Condensation: Embracing it and showing it the exit vs nesting in a plugged drip pan

[wrenchtech]

Originally Posted by EastCoastCB

Rub rails.

Yes, that is what the screw penetrations that are seen in the picture are from.

The original poster says that he’s going to use a half inch layer of insulating board on his floor. I am going to use 2 inches. Residential building codes for my area call for R-30 in a floor structure that is exposed to the exterior. 2 inches of foam board will get me to R-11. It would take 5 inches of foam board to get to R-30. I am not going to be able to do that for a number of reasons.

[DIYLoFi]

Originally Posted by gs1949

It doesn't sound like that will be a big problem with your capillary system, but I do see what may be something of an issue. I'm not sure how much it will matter, but I think that once your cords become wet, they will hold moisture indefinitely and basically never dry out.

Than you again for the input! My thinking is that if they never dry out, that means it's because the joist-grooves in the metal floor never fully dry out, so I think that the wick system will not exacerbate a problem but will at least slightly address it (the wick will theoretically keep it from pooling.

As for the other ideas about using 'ice shield' roof underlayment on the metal bed, I share the worries about using exterior/attic-oriented products in a living/breathing space in terms of offgas (it is GREAT for low pitch residential roofs under the shingles, though, in my experience!). I also think the Rustoleum industrial rust inhibitor applied liberally after grinding rust will protect the steel as reasonably well as anything from the expected constant dampness. I'd be worried that the ice shield glued down would prevent/prohibit the weeping/wicking that is needed/designed to keep the hydrostatic level from reaching the underside of the plywood.

Finally, I did upgrade from 1/2" Rigid insulation to adding another 1/2" of styro/foil under that (except the cutouts for my PEX radiant heat tubes will be missing the Rigid but also have strips of the foil-bubble-wrap insulation under the tubes).

Great discussion, and even the tangents were interesting and informative. Thanks y'all.

[banman]

Originally Posted by wrenchtech

Yes, that is what the screw penetrations that are seen in the picture are from.

The original poster says that he’s going to use a half inch layer of insulating board on his floor. I am going to use 2 inches. Residential building codes for my area call for R-30 in a floor structure that is exposed to the exterior. 2 inches of foam board will get me to R-11. It would take 5 inches of foam board to get to R-30. I am not going to be able to do that for a number of reasons.

If you're going to be parked through the winter in WI I would highly recommend some skirting to limit the air-flow under the bus.

[banman]

Originally Posted by DIYLoFi

Than you again for the input! My thinking is that if they never dry out, that means it's because the joist-grooves in the metal floor never fully dry out, so I think that the wick system will not exacerbate a problem but will at least slightly address it (the wick will theoretically keep it from pooling.

As for the other ideas about using 'ice shield' roof underlayment on the metal bed, I share the worries about using exterior/attic-oriented products in a living/breathing space in terms of offgas (it is GREAT for low pitch residential roofs under the shingles, though, in my experience!). I also think the Rustoleum industrial rust inhibitor applied liberally after grinding rust will protect the steel as reasonably well as anything from the expected constant dampness. I'd be worried that the ice shield glued down would prevent/prohibit the weeping/wicking that is needed/designed to keep the hydrostatic level from reaching the underside of the plywood.

Finally, I did upgrade from 1/2" Rigid insulation to adding another 1/2" of styro/foil under that (except the cutouts for my PEX radiant heat tubes will be missing the Rigid but also have strips of the foil-bubble-wrap insulation under the tubes).

Great discussion, and even the tangents were interesting and informative. Thanks y'all.

I also think the para-cord will tend to stay damp longer than leaving a free space...

Several thin coats of paint are more effective than a thick coat.

I would paint the bottom of the plywood (side touching metal) with an oil based paint before installing it to prevent the creep of moisture into the wood.

[gs1949]

@DIYLoFi, I don't think the seams between my floor plates have ever seeped or will seep in the future. While rereading this thread just now I reread the post I made earlier in this thread about what I am doing with my floor, and I can see that I left out the Dynatron 570, which is the white verson of 550.

After I removed the rotten plywood, I saw that all the seams between floor plates were sealed with seam sealer. The way the plates meet leaves a little groove there, and it was full of seam sealer. I removed all the old seam sealer before I started the ospho and rustoleum process. Then, before the last top coat of rustoleum enamel, I filled that little groove with a bead of my own dynatron. Then I waited a couple of days for the dynatron to harden a bit before putting the last coat of enamel on top of it.

