Mia and I have owned Clifford the Big Red Van for almost four years now. As with most things as they age there is some TLC/maintenance that needs to be done to keep things running in tip top shape. I’m not talking oil changes, tire rotations or anything like that. That is normal vehicle stuff. What I am talking about it making sure that the parts of your van that had huge holes cut in them remain water tight.

Our van is not kept in a garage. It sits outside in all weather conditions. I noticed when installing the solar panels this spring that the sealant around the vent fan was looking gross. Mildew, dirt and some small cracks were starting to appear in the sealant. Last thing we need is for water to make its way into the van. Especially since the bed is literally right under the vent fan.

I also figured it was time to really seal up the attachments I bolted to the roof for the Moonshade. I coated the heck out of the screw heads with silicone caulking when I installed them but since I was going to do the vent fan, I might as well address these two hooks also.

I went down a rabbit hole of RV/Van/Camper roof sealants and the pros and cons of the various things out there. However, Dicor Lap Sealant was what consistently came up on any roof vent videos or blogs I found. It was fairly obvious that this is exactly what Wayfarer Vans used on my roof. The biggest debate appeared to be whether or not to remove the old sealant. Dicor’s own website says it is totally fine to apply over the old sealant after cleaning it and your van roof, so that is what I did.

The cleaning is a two-step process. First use good old fashioned hot water and soap to get rid of any dirt and grime that has built up.

Let the roof and sealant dry for a bit before moving on to the next cleaning step of using Mineral Spirts on the Dicor.

You do not need to douse the roof or sealant with the mineral spirits. A little bit goes a long way. Wet the rag and then use some elbow grease to clean the sealant. Keep lightly wetting the rag as you go around the fan. You’ll notice that some of the sealant is coming off on the rag, it’ll be a white residue. This is what you want, it is loosening up the sealant and giving it a final cleaning before applying the new sealant.

After cleaning with the mineral spirits give it about 15 minutes before moving on to the next step of applying new sealant.

the Dicor is self-leveling (oh yeah, make sure you are parked on a level surface when doing all this). Think of it as an amorphous liquid. It may look lumpy and uneven as you apply but over time it starts to level itself out. I would make a “perimeter” of sealant along the top and bottom of the section I was going over and then fill in the middle.

Any sealant you get on the roof should be cleaned up quickly with a rag and mineral spirits. I should have laid some cardboard down around the vent fan.

It may look lumpy but it will smooth out as the sealant levels itself. Trust me.

I’m far from a pro at this, and this was my first time so be gentle with me. I could visually see the sealant leveling out as I went around the vent.

After about two hours the Dicor looked much smoother and had a slightly rubbery texture. It takes 24 hours or so to fully cure. Make sure there is no rain in the forecast. I started cleaning the roof in the morning with temps in the low 60’s. But by the time I was ready to do the sealant it was in the upper 80’s and the roof was toasty hot. I waited until the sun went behind my house and it was cooler to be kneeling up there. I couldn’t find any specific warning about not doing the sealant in hot weather (it is a petroleum-based product) but I wanted to play it safe, and also not scorch myself kneeling on my roof.

I probably didn’t need to do this project just yet. Maybe could have waited until next year, but those few cracks I saw and a day off from work motivated me to give it a shot. I used one full tube and just a wee bit of a second. If I had been a bit more judicious with my application I could have probably gotten away with one tube.

Thanks for reading, let me know if you have any questions.

-Pete