you build a good roof and seal it tight. I think you might be over thinking this whole roof thing. imo. highdesertranger

 

[SternWake]

The House recently built nearby used OSB for the roof, about 5/8" thick, and one side is aluminized to face inward for lesser emissivity. I had not seen this before.

I have a scrap I've kept outside in the elements on the ground for over a year, and it has only just begun to swell and only in the areas where the aluminized skin was torn/ripped.

I think the glues and methods they use to make OSB of today has greatly improved over the OSB of yesteryear, that we all can imagine as a wet heavy swollen moldy mildew infested nightmare.

I'd still seal the edges where a saw cuts the newer OSB.

I think Plywood is now just the much lighter, more expensive option.

I'd not use OSB just for the increased weight over plywood, and save money elsewhere.

Cutting plywood is bad enough with the glue adding its own lung searing stink, but OSB is a blade dulling even more toxic cloud.

Shaping the curve of the roof into layered foam panels? As someone who has shaped many foam surfboards with modified power planers which can take much more depth on a single pass, this sounds extremely labor intensive and getting it non warbly, will require a very large sanding block to take down the high spots.

 

[GrantRobertson]

I unloaded the RV at the landfill today. It cost me $101, including the neon best I had to buy for $5. Here is a picture of the pile inside the RV.

And here is a picture of the pile after I threw it out the door:

Ok, I also took some of my son's trash while I was going. But the first picture is all mine.

I then spent the rest of the morning vacuuming out as much dirt as I could.

 

[GrantRobertson]

Oh, I didn't know how well the RV would handle going down into and back out of the landfill, but it did just fine. It was some pretty sloppy mud most of the way and it didn't even act as if it was going to get stuck. The tires are practically off-road tires, so that helped.

 

[GrantRobertson]

I'll price out 1/2" plywood. Maybe even weigh it compared to the OSB. Every piece of wood that I will put in there will have every surface saturated in deck sealer after cutting and sanding but before installing.

Some people may be able to afford to build an entire RV in marine grade plywood. I cannot.

I know shaping the foam on top will not be easy. That is why I said it would be the most time consuming part. It doesn't have to be perfect. I definitely do want to curve it though. I think a peak would look ugly. And I will not settle for a flat roof. I've already seen how much water can pool up there, even on a "flat" roof. With all the solar panels I plan to put up there, there will be a lot of holes for mounting brackets. I don't want any water pooling up around those mounting brackets, no matter how much DiCor I plan to slather all over those brackets.

In fact, even though a 2" rise is enough, I think I will go for a 4" rise anyway. Yes, I know, that's a lot of insulation.

I know 2x6 is standard for floor joists and rafters. However, that is for a span that is much longer than 8'. On the one hand, I got someone telling me to just use 2x2s, and on the other I got someone telling me to use 2x6s. I think good quality, hand picked 2x4s will be just fine.

I'm gonna have to do my own research on using industrial roof covering instead of standard RV solutions. If I can't find anything, then I am fine with just using a standard RV roof covering.

Does anyone have any suggestions on where to order this stuff?

Recommendations of EDPM over other solutions? I will want to glue it down all over instead of just the edges. I do not want a "paint on" only coating, though I know I will need to paint something over the EPDM or whatever, on a regular basis, to protect it from UV damage.

 

[GrantRobertson]

You say that the framework is rusty??

How rusty??

The entire frame for the house is just about a rust heap. The roof beams are completely gone in spots. I haven't torn out the insides of the walls, but from what I have seen, it is really bad too.

Fortunately, everything from the Ford factory is pretty rust free. Just the stuff that Fleetwood put in is rusted and rotted out. Sure would have been nice if they had used aluminum instead.

Yes, I will be completely rebuilding the whole house by the time I am done. But I DO NOT have the luxury of tearing everything off in one go and rebuilding from scratch. I will soon be living in this thing due to no other tolerable options, and so I will need to keep as much roof physically over my head as possible at all times.

Well, time for the old grindstone...

More about the floor, later.

 

[BradKW]

Hey Grant, there might be confusion about what I said earlier regarding need to coat peel and seal to protect from long term UV damage. That is true, but if just making temporary repairs there's no need as we're talking about degrading over 5+ years.

However, Peel and Seal is not EPDM, and EPDM does not require a protective coating...in fact, getting adhesion to EPDM (ethylene propylene diene terpolymer) is tricky. Anyway, something you said above made me want to make sure there wasn't confusion.

That said, EPDM is certainly a commercial grade product, especially the heavier gauge. I think it comes in 40 and 60mils, choice of black or white. Its probably going to be your best bet, especially from the standpoint that you'll be able to source it in the width you want. Other commercial products require specialized equipment to create a monolithic system out of smaller pieces.

On a different topic, the idea of trying to shape foam into a pitched, curved roof is kinda scary. I've had to shape foam on roofs and carve out long drainage gutters into sprayed foam, and what I understand you to be proposing would have me running the other direction. Just the mess, attempt to contain it on a breezy day, and the constant cleanup would be awful. I didn't pay close attention to what you plan for rebuilding structure of roof, but have you considered something as relatively simple as ripping 2x6 in an arch, 1" being height of both ends, and then bending some 1/4" plywood over it? Not simple-simple, but certainly doable and have a nice end product...

 

[SoulRaven]

The only practical way for the OP to recover his investment would be to strip it to the bare chassis, buy a used 7' x whatever the frame rails will fit enclosed trailer mount it to the chassis less tongue, axle, tires and suspension and use it as a toy hauler.

 

[travlinman and wife]

Grant I would do what Bradkw said. You could take them to a cabnet shop or a high school wood shop and ghet them cut. the safe span for different size lumber is2x4 12in oc is 8ft 10in. 16 in oc is 8 ft. 2x6 12 in oc13 ft 7 in. 16 in oc is 11 ft 9 in. 2x8 is 12 in oc 17 ft 2 in. 16 in oc is 14 ft 11in.

 

[Canine]

I would recommend not using 1/2 inch plywood or 2x 6s.Too much weight.I would pre fab the walls using 1/4 inch ply on the outside and 3/16 luan on the inside,glued and screwed to 2x2s 16 in on center.Of course you would want to glue 1 1/2 in insulation inside.I would use 2x4s arced to 2 1/2 inch on the ends.Cover with 3/8 ply.Too bad you are not close by,we could knock that puppy out for you.

 

[Cammalu]

Is there a reason you will use wood over aluminum? I noticed that everyone seems to use wood