Help from you coastal guys.

I have a galvalume roof on a gulf beachfront house. It has 3 areas of moderate to severe rust that appears to have started on the drip and is spreading to the panel. The rest of the roof is in very good condition. 10 years old.

What is my best treatment to preserve the roof as long as possible? I thought about wire brushing and spraying with an aluminum polyurea, but it's bit of a tough operation for such small areas. If there is something from a paint store that will work well, I think I prefer that option.>>>

http://www.gemplers.com/tech/mremovefaq.htm

Use a rust converter (it chemically changes rust to a primer) and an oil base or epoxy paint on the affected areas. There are several brands, I don't know which is best.

May look a little conspicuous, but it's coming off relatively soon anyway, right?

On the sections I photographed above, I used ospho and spray galvanizing compound. It did not work well. In the one area I could not photograph, I cut out the panel with a grinder, (about 18" wide x 12" high) inserted a flat galvalume pan, stitched with screws, caulked screws and cut edges with geocel. This area is fine. It doesn't look good because I'm missing 12" of a rib, but it's functional and on the side of the house. The only person that sees it is my neighbor if he looks out the bedroom window. Other sections I wire brushed and caulked with geocel with mixed results.

Even with the ospho and galv, my corner details in the photographs are deteriorating very quickly and there is now some significant rust-thru.

I am hoping to milk this roof for at least another 6 years until my last child graduates. I need a roofer with the skills to repair/replace these individual details. I did all the tough detail work on my shop when we put metal on it, but I don't have the tools, time or real skills to do this project in the limited time available when I visit. When it is time to re-roof it, I'm thinking I will go with a Sarnafil Rib system, 60 mil fleeceback fully adhered.

As my family grows the house is quickly becoming too small and I hope to keep the roof maintained until I can do a major remodel, and raise the house by 1 additional level, making it a 2.5 story house instead of a 1.5 I'm having my doubts that this plan will work, but financially, I desperately hate the idea of roofing it once in between. It's only 12 years old right now.

floridaroofer,

You wouldn't happen to be on the panhandle would you?

The first thing you have to do is get rid of the rust if you're not going to replace the panel, then there are options after that. Being in the rust business before I know that there are great products affordable to the consumer that literally eat rust right off of metal. I completely cleaned a jet ski lift by the saltwater w/o any wire brush whatsoever. Obviously if the metal is rusted so bad that the integrity of the panel is weakened this won't work. If you have surface rust which is what is looks like, then just use one of these products first: Chemprime or Ospho, both have a primer built in. You can usually find one of them at Ace Hardware. It may take several sprays, but it will eventually come off. Now that you've taken care of the rust problem lets move on to what you have to do to protect your roof now. There is metal paint, but it will require a lot of prep work and because most paints are not long term and sustainable like a ceramic paint is, then you will eventually have to recoat it because it is either fading or chipping. If you want to coat it, Rhino Shield makes a top quality product. There are also other options like roof coatings. Coating vary wildly with the ingredients each manufacturer chooses to use for their top coat. This is usually what makes the coating vary in price so much. The pigments break down with UV, heat, expansion and contraction, and salt and eventually dry the paint or coating out. There are quality coatings, but make sure you get a good one. I think Seal-O-Flex makes a great product, but I would also consider their copycat Hydro-Stop or Topps. My first look would be at the Rhino Shield Ceramic Coating though. They are former painting contractors who went to 3M and got them to design a specific product that would outlast anything on the market, or so their story goes. Being they are from my home town and see how fast their business is growing, I tend to believe them. Remember, there is always replacing the panel(s) as an idea first if they really need it. If you decide to reroof definitely go with a PAC CLAD Aluminum. It blows away galvanized for coastal areas. Good luck and make sure you choose a reputable contractor should you hire one.

I'd suggest clear brush grade geocel for a repair.It locks the rust and it's not much noticable.For the whole roof liquid rubber may be the solution.there are some manufacturers that claim their products can be sprayed directly over the rust.Perma dri is one of them.>>>

From the appearance of your pix, I'd recommend ossiphorous ( I know the spelling is not correct but if you ask at the paint store [Ace] they should know what you want). Spray apply liquid product (wear a mask ) let dry and seal/paint. We used ossi phorous repairing roof metals prior to painting that had similar surface rust and it completely stops rust from returning. Naval shipyards use it to maintain the fleet, municipal water districts use it to refurbish pumps, etc. We used to purchase it from paint stores, ( Ace might be able to order it?). It's fairly pricey but goes a long way and it gets all the 'fingers' of rust out of the metal. Converts the rust back to iron, where wire brushing only works on the surface, this will eliminate the rust completely! Wear a mask, it stinks like all hell...

