Getting ready to reseal the seams in my roof

[gs1949]

The dry season has been interupted by a day of rain here on the Oregon Coast, the first real rain since before I started removing my ceiling. So I've been carefully inspecting the whole interior, looking for wet spots.. Only 3 out of the 4 windows I expected to see leaking actually leaked today. Recaulking windows is getting near the top of my to do list.

What I did not expect to see was small quantities of water seeping from a few rivet holes in most of the ten or so roof supports I looked closely at. So I think I'll start on the roof seams tomorrow because the rain appears to have stopped now.

I'm open to suggestions from people who have resealed their roof, but unless I come across a better idea, I will attack the old seam sealer with the same brush in my angle grinder that I used on the rust and seam sealer on the floor.

I have 2 tubes of Dynatron 570 left over from doing the seams in the floor. As far as I can tell 570 is the white version of 550. I don't think 2 tubes will be enough for the whole roof, but will be a good start, and give me a good idea of how many more tubes of Dynatron I'll need.

Thanks for reading. Comments and suggestions will be appreciated.

[farok]

My seam was leaking as well. I wire-wheeled the seam, primed it, added more rivets, and then sealed with Dicor self-leveling lap sealant. Check out my build thread for what worked for me (on a van cutaway short bus).

Chris

[EastCoastCB]

Originally Posted by gs1949

The dry season has been interupted by a day of rain here on the Oregon Coast, the first real rain since before I started removing my ceiling. So I've been carefully inspecting the whole interior, looking for wet spots.. Only 3 out of the 4 windows I expected to see leaking actually leaked today. Recaulking windows is getting near the top of my to do list.

What I did not expect to see was small quantities of water seeping from a few rivet holes in most of the ten or so roof supports I looked closely at. So I think I'll start on the roof seams tomorrow because the rain appears to have stopped now.

I'm open to suggestions from people who have resealed their roof, but unless I come across a better idea, I will attack the old seam sealer with the same brush in my angle grinder that I used on the rust and seam sealer on the floor.

I have 2 tubes of Dynatron 570 left over from doing the seams in the floor. As far as I can tell 570 is the white version of 550. I don't think 2 tubes will be enough for the whole roof, but will be a good start, and give me a good idea of how many more tubes of Dynatron I'll need.

Thanks for reading. Comments and suggestions will be appreciated.

sounds like a good plan to me.

[gs1949]

@farok, thanks for the suggestion. Is your roof flat? Mine's not so I don't think self-leveling any kind of caulk is what I need on my curved roof. I had no idea there were so many different caulks out there, but I'm learning.

I do have one tube of non-sag Dicor, but I bought that specifically for applying two 16 gauge patches to the holes where the emergency hatches currently rest. That project is upcoming soon. One more duck to get in the row first.

And I have a dozen tubes of Sikaflex 1A for recaulking the windows. Another big job to finish before the rainy season hits.

Most recently I bought 4 tubes Dynatron 570 Seam Sealer before I did the floor, planning on using any leftovers to start on the roof seams, and it took exactly 2 tubes to do the floor. I'm not sure how much it will take to do the roof seams. There are fewer seams in the roof than there are in the floor, but they look a little wider and have a larger bead of caulking, so it may take nore than 2 tubes for the roof.

@ECCB, thanks for the encouragement. I appreciate that.

[bus-bro]

Scrub and scuff your roof with a tri-sodium phosphate solution, rinse, and allow to dry. Apply Henry's Tropi-Cool paint per manufacturers recommendation, i.e. thick and quick.

Do things like use a small wire brush around the rivets and seams while you're doing your wash.

The stuff is a seamless silicon rubber roof on top of your bus. Your rivets and seams won't leak, hopefully, for at least ten years.

[musigenesis]

Originally Posted by gs1949

The dry season has been interupted by a day of rain here on the Oregon Coast, the first real rain since before I started removing my ceiling. So I've been carefully inspecting the whole interior, looking for wet spots.. Only 3 out of the 4 windows I expected to see leaking actually leaked today. Recaulking windows is getting near the top of my to do list.

What I did not expect to see was small quantities of water seeping from a few rivet holes in most of the ten or so roof supports I looked closely at. So I think I'll start on the roof seams tomorrow because the rain appears to have stopped now.

I'm open to suggestions from people who have resealed their roof, but unless I come across a better idea, I will attack the old seam sealer with the same brush in my angle grinder that I used on the rust and seam sealer on the floor.

I have 2 tubes of Dynatron 570 left over from doing the seams in the floor. As far as I can tell 570 is the white version of 550. I don't think 2 tubes will be enough for the whole roof, but will be a good start, and give me a good idea of how many more tubes of Dynatron I'll need.

Thanks for reading. Comments and suggestions will be appreciated.

