Your RV Series: Fiberglass or Metal Siding?

Should I get a metal sided RV or a fiberglass sided RV? A lot of would-be RV Owners ask that question everyday. I am not in a position to help you choose one over another so, the choice is ultimately up to you. This guide is being written to help guide you through the selection process, listing the pros and cons of each type of geposition.RV Wall geposition gees in many forms and types. Early RVs had walls built much like a house, stick frame construction made with actual 2x4 lumber on 12 or 16 inch centers. Furthermore, some early manufacturers used hardwood in place of pine. In either case, these trailers were quite heavy and gave less living space as the walls crowded into the RVs interior. New production methods and materials have allowed RV manufactures to build and install walls that are much thinner but have the same insulating qualities and strength of the stick-built RV of years gone by. Two wall types gee to mind when thinking about current RV structures. They can be identified by the finish on the outside surface of the RV... metal sided and fiberglass.The metal sided offerings from RV manufacturers still have the stick frame construction and fiberglass bats of days gone by but, Instead of the walls being 4 plus inches thick, the framing has been reduced to 2 inches and extra support is given around, not only window and door openings but just about anywhere a water line, cable, or something else must cross from the outside and to the inside of the structure. Advancements in the properties of insulating materials have allowed for better insulation in less space, without gepromising the ability to work as designed. It is seldom that the sub-exterior of these walls is covered in plywood or any kind of vapor barrier , before the metal is installed so the fiberglass bats have direct contact with the inside of the metal finish. This can lead to moisture problems but often only because the seems are not fitted tight enough on the metal siding or there is a water seal problem on the roof. In all fairness, moisture is everywhere. Even newspaper has a moisture content of 10 to 15%!Fiberglass siding gives the RV owner several advantages over metal siding but also has it's limitations. The majority of fiberglass walls are manufactured with a process called Vacuum Bonding. That is where the frame, usually made of 1 or 2 inch aluminum tubing , is filled with high density styrofoam firmly sandwiched between the inner and out walls. The outer wall, being made of Fiberglass and the inner wall a finished panel to match the interior of the unit. Current offering include the addition of a thin piece of wood panel between the fiberglass and styrofoam, as RV manufacturers understood that the fiberglass skin itself was not strong enough to deflect many projectiles. The insulating qualities, as well as the strength of such a wall are hard to match. Moisture is seldom a problem, provided the RV is well taken care of, and since it has a smooth outer surface, it is easier to keep clean. On the down side, if damage is done to the outer wall, such as, lets say, surviving a moderate to major hail storm, the damage may not be immediately detected. This will eventually weaken the structure making it necessary for timely repairs. Let me explain in further detail. When something hits the exterior of a fiberglass sided RV it does NOT (in the majority of cases) puncture the fiberglass, leaving a crack that would show obvious damage. The fiberglass is flexible enough to give under the pressure of the hail strike. Where the damage actually occurs is underneath the fiberglass where you can't see. The styrofoam, made up of a lot of small air pockets, is crushed. Immediately after the strike, the fiberglass once again assumes its normal flat shape. Unfortunately, the wood panel backer and styrofoam underneath does not. It leaves a pocket of air where the styrofoam or styrofoam and plywood backer used to be. This is called delamination. This can be seen on older fiberglass sided units that have seen their share of damaging weather, as well as new units that have experienced a drive through the foul elements. It weakens the wall and, if left unrepaired, will eventually grow, as the flexing and movement of the RV causes the two surfaces to work away from one another. You may first notice the delamination as small blisters... Dime sized or larger. They can quickly increase in size.... over a period of weeks or months. Exposing the damaged surface to the sun will increase the size of the
