Even before I removed our leaking water heater, we could smell mildew. After removing it, I found the leak had wet the surface on which the heater had rested, on either side of the heater. This surface, seen in the attached interior view, is made of corrugated fiberboard (normal shipping box cardboard). After I applied vinegar to the mildew and while waiting for it to dry, I got to wondering: Why was this material used here? Since all plumbing can leak, a fiberboard surface exposed to potential leaks seems about as appropriate as the soaked fiberboard shell-over-batting insulation on our busted water heater. On our yet-to-be-installed bran new heater the manufacturer had replaced the old model's fiberboard shell-over-batting with a solid cocoon of rigid Styrofoam.

As near as I can tell, the structure beneath the mildewed fiberboard seems to be nothing more than the left side wheel housing. Does anyone know whether that's correct?

I am guessing the fiberboard may have been intended to serve as sound deadening, or as thermal insulation, or both. Does anyone know better?

Whatever the fiberboard's purpose, another question is whether I ought to replace it with some water- and mildew-resistant material that serves the purpose(s) as well or better.

If the fiberboard was intended for sound deadening, one substitute material that came to mind is Dynamat, which is waterproof and effective (I've used it to silence a noisy stainless steel espresso knock-box) but Dynamat is pricy. Regular asphalt padding for automotive sound deadening may be less expensive but I don't know whether it would be any more mildew resistant or whether it would get messy in this application (the wheel housing extends left and right into cabinets in which we stow kitchen items).

If the fiberboard was for thermal insulation, there's hardly room for a lot of R-value but maybe some thin closed-cell foam would insulate just as well or better than fiberboard and be more mildew resistant. “Volara” appears to be one such foam. The local hardware store sells 26x72” black sheets of it in 0.25” thickness as “camping pads” (for $28 + tax); an Ebay seller has 57” wide white sheets in either 0.125” or 0.25” thickness, which he markets for use under Vinyl for gaming table pads ($1.99 per lineal foot + $9.95 shipping for the first foot and $1.15/add’l foot); and I know it’s also used in spa covers but doubtless in thicker sizes. There is zero clearance leeway so thickness matters; the fiberboard was probably about 5/32” thick when new but of course fiberboard is rigid compared to Volara. Then there's Neoprene, which is just a bit more expensive than Volara at the hardware store. I wish I could just reuse the rigid Styrofoam packing in the box containing the new water heater; there seems to be enough to cover the wheel housing, but it's about an inch thick and probably would squeak incessantly.

Any suggestions? Folks with older Hi-Los than our may have made similar mods, while those with newer models could tell me what material was installed instead of fiberboard over the wheel housing on their trailers.

Thanks.

Jeff
1993 Funlite

Attached Files

fiberboardunderH2Ohtr.pdf (538.1 KB, 56 views)

My 95T doesn't have anything over the metal wheel housing, I haven't looked at the 2209T enough to remember yet but I don't think that it does either, that covering may not be factory installed.

Good point! Notice the tape job on the covering - that doesn't strike me as Hi-Lo's normal MO, either. If I could raise the previous owner from the grave, I'd ask (we inherited it).

If everyone else has bare metal, I wonder if they have any problems with it. This trailer spent winters on the Alberta prairie, so maybe it was just a home-made frost-liner, but now that we've imported it to western Washington State, we may not need that, or anything.

Jeff

I would bet, if there isnt physical damage under that box, that it was a source of cold air, or air exchange. bare metal (like an uninsulated garage door) transfers heat/cold massively when it is COLD out. so one owner might have thought even an air space would keep the hot water from cycling as much, wasting fuel.

Newer campers I've been lucky to guest camp with, with have remote lighted hot water heaters, where when you think you're gonna shower or wash dishes you light water heater and wait 5 minutes, & you have hot water. Then shut off when done (waste almost no gas the rest of the day or night just keeping water you arent using, HOT.) I havent tried any camper in absolutely cold weather (daytime highs at or near freezing). But I have camped and been cold in campers where it got to freezing overnight, lol.

from below there isnt a hole or something where a tire blowout caused damage or anything that they are hiding or semi-repairing with this cardboard box they made?

__________________
From Kansas: 29ft '95 5th, converted to toybox in rear, by Hilo. Pics soon, Some Here.

Nope, nothing there but an intact wheel housing. I think your other theory about why the owner put the cardboard there in the first place is very probable - to serve as a simple non-conductive insulator between the HWH and the otherwise bare metal of the wheel housing, because that would make perfect sense for a trailer like this that spent its time on the cold Albertan prairie and trips through the Rockies. Perfect sense, that is, assuming the HWH never leaks. Plus, if the reason had been a hole, they'd presumably have simply plugged the hole instead of going to the much greater bother of fashioning and installing a complete surround for all four interior sides of the wheel housing.

I've killed the mildew, so I'm not going to do any mod unless it starts stinking again; in which case I'll cut out the part of the cardboard under and near the HWH, replace it with some thin closed-cell foam, and call it good.

Thanks to all for the suggestions.

jj

You fix leak or replace HWH? I had mine welded, one tiny pinhole, 40 bucks instead of 400.

Mildew is a PITA, if you got it dry it probably will be fine until it gets wet again.

__________________
From Kansas: 29ft '95 5th, converted to toybox in rear, by Hilo. Pics soon, Some Here.