Don’t worry, this isn’t your eyes playing tricks on you. This is a real RVer with serious RV delamination problems.
What is RV delamination?
Aluminum siding used to be the de facto choice for RV manufacturers, but most have switched to fiberglass siding because of its durability, lightweight properties, and lower overall cost. RV walls are also easier to produce and install.
They’re built like a sandwich; the exterior fiberglass and interior decorative walls are the “bread,” and in-between contains the “meat,” which is two layers of wood and Styrofoam. These materials are vacuum bonded to each other, then the “bread” in order to serve as backing reinforcements.
Fiberglass is extremely flexible, durable, and unlike aluminum, can bounce back from common hazards like road debris and hail. Unfortunately, the “meat” underneath the fiberglass isn’t quite as durable. If something impacts the RV roof or wall it might not puncture the fiberglass, but it can hit it hard enough to permanently dent the underlying Styrofoam and wood substrates.
The result is a convex air pocket that causes bonding agent failure and separation. A bubble forms over the unglued pocket, which will grow in size over time as the fiberglass-walled RV flexes with normal use. The bubble will gradually crack and trap moisture inside, causing further damage.
Bonding agent separation can also happen when water seeps in through a roof, window, or vent seam with inadequate or deteriorated lap sealant. The separation creates a river of moisture and the result is a soggy RV “sandwich” eventually consisting of unsightly blisters, bulges, and waves on the outside and irreparable wood rot on the inside.
Most owners don’t recognize the signs of RV delamination until it’s too late. Fiberglass RV walls can look smooth on the outside while real damage is unseen. When the problem becomes obvious, repair is usually expensive and often impossible to fix.
Recognizing and repairing RV delamination
Whether you own a fiberglass RV now or you’re shopping for a used one, it’s important to know the signs of this expensive problem. First, do a thorough walk-around in direct sunlight and closely inspect the side, front and rear RV walls as well as the areas around windows and roof vents.
The fiberglass should be flat and smooth. If you notice any waves, bubbles, or creases, press them with your finger. If the area feels spongy, you have probably spotted RV sidewall delamination. Double check by tapping it lightly with a plastic utility serving spoon or other implement.
A hollow sound indicates delamination. When the RV is parked in shade, notice how the waves and bubbles react. If they get smaller and flatter, that’s another indicator of RV sidewall delamination.
If you’re just browsing the market for a used fiberglass RV, now’s your chance to run. You do not want to own a RV with delaminated sidewalls, even if the owner is giving it away for free.
The repair costs rarely justify the effort and expense of repair (however there are exceptions, so keep reading). If water has permeated RV sidewalls, it may have already weakened the RV’s structural integrity. Mold spores can fester on the damp inner wood layer and cause health problems for the owner. You won’t know any of this is occurring without peeling away the outer layer.
My RV has delaminated. Now what?
The most common cause of the delamination problem is an owner failing to periodically re-seal seams with lap sealant. As a consequence, RV insurance companies and extended warranties don’t usually cover RV delamination repairs.
If you’re in this unfortunate situation but the damage is relatively minor, you can try a delamination repair kit. These kits cost $200 to $300 and include a heavy-duty, marine-grade bonding system that can be used to re-glue the fiberglass to the underlying layers. They come with syringes and tubing for injecting the sealant into tight spots. However this solution only works if the inner layer is free from water damage.
If the problem is big but you have a never-say-die attitude, a DIY approach to RV delamination repair is possible. Notice how this hearty iRV2 Forums member documented his entire repair job for anyone brave enough to try it themselves.
Have you experienced sidewall delamination on your rig? If so, what did you do about it? Let us know, because there are many fiberglass RV owners who would appreciate reading about your experience.