WINNEBAGO EKKO – Roof Seal and Skylight Maintenance

by

Roof Seal and Skylight Maintenance for WINNEBAGO EKKO

The Winnebago Ekko’s roof is a hybrid system that demands more attention than a standard Class B van — you’re dealing with the factory Ford Transit metal roof up front, a fiberglass composite rear cap extension stitched to it, a Fantastic Fan cutout, optional solar panel penetrations, and the Thule HideAway awning rail bolted along the driver’s side. Every one of those transitions is a potential leak point, and the rear cap-to-roof seam is the most notorious failure area on this model. Dicor lap sealant is your primary weapon, but knowing where to look and how to prep surfaces correctly is what separates a repair that lasts one season from one that lasts five. Plan for a full day on a dry day with temperatures between 50°F and 90°F — Dicor won’t cure properly outside that range.

Required Parts

Step-by-Step Instructions

Step 1: Set Up Safely and Do a Full Roof Inspection

The Ekko sits tall on the Transit 350 HD platform — roof height is roughly 9.5 feet unladen, so a six-foot stepladder won’t cut it. Use a combination of a sturdy eight-foot ladder and a roof walk board or foam kneeling pad to distribute your weight. Never step directly on the fiberglass rear cap extension without a board underneath you; it will crack under concentrated foot pressure. Start your inspection at the front Transit roof and work systematically rearward. You’re looking for five specific things: cracked or separated Dicor at any penetration (Fantastic Fan ring, antenna bases, solar conduit fittings), lifted or bubbling EternaBond tape at seams, soft or spongy spots in the fiberglass cap indicating delamination from subsurface moisture, separation at the rear cap-to-Transit-roof transition seam, and any rust staining on the metal roof section suggesting standing water. Use a flashlight at low angles — it makes cracks in sealant pop visually. Photograph every suspect area before you touch anything so you have a before reference. Pay special attention to the four corners of the Fantastic Fan curb, which flex slightly when the van body twists and tend to crack Dicor within the first two seasons of ownership.

Step 2: Clean the Entire Roof Surface

Adhesion is everything in roof sealing work, and the Ekko’s roof accumulates a specific combination of road grime, tree sap, oxidized fiberglass residue from the rear cap, and old sealant film that will sabotage any new product you apply over it. Mix the Dicor rubber roof cleaner and degreaser at the full-strength concentration for your first pass — diluting it is for maintenance washes, not pre-repair prep. Apply it in sections using a soft-bristle brush, working front to back so dirty runoff doesn’t contaminate areas you’ve already cleaned. Scrub the rear cap-to-roof transition seam thoroughly; this area collects a waxy oxidation residue from the fiberglass that is invisible but will prevent Dicor from bonding. Rinse each section completely and let the roof dry for a minimum of two hours before proceeding. Do not use petroleum-based solvents or acetone anywhere on the fiberglass cap — they’ll lift the gel coat. For stubborn old sealant residue that won’t lift with the cleaner, use the plastic putty knife to gently scrape it away; metal scrapers will gouge the EPDM membrane on the Transit roof section and create new leak points. The roof must be completely dry and at ambient temperature before any new sealant touches it.

Step 3: Remove and Replace Failed Sealant at All Penetrations

Work through every penetration point on the roof individually. The Fantastic Fan mounts on a raised ABS plastic curb — Dicor is applied around the entire perimeter where the curb flange meets the roof. Use the plastic putty knife to peel away any cracked, yellowed, or lifted Dicor here; don’t try to caulk over old failed sealant because the new material won’t bond to the chalky surface of aged Dicor. If your Ekko has the solar roof prep package, you’ll have a conduit chase fitting near the rear of the Transit roof section — this is a common overlooked leak point that feeds water directly into the driver-side wall cavity. Load the self-leveling Dicor lap sealant into the drip-free caulking gun — the trigger mechanism on a standard gun will make a mess with this low-viscosity product, so the drip-free model prevents sag between cuts. Apply a continuous bead around each penetration, starting at the uphill (front) edge and working around. Self-leveling Dicor will flow and settle into low spots naturally on a flat roof; don’t try to tool it smooth with a finger. Apply it at least two inches wide on all sides of each fitting. The Thule awning rail mounting bolts along the driver’s roofline should each be individually capped with a dab of Dicor — lift the awning arm and check each bolt head carefully.