My bus was originally leaking through many of the roof seams. A previous school system owner had attempted a fix by slopping something like Dycor sealant along the left side of each seam. In a number of places this stuff had hardened and shrunk and formed little holes that water was getting through.

It was still firmly attached to the roof, though, so I just ran my Dynatron-550 seams over the old sealant without bothering to remove it. I cleaned the seams thoroughly first, then scuffed them with sandpaper, masked off each side of the seam and smeared on the 'tron. They're kind of rough-looking since I didn't know about using mineral spirits, but I'm going to be putting tropicool on which will cover them up anyway. They are leak-free now.

Since my windows are black, I was actually hoping to find black Dynatron (not the '70s superhero) which I'm guessing at some point in the distant past was Dynatron-560? Doesn't seem to exist any more.

[farok]

My bus is a Collins, which has more of a flat profile than most. The self-leveling caulk doesn't run much as long as the roof is close to flat where applied. They do make the non-self leveling stuff, but I suspect the leveling stuff got more into the cracks, as I didn't actually pry up the seam. Now, it's covered with an elastomeric paint, and was leak free before that, so I've got high hopes that the issue is resolved for the foreseeable future (until the next coat of elastomeric paint).

Chris

[gs1949]

Thanks to everyone who posted their suggestions and experiences. I appreciate that. The clouds are pretty much gone already.

It looks like it's going to be a nice day today, and there's more sun in the 10 day forecast, with no significant chance of rain through the whole time period.

So in a little while I intend to get up on the roof with my angle grinder, attack a seam just to see what happens, and then take it from there.

[Biscuitsjam]

I didn't grind away the old caulk - I spent a day with a pack or razor blades and cut it away. Most of the old caulk was gone and the roof leaked a lot - the caulk that was left was mostly inside the seams and I needed the blades to get it out. I used Henry's clear caulk on all the seams (but not the individual rivets) and had only one leak when I finished. I hit the rivets near the leak when it dried out again, and I was leak-free. Eventually, I'm going to use the Tropicool paint, but I'm having no issues right now (except for a couple leaks I caused when I replaced the hatches).

[gs1949]

Thanks for relating your experience. My case is different. My bus does not leak a lot, just very, very slightly, but it appears to be leaking in quite a few places. The seam sealer that's there is solid and looks in good shape, but it's 25 years old, and so I assume it's just starting to leak. There's no rust, water stains or anything on the inside of the roof that would contradict that opinion.

So I intend to remove all the old seam sealer before replacing it with new Dynatron. What else I end up doing depends on how much paint comes off too. I have enough Rust-Oleum primer and paint to do every seam. I do want to put elastomeric paint on the roof, but there's so much to do before the rainy season that I probably won't get that done this year before the rainy starts.

[gs1949]

It wasn't as warm today as the forecast led me to believe, but I did make it up on the roof of the bus. First thing I figured out was that I was misremembering the way the roof seams are done, confusing them with the seams in the floor that I spent so much time with lately. There's no beads of seam sealer showing, and way more rivets than I remembered, over 100 per seam, and maybe 50 or 60 wherever there's a roof support with no seam.

So I am now thinking that the small quantities of water I saw oozing through some of the holes where the ceiling rivets used to be probably got in by oozing through the rivets just above them. And the most noticeable thing when looking at the rivets from above is the brown crud built up around them. It's a little dusty around here, and the deposits seem thicker than when I last looked a few weeks ago.

I intend to go clean some rows of rivets tomorrow so I can look for rust, but I am now thinking that this is a job for some kind of elastomeric coating rather than Dynatron like I've been thinking.

So I have been looking at elastomeric, starting with the Tropi-Cool some have mentioned above. It's certainly expensive, and so are the title, plates and insurance thing I want to do this month. But on the other hand the reviews for Tropi-Cool are impressive. I particularily like the part about being rainproof after 15 minutes of drying time, and the application temperature range is perfect for where I am, well the lower part of it. It never gets to 120 here.

I am curious about people's experiences applying Tropi-Cool, particularly the coverage. I need to decide if 3 gallons would be enough for just under 300 sq ft or whether I should just get a bucket.

Thanks for reading, comments and suggestions appreciated.

[Sleddgracer]

Originally Posted by gs1949

It wasn't as warm today as the forecast led me to believe, but I did make it up on the roof of the bus. First thing I figured out was that I was misremembering the way the roof seams are done, confusing them with the seams in the floor that I spent so much time with lately. There's no beads of seam sealer showing, and way more rivets than I remembered, over 100 per seam, and maybe 50 or 60 wherever there's a roof support with no seam.

So I am now thinking that the small quantities of water I saw oozing through some of the holes where the ceiling rivets used to be probably got in by oozing through the rivets just above them. And the most noticeable thing when looking at the rivets from above is the brown crud built up around them. It's a little dusty around here, and the deposits seem thicker than when I last looked a few weeks ago.

