The roof sure does accumulate a lot of dirt, especially this time of year with all the pollen. Just make sure that you are careful putting the 303 on. The roof will get very slippery. What I do is go to the Dollar Store. They sell a sponge mop which is what I use to apply the 303. If it lasts for the entire roof, I will save it for next time. If not, I toss it. It is $1 well spent. What's departure date?
ps- If your son wants to take a ride north, my roof could use a washing too(LOL!!).
Tom and Margaret
2014 Berkshire 390bh-60