Saturday, April 1, 2023


Roof sealing questions and answers

Courtesy Dicor Corporation

Here are some of my most frequently asked roof sealing questions:

Our RV has an all-aluminum exterior. We’re looking for a roof sealant for use around plumbing vents and seams. What’s the best product for the job?

Dicor Products’ 501 Lap Sealant is the ideal product to use in these applications. Designed for sealing along roof edges, air vents, vent pipes, screw heads and TV antennas, it’s a flexible compound that adheres firmly to EPDM, TPO, PVC, aluminum, mortar, wood, vinyl, galvanized metal, fiberglass and concrete.

What sealant can I use for repairing cracks on other brand silicone lap sealant used on my fiberglass RV roof in the past?

When repairing cracks in a silicone sealant, we advise removing all residual sealant or tape before applying Dicor’s 501 Lap Sealant. There are many different types of sealants used on RV roofs. When cured, some may not allow for a different sealant formula to properly adhere to it, in this case silicone. Removing all of the old silicone sealant will give you the best possible surface to apply Dicor’s 501 Lap Sealant.

I need to replace my RV’s over-the-shower skylight. The roof is TPO. What sealant is right for my skylight job?

When replacing a skylight, first add a layer of butyl tape to the bottom of the skylight covering all screw holes, then seal it off with our 551 Non-Sag Lap Sealant.

Our RV is stored in an unheated garage. There’s a spot on the roof that needs to be sealed, and we’re planning on travel next week. Temperatures in our area are in the low 30s by day, and in the teens to 20s at night. Can we use Dicor Lap Sealant in these temps?

Despite the cold weather, using Dicor Lap Sealants is still an option. Just be sure to warm the container up to room temperature before use. Using it any colder can cause a delay in the curing time lap sealants need.

Dicor Lap Sealants come in 6 shades to better match your current roofing: White, Dove (Bright White), Ivory, Tan, Grey and Black. Always remember, prior to using Dicor Products’ Lap Sealants you must clean the surface of all dirt, loose paint, rust, oil and grease. Allow the surface to dry completely, then apply using standard calking equipment.

[Editor’s note: This information is provided by roof membrane manufacturer Dicor. While there’s plenty of “promotion” for their product included, some of the information and principles may be of assistance to our readers.]



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