SC >>>

Jeff,

The only place we use any galv/g-al metals are our insulation discs. So, for me to accurately say g-90 or galvalume is tough. To me, it all has the same textural finish and appears to g-al.

Here are some pics of the rust and eave detail. Morning sun is behind the house so good pics are tough.

[IMG]http://inlinethumb48.webshots.com/44847/2999438500049336972S600x600Q85.jpg[/IMG]

[IMG]http://inlinethumb17.webshots.com/44688/2896272240049336972S600x600Q85.jpg[/IMG]

[IMG]http://inlinethumb18.webshots.com/24017/2211028840049336972S600x600Q85.jpg[/IMG]

There is one additional section on the side of the house, I cannot get a good pic of it. It is the worst rust section.

I first noticed rust in May. I have been surprised at the rate of spread. Thanks for the info in the e-mail.>>>

Ohhh. Tell me about the eave detail. Are you sure it's not G90 Galv. drip and Galvalume panels? Is the panel bent under to cleat into the drip edge? Is there possible a channel that the panel slides into? Was an advesive or sealant caulk used at the eave? Is the facia board or decking pressure treated with ACQ?>>>

I don't know if this helps any, as the pic doesn't directly show the rust, but if the pic shows you anything that means anything, here it is. All rust is contained to the drip edge, or just starting up onto the panel edge.

[IMG]http://inlinethumb02.webshots.com/13889/2245086170049336972S600x600Q85.jpg[/IMG] >>>

From what you've described (distance, eave height & slope) your exposure to ocean spray isn't as bad as what first came to mind. Around here we've got small, almost flat roofs that are 10 feet from the water with 8' eaves. Most of the salt water spray that makes it to your roof is probably washed off every time it rains and it probably take a good storm to get the salt spray on your roof to begin with.

Have you given any thought to just replacing the panels that are rusting?

If that is not an option, then cleaning the metal, chemically converting the rust to magnetite, sealing and painting ought to do the trick.

>>>

Mike H.

Why don't you contact Inland on their web site and get them to ship you some samples. They have small cans of product they use for samples (1/2 pint) A couple of them would probably cover what is rusted and you could see how it works. May even turn out to be another selling tool for your own company.

I've used it on metal roofs, inside a water cistern, fixed a rusty horse trough, painted it on stair treads and coated with granules to create a non-slip finish.>>>

Jeff,

Never measured, but it is beach-front. Maybe 100 yards to the high tide mark. ??? 70 feet from the dune line.

Pitch, I'd say is 8 or 10/12 Eave height, about 23-25 feet

The rust is currently contained to 3 small areas. 2 at each beach side corner, under the ridge cap, and 1 has spread to the downturn piece of the ridgecap.

The other is about 1.5 panels wide and is spreading to the panel.

Some loose scale appears evident, but I don't think it has yet rusted through.>>>

A couple of quick questions Mike:

1. How far from the water are you? 2. What is the eve height? 3. What is the pitch on the roof?

Can you better describe the size and depth of the rust? Is it rusted through? Is it surface rust? Are you getting flaking?

Without more info, I would have to agree with Vaa. A good fibered aluminum paint will preserve it for a while. Of course, it won't be as pretty as a new Galvalume roof. (I try to avoid selling unpainted metal because of the rust.)>>>

I need something that is readily available. There are no big supply sources for commercial products near me. Some "mobile home coating" may just be only thing available at Ace Hardware. Spread plenty of it myself over the years Mike, and that's not a half bad idea. I'm just hoping I can get something that will last a lot longer.

Anyone know what the expected life of a galvalume roof is directly on the coast?>>>

Jed: We used the brush grade RC2200 on the seams on a 60 square standing seam galvanized metal roof that was starting to show signs of rust. We then rolled the flat panels with RC2000 in white. Did two coats on both. We didn't spray due to the building being a dealership for heavy duty trucks and with a lot of 24/7 traffic around.>>>