RV Rubber Roof Repair in Yorba Linda

EPDM chalks. That white residue streaking down your sidewalls after rain is the EPDM surface oxidizing and washing off, and it is normal behavior for the material. TPO does not chalk and generally stays a brighter, cleaner white. EPDM has a slightly softer, more matte feel. TPO is stiffer and more puncture resistant, and its factory seams are heat welded rather than adhered.

The reason it matters is chemistry. EPDM adhesives and primers do not bond to TPO. A patch applied with the wrong system looks perfect on the day and lifts at the edge within a few heat cycles, which is when the owner finds out. TPO can be heat welded, which produces a permanent homogeneous joint, and that is the correct repair for a tear in a TPO roof if the material around it is sound.

We identify membrane before quoting, every time. It costs nothing and it is the difference between a repair that lasts and one that gets redone.

Because adhesion needs a clean surface and old sealant is not one. Cured lap sealant that has cracked and shrunk has a dusty, oxidized, contaminated surface. New sealant applied over it bonds to that contaminated layer, and the whole assembly then peels off as a unit, taking the new sealant with it.

On a chalked EPDM roof the same problem applies to the membrane itself. Chalk is loose oxidized material. Anything applied over it is bonded to dust. Preparation on an aged EPDM roof means washing with a suitable cleaner, scrubbing the chalk off, and confirming a clean surface before a coating or a sealant goes on. That preparation is a substantial share of the hours in a recoat quote, and it is the part that a cheap quote leaves out.

Silicone deserves its own warning. It is common on RV roofs because it is easy to buy and it looks like it works. Nothing bonds to a silicone contaminated surface, including new silicone. It has to be mechanically removed, which is slow and tedious, before any correct repair can be made.

• Old cracked sealant removed back to the flange and the membrane
• Chalked EPDM washed and scrubbed until the surface is clean
• Silicone mechanically removed wherever it has been used
• Membrane specific primer where the product system calls for it
• Self-leveling on horizontal flanges, non-sag on vertical faces
• Reinforcing tape over seams and tears before sealant on EPDM

A full recoat is a system, not a paint job. The roof is washed and the chalk is removed. Every penetration flange is stripped of old sealant and resealed. Seams and any tears are reinforced with membrane compatible tape. A primer is applied where the coating system requires one. Then the coating goes on in the specified number of coats at the specified wet film thickness, with cure time between coats.

Wet film thickness is where most coating jobs fail. Roof coatings are specified by gallons per square foot for a reason, and a coat applied thin to stretch the material gives a fraction of the service life. We apply to specification and we tell you the coverage rate we are working to.

A recoat is appropriate on a membrane that is aged and chalking but structurally sound over sound decking. It is not appropriate on a membrane with widespread tears, on decking that is soft underfoot, or where water has already reached the interior. In those cases a recoat is money spent to postpone a membrane replacement by a season, and we will tell you that rather than take the job.