I bought this 5 gallon bucket of 100% silicone to fully coat all of the seams on my thin metal roof of an old 14 x 70 mobile home. The roof was rusted too.
First I swept the roof off, then took a leaf blower to it to get all the dust and dirt blown off, then I used a bottle of TSP and water to wash the roof. I let the roof fully dry for a few days of hot summer weather... Then I got back up on my roof and thickly coated every metal seam, thickly coated around everything sticking up through the roof, and thickly coated around the entire perimeter of the roof. That took up the whole 5 gallons, which I was glad I got them all....
So next, to try and make sure I was going to stop the insane leaks I have in the roof, I found a compatible product with silicone in it... it's like a white silicone paint. I got 5 gallons of that too and put it on. Days later, it rained, and most of the leaks were fixed, except for one. The worst one that I can't find the origin of.... But it was a lot better....but still... So then I went through eleven tubes of silicone caulk and put it on every screw and bolt, around the perimeter and more on everything sticking up through the roof... Then I added another coat of the silicone paint on the roof.... So far so good... No leaks... It's hard to say which one really stopped the leaks, but I have zero doubt that all of the silicone products I put up there is the reason why it's stopped leaking.
This product is very thick and went on great. I used a wide paint brush. I have no doubt whatsoever that this product really sealed it up good on the seams and everywhere I put it. It's also thick enough that I think this stuff is going to last years.
I would definitely buy this product again.

It's expensive but seems to be great so far.drys hard and will fill in exposed areas and gaps in your roof.don't let water get in your RV it will ruin it!

I read most of the reviews prior to starting my RV roof. I would recommend to follow their advice. I would also like to update it, with my opinion on what I did and/or did differently. Please note my roof is 25 years old and to my knowledge has never been coated. It is also not able to support any weight, as the plywood is "fragile" so all my work was done from a 10 ft. ladder, which was not ideal.

1) DAY #1 - Removed AC cover and all removable vent covers then I used diluted simple green, a scrub brush on a pole and a 1900 PSI power washing and repeated until satisfied. Once completely dry I draped plastic along the perimeter around, while taping off edges. It was only a 3 ft wide roll called "mulch film". Cheap, easy insurance. I could have probably just used tape along the edges of the roof, but I am a messy painter and this stuff requires some elbow grease to remove from unwanted surfaces. It was recommended on You Tube to drape full length plastic along all sides to divert the roof sludge to the ground, but the water used to clean the roof would have also released the tape. So I opted to wash RV thoroughly the following week...Use plastic sheeting to your liking.

DAY #2 - This is were all the reviewer's information came in handy. Opened a bucket, mixed well and began to trim roof areas with a brush. Bring the bucket or plenty with you as you are not really "painting" as much as you are "pasting" or "globbing" and you will use a good amount and sort of even it out with the paint brush. Wait 3-4 hours depending on weather and then roll the long stretches. let dry overnight. 1 coat done. I used a roller (nap) and roller tray on DAY #1 and was not happy with so I changed tactics on day #2. (explanation below) + it didn't really lay down "thick"

DAY #3 - Repeat Step 2 and now you have two coats which is definitely needed.

FINAL NOTES: I was apprehensive about the AMOUNT I needed, with most reviewers saying they didn't need much at all. I DISAGREE. If you "brush" and "roll" like traditional paint then you will not use much. But I dont think this correct thickness. I bought 2 gallons for my 24 ft. RV and got nervous and ordered a 3rd the day before I started. I used all of it. I poured and spread my 2nd coat, which I think is the correct thickness. Think of it more as like driveway sealer (granted you have sealed a driveway), rather than paint. Pour a half gallon and spread, repeat. If I could do it again I would follow the Manufacture's advice and poured and spread both coats and used 4 gallons for my RV.

NAP ROLLER was a bad idea. 3/4 brand new "mid range" nap roller purchased and this RV coating just pulls all the nap off the roller and into your finish. Day 2 I bought a 3/4 "foam roller" as mentioned and it was much better. I think you could use any thickness foam roller and just use it to level out the coating. Used Rollers were power washed and placed in zip lock bags to try and save. It didn't work. You will need a new brushes and rollers the next day.

Do not go over semi dried areas because it will peel up and flakes will get on your roller or brush and into your finish. If a covered area looks thin in a spot, leave it alone if has been more than a minute. It probably has already set up and will "peel" off onto roller/brush and peel off that spot.

Opened buckets that are resealed will still "skim coat" on the surface overnight. DO NOT mix this. Scrape along the edge to release the firmer skim coating and remove before re-mixing bucket.

I have no idea if my prep work and application are 100% sufficient. So how long will it last? I just am re iterating some of the important things other mentioned and adding my own experiences to help others. Good luck!

Great Product

Day 1.
Clean the roof and the the rest of the camper. I didn't use a pressure washer in fear of tearing the roof, so bleach and dawn dish soap and a stiff brush.
Acetone the roof A MUST. To remove any left over dirt or old roof conditioner. A quart is more than enough for an average size fifth wheel.
Day 2.
Etrnabond tape and new lap sealant. It needs to setup so done for the day.
Day 3.
Taping off gutter to keep from getting sealant on it.
Cutting in around the air and vents and along the edge. My 5th wheel has a radius roof edge. Must dry completely before doing any more. Done for the day.
Day 4.
Coating the entire roof. Let dry and done for the day.
Day 5.
Second coat. Let dry and cure. done for the day.
Day 6.
Touch ups on what you missed. Install roof vent covers and a final look at finished job.
Conclusion.
Happy with the job, time will tell about durability. You need to make sure you prep the roof . Clean. Acetone. Is a must.

This product is silicone it dries and feels like silicone. The roof is cooler and water proof. Will not peal off it's stays stuck so your committed. Etrnabond and lap sealant will not stick to the roof anymore so make sure your prep is done before you coat with this product. Also it will skin over if you leave it to the air too long so do small areas at a time or keep mixing it or pull off the skin do not mix it in or you will get lumps.

I recommend it.