@banman, I painted all sides of my 2X4s and the bottom side of my plywood with zinzer 1,2,3 primer followed by a coat of water-based barn paint. I intend to paint the edges of the plywood after I cut the panels to size. I did this because when I removed the old plywood I noticed that some sheets of plywood had been painted on the downside and some had not. The difference in the amount of rot I found on the painted sheets as compared to the unpainted sheets was quite striking, so I decided to paint all the wood for my floor.

[banman]

Originally Posted by gs1949

SNIP...

@banman, I painted all sides of my 2X4s and the bottom side of my plywood with zinzer 1,2,3 primer followed by a coat of water-based barn paint. I intend to paint the edges of the plywood after I cut the panels to size. I did this because when I removed the old plywood I noticed that some sheets of plywood had been painted on the downside and some had not. The difference in the amount of rot I found on the painted sheets as compared to the unpainted sheets was quite striking, so I decided to paint all the wood for my floor.

Sounds good.
I can only hope my plywood was painted 18 years ago...
I haven't felt any soft spots in it yet...

[gs1949]

My plywood was a lot worse of than soft in places. It rains quite a bit in Auburn WA.

[gs1949]

Originally Posted by EastCoastCB

Rub rails.

Now that I've had time and daylight enough to check, I see that my memory was correct and I have no screws there. My rub rails are held on by rivets. I think those may be what are called blind rivets. They appear to be one, solid piece of metal. There are no seepage trails coming from rivets in the several areas of the bus that I looked at today. I looked at maybe a third of the wall panels and saw no seepage trails coming from any rivets.

However, there are some seepage trails running in that area, but that seepage ran from above, i.e. from the windows, and then ran between the rows of rivets on the way down. Of course, I already knew about the leaks from the windows and I am dealing with that issue as I go.

[Native]

Originally Posted by gs1949

I did this because when I removed the old plywood I noticed that some sheets of plywood had been painted on the downside and some had not. The difference in the amount of rot I found on the painted sheets as compared to the unpainted sheets was quite striking, so I decided to paint all the wood for my floor.

I painted all of the furring strips and the underside of the plywood subfloor in our installation.

[musigenesis]

Originally Posted by Native

I painted all of the furring strips and the underside of the plywood subfloor in our installation.

I want to do this with all the wood I put into my bus, but I'm unable to paint anything in the cold, and pre-painting stuff (like the metal going into my floor replacement) just slows everything down for me so massively.

[gs1949]

Yeah, I guess they are furring strips. I've just been thinking of them as 2X4s.

I worked with lumber a lot during my married with children phase,. I routinely looked at thousands of pieces of lumber every day and made a decision about every one of them. I guess I'm still burnt out from that.

[Native]

Originally Posted by musigenesis

I want to do this with all the wood I put into my bus, but I'm unable to paint anything in the cold, and pre-painting stuff (like the metal going into my floor replacement) just slows everything down for me so massively.

If it ain't the cold, it's the rain!

[Native]

Originally Posted by gs1949

Yeah, I guess they are furring strips. I've just been thinking of them as 2X4s.

I worked with lumber a lot during my married with children phase,. I routinely looked at thousands of pieces of lumber every day and made a decision about every one of them. I guess I'm still burnt out from that.

Lumber selection is a tedious process at times!

[gs1949]

When you're doing it at over 70 pieces a minte, it's not really tedious, I think after doing it for years anyway..

[Native]

Wow ... 70 per minute ... mind numbing.

[gs1949]

Yeah, pretty much.

[Doktari]

It would be nice to insulate the outside of the floor pan (under the bus). Then lay electric floor heat on top of the floor pan. This would evaporate any moisture or spills that gets down into the floor. Also insulating under the floor does not take away headroom.

[kidharris]

Originally Posted by musigenesis

I want to do this with all the wood I put into my bus, but I'm unable to paint anything in the cold, and pre-painting stuff (like the metal going into my floor replacement) just slows everything down for me so massively.

Maybe use an oil based stain, preservative, or coat it with linseed oil like the old timers did. I don't think that cold would be a problem for these possible solutions.