I intend to go clean some rows of rivets tomorrow so I can look for rust, but I am now thinking that this is a job for some kind of elastomeric coating rather than Dynatron like I've been thinking.

So I have been looking at elastomeric, starting with the Tropi-Cool some have mentioned above. It's certainly expensive, and so are the title, plates and insurance thing I want to do this month. But on the other hand the reviews for Tropi-Cool are impressive. I particularily like the part about being rainproof after 15 minutes of drying time, and the application temperature range is perfect for where I am, well the lower part of it. It never gets to 120 here.

I am curious about people's experiences applying Tropi-Cool, particularly the coverage. I need to decide if 3 gallons would be enough for just under 300 sq ft or whether I should just get a bucket.

Thanks for reading, comments and suggestions appreciated.

it should state coverage on the label of the paint can

[bubb, the real one]

Wash roof, rinse well, make sure the paint is in good shape , apply butyl RV roof tape, at 5 years mine still seals well

[gs1949]

@sleddgracer, the problem with that idea is that nobody stocks Tropicool around here, so I won't actually see the container until it's paid for and delivered, but I did finally find a figure on a Home Depot web page. They say it covers approximately 67 square feet per gallon. That means 3 gallons will not be enough and so there's a 5 gallon bucket in my future.

@bubb, thanks for your suggestions. I intend to was the roof today so I can see if there's any rust under the dust that's collected around rivets.

And what exactly did you do with the butyl roof tape? I have almost everything I need to patch the holes where I intend to remove the emergency hatches, including a roll of butyl tape, but I don't think there's anything else I need it for.

[bus-bro]

It took just under 3 gallons to do my 35 foot bus's roof. That was less than manufacturer's recommendation, which would of been 4 gal. Spread it as thick as I could with a roller with 1" nap.

[gs1949]

Mine is 35 foot too. I'll have to check again, but if I am remembering it right, the same webpage that told me to expect 67 sq ft per gallon said to use a 3/4 inch roller.

[edit] I couldn't find where they said to use a 3/4 inch roller, but I did find another page where they said to expect 67 sq ft per gallon but use a 1/2 inch roller. Personally I think the thicker the better, so I think I will follow your example with the thickness of the roller, but get 5 gallons just in case.

This stuff is not going to be easy to get around here, and if I do find it I'm sure it will be much more expensive than Home Depot. Amazon wants up to slightly more than $100 more than Home Depot. So I have gotten used to ordering things before I'm ready to use them.

[farok]

If you have time, use the leftovers to do more coats. I got 5 gallons of elastomeric, and on my shortie, it covered three times, and I still have 1-2 gallons left. When I have some more time, I may put another 1-2 coats on, as I'm sure it will help in the long run!

Chris

[gs1949]

Thanks, farok, do they say anything about recoating on the container? I see multiple encounters with low-hanging branches in my bus's future, and I want the roof coating thick.

Having some left over for repairs might be a good idea if I could keep it from setting too quickly. Probably would have to put it in a smaller container. How long have you been keeping yours?

[gs1949]

I was up on the roof of the bus for a while this afternoon, cleaned several seams and rows of rivets, and then spent some time scrubbing several places in between the rivets so I could get a more general idea what the state of the paint is. I used a scrub brush and a wire brush with a wooden handle. I didn't find any real rust spots, even under the crap that has built up around many rivets.

But I think I found quite a number of spots where the paint is just starting to break down. I don't know what else could be causing small spots where the paint is just a little rougher and darker than the paint around it. Upon taking my hand powered wire brush to quite a few of these spots, it seems they lose their paint just a little easier than the surrounded area where the paint is a little smoother, and slighter lighter in color. These are not big spots, most of them are quite small, less than a quarter inch across, and the biggest I found were maybe a half inch. But there's quite a few of them, maybe 1 or 2 per sq ft for much of the area I looked at.

It's pretty obvious I need to seal the roof with some kind of elastomeric coating, soon, before the rain starts. I've pretty much decided to use Tropi-Cool. But I'm not sure about what to do for prep. I don't think it's wise to ignore those little spots that seem to indicate an early stage of paint failure. On the other hand I hesitate to attack the roof with my angle grinder and the same brush I used on my rusty floor.

So I am trying to think of an approach that's somewhere in between those 2 extremes. I'm going to try to borrow a pressure washer tomorrow, and get more crud out of the way. That roof has probably never been cleaned properly, so that's my first step.

[solvo]

Originally Posted by bus-bro

It took just under 3 gallons to do my 35 foot bus's roof. That was less than manufacturer's recommendation, which would of been 4 gal. Spread it as thick as I could with a roller with 1" nap.

Get 5 gallons and apply 2 coats. I used a napless roller, but directions say 1/2 to 1”. Looks great and made a big difference in temp, plus seals.