Anybody ever just use paint on exterior?

[CLChastain]

Dano, my thoughts are that, generally speaking, a house doesn't move. They may settle a little, they may give microscopically in the wind, they may shake infinitessimally when a big truck goes down the road, but they generally don't get jostled like a trailer going down a potholed road -- trailers being minimally framed and constructed compared to a house. I think, regardless of what's chosen to skin the cabin, longevity will depend on keeping any water from entering microscopic cracks, fastener holes, expansion and contraction due to heat and cold...

Tom, I agree about the roof. Most house roofs aren't even comparable. They have a slope, they have overlapping shingles that are nailed down, bigtime. Other types of house roofs aren't vulnerable like trailer roofs. Tar and gravel on roofs that are flat or have a very shallow slope...Our circa 1957 "Florida" cinderblock house originally had a tar and gravel roof. In the early 90s, just before we bought it, house flippers put on a torch-down roof. It made a very thick membrane under the shingle-like coating that's still good after years in the Florida heat and several pretty; strong hurricanes...

Travel trailer roofs aren't the least comparable, IMO. I don't think a curved TD roof would have a pooling problem, but a flat one like I'm planning might. The roof beams I plan to use (salvaged from the old Aristocrat Lo Liner) are cambered, but not much. I'm planning on using some kind of paint-on rubberized roof coating and putting no holes in the roof. I'm less concerned about the roof than the walls, though. I want whatever exterior wall solution I decide on to be economical, sufficient and nice looking....

[KCStudly]

There is a lot of discussion about this over in the foamie forum. One theory, that I subscribe to, is that bent roof ply is far more susceptible to having splits in the paint coat due to the wood fibers not being strong along the access that we tend to bend our roof ply. Simple paint does nothing to reinforce the wood fibers, whereas canvas fabric has fibers running in both directions. When adhered to the wood the canvas provides a structural tension member to help keep the wood fibers together, and provides a very stable substrate for paint. Taken a step further, it is reasonable to consider that strains from temperature changes and dynamic loading (i.e. jostling down the road) would effect flat ply similarly.

Sure, those garage kept paint only examples look great, but we can't all justify storing our campers indoors. Sure, many houses last years outdoors with painted wood exteriors, but they take a lot more maintenance and don't last as long as vinyl or aluminum siding.

My recent tests (build thread below) indicate that the preshrunk canvas, even if not perfectly ironed, will shrink some more when glued down. I didn't have any distilled water on hand for my iron when I did my test samples, so did not get all of the wrinkles out by far. I was pretty surprised how many wrinkles came out just by laying the glue coated canvas onto the glue wetted surface; and then they continued to disappear as the glue dried. I did not do very much at all to stretch my test pieces; just laid the canvas on, brushed down the center and out with gloved hand pressing gently, then rolled gently with a dry paint roller. Of coarse this pulled the canvas away from my starter edge slightly, so I had to work it back in the other direction some, but if you get things lined up well to start and roll out your canvas gradually, I don't think you have to be all that aggressive stretching. At the edges I pulled a little, just to make sure it was tight going around the radii (I wouldn't go smaller than 1/8 inch radius for 10oz cloth and you might want to use full strength glue in those locations).

That said, I suppose things might get a little amplified on a larger area than my small test, so take it for what it's worth, just another data point.

There has been some recent report of a lap seam pulling apart on Glenn's FoamStream, and even splitting of the weave in the middle of a panel on Mary's Grits, but those may have been cases where the canvas wasn't preshrunk; or perhaps over zealous stretching was used and the strain from continued shrinking was too much. Just saying, maybe stretching really hard is not needed or desired.

On a side note, I am currently struggling with the decision to stick with my original plan to use PMF, or to step up and use glass reinforced epoxy. Feel free to vote and or add to that discussion here: TPCE Wants Your Vote - Which method should I use, PMF or Epoxy and Glass?