HANDLING MOISTURE in RV's
Awning supports are difficult because they are almost never sealed properly. Installers usually (but not always) make a big deal out of locating structural members inside the walls for attaching the (main) end pieces (upright supports). Then they just screw them in through the outer skin without any gasket, backing sealer or caulk in the holes. Further, corrugated aluminum and fiberglass skins are usually badly crushed in the process. The thin moulding strip that holds the awning fabric against the wall (along the top) also has no backing and the many screws are just run through prepunched holes with no effort to locate what other structural members might be behind there.
If you're going to have an awning installed, you might get an installer to do the job right, but it's unlikely. Usually they'll agree with everything you say, then ignore you and do it "quick and dirty." You'll be better off getting a friend or two to help. It's easy if you read the instructions. It'll take up to two days (if you do it properly and spend some time figuring out where the backing behind the skin really is) instead of a couple of hours; but you won't have any leaks and it will be secure. (A friend and I were sitting at the RV park when the truck showed up -- from one of the really, really big RV stores -- at a neighboring site. The men got the job done quickly -- too quickly -- and while they putzed around measuring the outside, we never saw them go inside the RV. We knew we were in for a treat and sure enough, when the techie reached up with the hook and pulled on the awning, it came right off the RV.)
Awning leaks are really nasty, because water goes into the inner wall and usually isn't detected until it's done severe damage. Sometimes water will work its way down the inner wall (through all those screw holes that aren't really screwed into anything). Often, water from awning leaks eventually works its way into the inner RV wall through a window frame. Most RVers then assume the frame is the source and spread caulk all over the window and wonder why it won't stop leaking.
If the awning is already installed, removal and reinstalling is a real chore. This is a case where you might get away with caulking if you do it right. Remove each awning strip screw (just one at a time), fill the hole with caulk and reinsert a better screw as above.
CAUTION! Most of these screws only go through a thin aluminum or fiberglass skin. If you tighten them too much, you'll just make a bigger hole. You can repair with an insert or pop rivet, but you don't want to.
If you're using a quality sealer in an easily-handled tube with a fine tip, you can also apply just a bit around the edge of each screw head. Examine main support bolts before diddling with them. You may be able to remove, caulk hole, and replace one at a time, or you may be able to partially unscrew and apply caulk to threads and retighten.
Carefully caulk around the edge of support arm plates. Don't try to apply huge globs at one time. Try to get a thin bead into, not just all over, crevices; then go back and add more later. Similarly, apply a thin bead of caulk along the top and bottom of the long horizontal strip.
Another superior caulk for long runs and tight crevices is "SEAL ONCE." It's very sticky but "creeps" into thin cracks. It also works on wet and oily surfaces, which helps. It stays tacky for days; don't fiddle with it until it sets. It's probably the most effective caulk made. Sold in some RV stores and many boating stores (used in wet bilge compartments).
Possibly (but arguably) the best coating is a professionally-applied layer of vinyl sheeting (the so-called rubber roof). It's expensive, but it is, in effect, a new roofIF INSTALLED PROPERLY! Careless installation, even by a professional, can end up with you being even worse off. To install it properly, everything is first removed from the roof and replaced when the job is done. The problem with this is that when basic problems are not repaired before the new roof is laid on, the new roof isn't affixed properly, the vinyl is cut improperly and things are replaced and not sealed properly as described above, you're right back where you started.
More on Rubber Roofs:
"Dicor Corp." makes most of the EPDM (Ethylene Propylene Diene Monomer) material used in so-called rubber roofs. (Dicor calls it Brite-Ply.) Literature is provided with new RVs. Most people never pay attention to it, if the dealer even bothers to pass it on. Used RVs also seldom have the information.
You can get information sheets from Dicor Corp., PO Box 1806, Elkhart, IN 46515. (219) 264-2699. Best way is to use their Web site at www.dicor.com for much more extensive and timely information.
A critical point: It is critical that no petroleum-based solvents, harsh abrasives, or citric-based cleaners be used on rubber roofs! Doing so can cause irrepairable damage. (And seems to be the real cause of most roof complaints, followed closely by sloppy installations. (What do you expect from installers working for minimum wage?)