Step 4: Address the Rear Cap-to-Roof Transition Seam

This is the most critical seam on the entire Ekko and the one Winnebago’s own service documentation flags for annual inspection. The fiberglass composite rear cap extension is bonded and screwed to the Transit’s factory roof structure, and the seam runs laterally across the roof roughly above the rear sleeping area. The thermal expansion rates of fiberglass and steel are different, which means this joint moves slightly with every significant temperature change — it’s a live joint, and it will eventually crack any rigid sealant. Start by removing all existing sealant along this seam with the plastic putty knife, working carefully so you don’t damage the underlying membrane. If the seam gap is wider than a quarter-inch or shows signs of repeated resealing over multiple layers, apply EternaBond RoofSeal tape as your primary repair material rather than Dicor alone. EternaBond’s butyl adhesive layer bonds directly to both fiberglass and the EPDM membrane and handles joint movement far better than sealant by itself. Cut a length of the four-inch tape to span the entire seam plus six inches of overlap on each end. Peel the backing in stages and press it down firmly, then use the J-roller with firm, overlapping passes to eliminate every air bubble and achieve full butyl contact. Any lifted edge on EternaBond becomes a water scoop — the J-roller step is non-negotiable. Finish with a bead of self-leveling Dicor over the tape edges.

Step 5: Inspect and Reseal the Fantastic Fan Installation

The Fantastic Fan on the Ekko is factory-installed and uses a standard 14-by-14-inch roof opening cut into the Transit roof panel. The fan’s ABS plastic curb is sealed to the roof with Dicor at the factory, but the curb-to-lid hinge area and the four corners of the curb are the first points to fail. Open the fan lid fully and inspect the inside of the curb — water intrusion here shows as rust staining on the steel roof pan visible from inside the van, which you can verify from the ceiling interior. If you see rust staining on the headliner or ceiling panel around the fan opening, you likely have an active leak that’s been running for more than one season. On the exterior, apply fresh Dicor around the entire curb perimeter, feathering the uphill edge especially wide — at least three inches — because rain water flows front to back at highway speeds and the front face of the curb takes the brunt of it. Check the four corner screws that secure the fan curb to the roof; if any are loose, re-torque them snug before applying sealant, because Dicor over a loose fastener will not stop movement-driven leaks. Do not over-tighten — you’re threading into sheet metal and plastic, and stripped holes require backing plates to fix properly.

Step 6: Apply EPDM Roof Coating to the Transit Roof Section

The factory Ford Transit roof on the Ekko is coated from the factory but benefits significantly from a fresh EPDM rubber coating every three to five years, especially in high-UV climates. This step applies only to the metal Transit roof section — do not apply EPDM coating to the fiberglass rear cap, as it won’t bond correctly to gel coat and can trap moisture beneath it. Before coating, apply the Liquid Rubber EPDM/TPO primer using the three-inch roller, covering the entire Transit roof section evenly in a thin coat. Let the primer flash off for the time indicated on the can — typically 30 to 60 minutes depending on temperature and humidity. The primer is what makes the EPDM coating bond permanently to the existing roof surface rather than peeling up after the first freeze-thaw cycle. Apply the EPDM rubber coating in two thin coats rather than one thick coat; a thick single coat skins over on top while staying wet underneath, leading to blistering. Roll it in a consistent direction on the first pass and perpendicular on the second pass to eliminate roller texture lines and ensure uniform coverage. Keep the coating at least two inches away from any Dicor sealant beads you’ve already applied — the two products are compatible but overlapping creates an unnecessary thickness transition that can lift at the edge.

Step 7: Final Inspection, Cure Time, and Water Test

Dicor lap sealant needs a minimum of 24 hours to skin over and 72 hours to fully cure before the van should be driven through rain or washed. The EPDM coating needs 48 hours minimum between coats and 72 hours before water exposure. Do not park under trees during the cure period — bird droppings and leaf tannins can stain and partially inhibit cure on both products. Once cure time has elapsed, do your water test before considering the job done: run a garden hose at low pressure along each sealed seam and penetration for a full two minutes while someone inside the van watches the ceiling and walls with a flashlight. Start at the rear cap-to-roof seam and work forward. Pay specific attention to the area above the driver-side Xantrex inverter compartment — water intrusion at the forward driver-side roof edge can track along the wall and reach the Xantrex Freedom XC 2000W unit in the under-bed compartment without showing obvious ceiling staining, and water in that compartment is a serious electrical hazard. If you detect any interior moisture during the water test, mark the exterior location immediately and reapply sealant before calling the job complete. Log the date and products used on a card stored in the Ekko’s documentation compartment — your roof maintenance history is valuable for resale and for tracking how long each repair actually lasts.

← Back to Top 20 Class B RV Models