Replies

1. 
   kkearney | Feb 22, 2001 05:36am | #1

   *
   Log,

   I think I would trim the ends with a nibbler. The silicone may be causing some of the rusting if it was acid cure type. Scrub the roof with soap and water to remove all the little steel particles that are also rusting. Try a rust converter like ChemPrime on the pieces that you trim off to see what color they turn. If they don't turn too dark that may work on the roof rust. Never seen painted galvalume. I suspect the roof needs to be changed out or flip it if just a gable.

   KK

1. 
   Luka_ | Feb 22, 2001 06:36am | #2

   *The local boat shops here carry a product that changes the chemical composition of rust from iron oxide to iron phosphate. It goes by many names, but the one that I've used and liked, was "Rust-Pho"On the bottle, they guarantee that it will never rust again.Remove all the silicone, clean it all up again, and flood all the affected areas with this stuff several times. Letting it cure between times. Seriously, flood it. You want to get back up into every place where rust could possibly ever start in the future.

1. 
   Art_B | Feb 22, 2001 03:09pm | #3

   *There are also the heavily loaded zinc paint that work well - one brand is Galvicon, must be the type that is electrically conductive to work well, plain zinc coloring does not work.Used some as long ago as 1974 and still holding up. Even used it successfully to electrically and physically seal buried conduit threads at a Navy base in HI (volcanic soil there very corrosive).

1. 
   JohnD_ | Feb 22, 2001 08:00pm | #4

   *Log Man, you have got problems. The attempted repair has really gotten things into a corner. Before I go any further, let me get on my soapbox:b NEVER USE SILICONES AS SEALANTS, ESPECIALLY FOR OUTDOOR WORK!!!Luka is right, but he fails to tell you how hard it will be getting every last trace of silicone off. You will really have to scrape, use solvents, and scrape some more. If silicones are there, water will bead up, like on an oiled plate. You have to keep working until the affected area does not have water beading. And, in spite of what some people might say, there are no magic potions to remove old silicone.If you don'tdo a complete job, any future work will not survive. Nothing sticks to silicones.Once you are down to clean metal and firm rust, you can start to do something. That conversion stuff Luka describes really works. The non-toxic versions contain a derivitive of tannic acid that reacts with the rust to form a stable compound, and it tightly adheres to steel. It has pretty good life, but you are best off coating it because it looks pretty ugly. Lifetimes are improved.b Don't use the acidic (phosphoric acid, usually) rust converters. They are more trouble than they are worth, and don't work any better.If you have small holes to seal, a high-end butyl caulk will work really well. Another choice are the urethane-based adhesive/caulks. Larger holes need to be patched with metal.

1. 
   Phat_Bastard | Feb 23, 2001 01:37am | #5

   *Log Man,Not good, not good at all. How many sq. ? Snap lock seams or real rolled seams. I'd tell your roof guy to eat it and start over the right way and if he balks, have your business attorney tell him again.Reputations are our most valuable asset as builders. Fight for your client and make it right. Take the whole thing off. BeWell, PB

2. 
   Bucksnort_Billy | Feb 23, 2001 01:59am | #6

   *Log Man, Galvalume should not be rusting after a year, maybe 50. Get in touch with them, then the installer. It's good stuff, never had a problem with it. BB

3. 
   Scott_Chadbourne | Mar 02, 2001 06:27am | #7

   *I would almost bet that they either ground or cut the metal on the the face side rather than flipping the metal over. The hot sparks will land on metal and burn through the paint leaving a rust spot just as though it were welding splatter. If you think about it a minute, all metal is end cut or sheared as it is roll formed.....Otherwise it would be the length of the entire roll of coil stock. Almost all distributors will cut metal to the nearest inch for the customer. To rip the metal I use a pole barn nail and score along a rib several times. Bend the metal a couple of times and it will snap just like glass. Be sure to wear gloves as the edge will be sharp. 12-14ft lengths are the most I can snap without leaving ripples in the snapped side. This will only work on a grade E or harder metal. 29ga is easier than 26ga to break.

4. 
   Ed_Gregg | Mar 02, 2001 02:13pm | #8

   *It is extremely rare that someone would have to tear a metal roof from a building. I was part of the original Galvalume product team at Bethlehem Steel where it was developed in the early 70's. During the first few years that we marketed the product, we had some coating failures for a number of reasons. In each case, we contracted with a reputable commercial roof painting contractor to clean the entire roof and repaint it - if the roof was raw Galvalume, then we matched the metal color. Of course the spangle did not show after the raw Galvalume was painted. The only time we recommeded roof replacement was if the roof and/or the structural supports were not sufficient or if the roof was corroding underneath - typically from a chicken or hog shed which was not an approved application. If you want technical information, contact the regional Bethlehem Steel Sales office for a service engineer to have a look. Other steel companies are now licensed to make Galvalume, but it may difficult to trace the manufacturer. Also, you will want to contact the company that provided the Galvalume - not the contractor, but the firm who purchased the Galvalume from the steel manufacturer. They have a vested interest in the roof's performance and they should be aware of the shoddy work by the installation contractor. Good luck!

2. 
   Log_Man | Mar 02, 2001 02:13pm | #9

   *
   A client of mine recently had a standing seam metal roof installed on his home within the last year. The manufactures of this roof stated in the installation instructions that under no circumstances should any portion of the roof be cut or trimmed with an abrasive wheel or grinder. This would melt the galva-lume (spelling?) and cause the roof to rust. Well, they did it that way and it is rusting. Short of tearing off the roof and starting over, does anyone have any suggestions on how to clean up rusted areas and prevent future rusting? The worst spots are at the bottoms of the standing seams (at the eaves). The installers did come back out and attempt to fix this part of the problem by sanding off the rust, repainting and filling the ends of the standing seams with silicone. The silicone has started to come off and the rust is working through the new paint. My client has had repeated discussions with the installers to no avail. Can anyone offer any suggestions on a fix for this roof? Thanks