Petroleum-based solvents are especially damaging. They can penetrate the membrane and dissolve the adhesive underneath. The result can be bubbles or even large, loose patches.
Dicor makes the material. They do not apply it to the RV. The RV manufacturer (in some cases RV dealers) do that. The EPDM membrane, as supplied by Dicor, should last 30 or so years (possibly longer than you will), if properly installed and taken care of.
Most blisters are small, few in number and are only cosmetic. Since they are on the roof, they are not all that visible. Cutting slits or poking holes in them and injecting sealer or caulking can lead to water leaks and further damage. If they are left as is and not carelessly torn, you are usually better off.
If you insist on fixing bubbles (and you shouldn't), make sure you use only sealers that specifically state: "butyl rubber" caulking/sealant.
There are a lot of sealers, caulks and care products that have something like "Okay for rubber roofs" on the label. Do not accept that as a fact.
Insist on butyl rubber ingredients for sealers and caulking.
When attempting to fix (flatten) bubbles, don't just start cutting away. Get some disposable medical syringes from a pharmacy. Load one with some of the butyl rubber sealant, carefully inject some and carefully massage the bubble. Once it's flat (this can take a lot of massaging, hey, I warned you), put a piece of cling wrap or wax paper over it and put a weight on it until dry. You might be successful and might not.
One place you can successfully use the butyl rubber sealant (and really do some good, rather than just screw around with bubbles) is at the edges of the roof membrane. Roof vents, plumbing vent pipe holes, roof edges under trim strips, air conditioner openings, etc., are all subject to loosening at the membrane's edges. (This is often caused by a sloppy installation.)
Refrigerator roof vents are especially troublesome. Installers often cut the opening through the membrane rather casually. They then fold it over the edges of the vent hole and don't adequately secure it. Over time, and with the heat that flows up through the vent, air flow can be restricted (and it doesn't take much to cause the all-too-common complaint that the reefer isn't cooling properly).
RV manufacturers do (frequently) an absolutely lousy job of installing refrigerators. Poor ventilation is (experts say) the primary cause of refrigerator failures. I recently heard of a refrigerator ruined because the manufacturer simply cut a hole in the roof over a reefer and let the rubber-covered plywood drop on top of the reefer. No venting equals no reefer. You might want to see what's really under your roof vent.
Maintaining the rubber roof: Mild dish washing detergent (Dawn, Joy, etc.) should do the job unless parked under really grody trees. Use a mild-bristle brush. Do not use harsh abrasives or a stiff brush. A sponge is okay for scrubbing, but a brush is needed when rinsing. (Using a sponge when rinsing just smooshes the dirt around and doesn't get rid of it.)
Full-strength household bleach is good for stubborn stains (but don't slop it all over, or it will run down the sides and screw up your wax job).
Dicor makes a safe cleaner. Their "RC100 Dicor Synthetic Roof and General Purpose Cleaner" works and attacks stubborn stains when used full strength.
Mineral spirits can help with stubborn stains, but, you can't spread it over large areas and must work very fast (spot clean and flush it off quickly) or it can deteriorate the membrane.
Another good protectant is "303." It will not harm rubber roofs and will keep crud from accumulating, but, Dicor insists it isn't really necessary. (Does this remind you of the days when Andy Granatelli sold STP? He finally admitted it didn't really do any good, but didn't do any harm either.) What the hell, it's your money. "303" can be used for lots of things.
Something to think about then:
"Hitcharama RV" in New Jersey uses a product called
"Reliable Cleaner" for all their coach preparations.
It contains Glycol-Butyl-Ether, Non-ionic Surfactants, Sodium
Metasilicate and is water based. Might be okay?
Properly applied, in successive coats, using one gallon per 10 feet of roof length, this stuff prevents leaks and enormously improves insulation. The key is "properly." First, you've got to properly seal everything up. Then you have to scrape off the loose crud, globs of old asbestos coating, flakes and such. Use a cleaner to remove mildew. Fortunately, you don't have to remove all old coatings, just the shabby stuff. Good elastomeric will cover a multitude of old sins.