blisters as well, as the air pocket underneath is heated and expands. DO NOT WAIT.. GET IT FIXED OR HAVE IT LOOKED AT BY A gePETENT RV REPAIR SHOP AT THIS STAGE! If left un-checked, the thin, loose fiberglass sheet or skin starts to crack at stress points, allowing water, dirt, and dust to get in between the opposing surfaces. Finally, the fiberglass peels off in large sections, exposing the foam. Some RV Repair shops just cover over the existing delamination with a new sheet or skin of fiberglass. This does not fix the problem, it only covers it. The ONLY two ways to properly fix a delamination problem is to 1) inject a bonding agent into the blister and then apply pressure so the area at the blister retains it's original shape once it is cured, or 2) Replace the entire wall with a new one. Because the damage may go preliminarily unnoticed, such as in the case of an insurance adjustment, it is VERY IMPORTANT that you make the adjuster aware of your knowledge of possible future delamination and the consequences! I've recently done estimates on brand new 2010 units that have seen hail damage at the 2009 Sturgis Bike Rally. (If you were there, you know what I am talking about!) Some of these estimates include geplete sidewall replacements... The only evidence I needed was several of those quarter-sized blisters that I was explaining earlier. The majority of insurance gepanies are aware of these problems and will want you to take a concession or a gepromise. That's between you and the insurance gepany... I just report what I know. The crating, shipping, and delivery of these walls alone is astronomical, let alone the tools and materials needed to acgeplish the replacement. Exposing the damaged surface to the sun will increase the size of the blisters as well, as the air pocket underneath is heated and expands.How to detect unseen damage to vacuum bonded walls: Hail damage can take place to several sides of an RV during any one occurrence. Some by the direction of the storm as well as the direction the RV was parked... These are usually direct hits, affecting one or two sides. It may also experience damage to a third side by hail that has bounced off of objects around the site, such as other vehicles, etc. To have all 4 sides damaged is rare but does occur from time to time.1) Park your RV so that the suspected side having damage, is in the sun. 2) Watch the siding throughout the afternoon to see if any "welts" or "blisters" develop. (In many cases, you may already see these.)3) Make note of the bumps you have detected on a piece of paper or mark them with pieces of masking tape for more tests later. (They may hide on you when the weather cools off or the sun is no longer present.)4) Gently press on the bumps... If they DO NOT feel solid and spring back to the touch, IT IS THE BEGINNING STAGES OF DELAMINATION.5) Repeat the process in #4 AFTER the sun is not shining on the affected panel and after the fiberglass surface has been allowed to cool. (NOTE: Some of the bumps that you have marked with tape may have disappeared.) As you gently press, do the bumps or areas where the bumps used to be when the sun was shining on the panel, give alittle? If it feels solid, but it is an area that was marked by tape earlier, chances are that the delamination is taking place between the fiberglass and wood backer. If you can push the fiberglass gently into the surface, the wood panel backer has been gepromised as well, meaning the damage goes into the styrofoam.I will take this time to explain that some RVs with vacuum bonded walls will leave the factory with defects from time to time. It's a fact of life... They are either not caught at final factory inspection or occur during transport. When buying a new RV with Vacuum bonded walls, check the exterior over real good before purchasing! On the other hand, I've personally seen brand new trailers gee in with fiberglass patch-n-paint jobs where a router got away from a builder/worker and scored the side of a unit being built or perhaps someone hung the awning in the wrong place and patched and covered the holes and sent it down the road. These are not "defects"... and the manufacturer should be held accountable. Too often they are discovered well after the warranty period has expired. Summary of METAL Siding:Pros: Less expensive to build and buy Damage to the siding is immediately detectable Only the damaged pieces need to be replacedParts can be crated and shipped easily Cons:More prone to moisture within the wallsNot as strong as it's fiberglass counterpartsProne to damage where lighter object strikes are encountered, such as a stray basketballSummary of FIBERGLASS Siding:Pros:Easy to maintain and care forStronger, durable and keeps it strength and shape where lighter object strikes are encountered, such as a stray basketball (Provided there is no unseen/undetected damage)Cons:Repairs in many cases require replacement of the geplete wall. Severe damage often goes unnoticed until it is too late.Shipping of replacement parts is very expensive.In closing, I do not take sides with RV manufactures, RV owners, insurance gepanies, or anyone else. I only write these guides to let you know the facts that I've gained from working in this industry. Knowledge is empowerment! I hope you've enjoyed this guide. Check out my other guides for more RV related materials. If you have any questions or gements, drop me a line.