Decoding Dicor Sealant
Part Numbers
A trip into the sealant aisle can be confusing. Here's a quick way to identify exactly what you're looking at.
🚐Dicor is the dominant sealant brand in the RV market — and for good reason. But their part numbers look like a random string of letters and digits if you don't know the code. Once you do, it's a straightforward system that tells you exactly what you're holding.
Here's how to read it.
Breaking Down the Number
Using 501LSW-1 as the example — Dicor's most common aftermarket self-leveling lap sealant in white:
What the Number Tells You
The leading number identifies the product line and channel. This is the most important part to get right before you buy. There are a couple of other numbers available, but these are the most common and my daily drivers.
| Series | Type | Notes |
|---|---|---|
| 501 | Self-leveling | Aftermarket / consumer version. Use on flat horizontal surfaces — rooftops, around vents, AC units, screw heads. |
| 502 | Self-leveling | OEM-only — same formula as 501, sold direct to manufacturers. Not typically available at retail. You may see this periodically. |
| 551 | Non-leveling (non-sag) | Used on vertical surfaces and where the roof transitions to sidewalls — it holds position and won't run. |
| 610 | Self-leveling Ultra | Premium formulation. Higher-end product for demanding applications. |
The Last Letter Is the Color
The final letter of the product code tells you the color. These are consistent across the 501 and 551 product lines. Colors confirmed on both official product pages: 501 / 551 [REVIEW]
Does It Work on Your Roof?
The 501 and 551 series are compatible with the three most common RV roof types. Here's what that means in practice:
| Roof Type | Compatible | Notes |
|---|---|---|
| EPDM (Rubber) | ✅ Yes | The most common membrane on travel trailers and older motorhomes. This is what Dicor lap sealant was originally designed for. Self-leveling 501 is the standard choice here. |
| TPO | ✅ Yes | Thermoplastic olefin — increasingly common on newer rigs. Dicor's 501 and 551 are listed as compatible. Dicor also makes TPO-specific products for larger repairs. |
| Fiberglass | ✅ Yes | Common on higher-end motorhomes. There's no separate membrane — the fiberglass is the roof surface. Dicor lap sealant adheres directly to fiberglass. No special product required for sealing vents and penetrations. |
| PVC | ✅ Yes | Less common in North America but found on some imports and older units. The 501 and 551 series are listed as PVC-compatible per Dicor's product documentation. |
Now you can read the label on the shelf and know exactly what you're getting — formula, surface application, and color — before you even open the box.
Quick rule of thumb: 501 for the flat roof, 551 for the walls. Match the color to your rig and you're done.
— Written from firsthand technician experience. Always verify compatibility with your specific roof membrane before applying any sealant product.
Stay Where You Are, We’ll Be Right There
As with all of our work, our team will come to you. There is no need to transport your camper or RV to a facility, leave it for days or weeks, only to have to go pick it up again. Whether it is in your driveway, a camp-site, or in storage, we will do our best to accommodate your needs, schedule, and location.
Just contact us, and we’ll take care of the rest.