Seams, cracks, edges of patches and the like should be treated first. Building supply stores will have a 4-inch wide fiber mesh tape (usually yellow or black) made for this purpose. If you use the "Liquiply" brand of elastomeric, they have a matching caulk that comes in gallon cans and caulking-gun tubes. It's the same as the coating, just thicker.
Spread a layer of this all along the seam, for example about 6" wide. Embed a length of the tape in it with fingers, putty knife or similar. Let it dry. Then spread another layer over it and work it well into the tape. Touching up is easy. Just add more after the previous layer dries. (If you keep spreading or brushing this stuff too long, it starts to dry and gets hard to handle.) If you're using the Kool Seal brand, you won't have matching caulk, but the coating itself will do as well. You'll just need to spread more layers because it's thinner.
Finally, coat the whole roof with successive layers. You want a nice thick coat, but don't lay it on too thick at one time or it'll take forever to dry. The base material for elastomerics is a latex. If it gets rained on before it dries, you've got a mess. The stuff can be sprayed on, but you'll get it all over everything. Brushing works well. Some people use a paint roller for even coats but it's hard to spread because it's so thick. One gallon per 10 feet of roof length (don't deduct for A/Cs, vents, etc.) will allow about three good coats, even if you use some for patching seams.
Properly done, you won't have leaks and in our test we measured (albeit unscientifically) a 20-degree reduction in roof temperature during the summer. That's significant.
You won't find any technical references that I know of. Most
repair shops won't even attempt these repairs except at great
(prohibitive) cost. It can cost more than the RV is worth. Still,
sometimes, for various reasons, people do successfully rebuild
such a mess.
While you're doing all this, it's obvious you need the RV under a shelter or have a large tarp you can batten down during inclement weather. As you go through this drill, the interior framing should start to dry. While that's happening, you should still be inspecting and examining.
Don't just initially tear out anything that appears rotted. Some dry-rotted wood can be "rescued" -- at least to some extent. The product I use is called "Git Rot" and is available at good marine stores or from "West Marine" (www.westmarine.com) or (800)-boating. I recommend you call West Marine and get their "master catalog." There's a whole bunch of products in there that most RVers don't know about. "Git Rot" is a two-part mix (like an epoxy, but thinner). Much dry-rot can be saturated with this. It creeps through the wood and does a "molecular thing" with the cellulose that's left. If properly done, the remaining wood is like an epoxy and can be cut, drilled, etc. Added pieces of wood can be affixed to it and you can, if careful (lucky) end up with a rather stout structure. Git Rot is tricky to use. Carefully follow the detailed instructions! West Marine has a few other similar products as well. Another favorite dry-rot product is "Poly All" at www.polyall.com/wood.html.
Once you open up the outer shell, and locate the rot, then, before you start using Git Rot (or similar), you need to open up the inner shell (at appropriate places) as well. Cut away the thin paneling on the inner RV. Save the pieces for patterns when replacing. Once removed, you will REALLY see the rot that might be in there -- and be able to repair it.
Ref: Fiberglass outer skin. If you do the job right, you should be able to save the outer fiberglass skin (because it's hard to find). If you're lucky, you'll have a preformed end cap. The entire end cap can be removed to get to the structure (not hard, just laborious). You'd want to "beef" the cap up anyway and removing it makes getting to the structure easier. If you've just got fiberglass siding butted together at the corners, try to save it. Finding fiberglass that matches your RV's style will be difficult. First, try the RV manufacturer. Also try calling local RV shops and ask where the damaged "junkers" go. Check "yellow pages" for fiberglass distributors (who can refer you to retail sources). You might call "Wabash National Parts" (800) 621-7949 for a clue. Also check www.all-rite.com/fiberglasssiding.html for what they have available.
First things first. You've got to keep moisture from getting in. After that, you deal with what you make on your own.
Then reduce the water you make on your own.
Then insulate the thing properly.
And, then, you shouldn't need extras.
This article courtesy Phrannie.org.