It's time to vote on our 2017 photo contest! Vote for your favorite photos of the year here!

Advice for sealing rusty 1944 metal roof

Spring City, TN

It was "sealed" in 1984 before I bought the house. No one remembers what it was sealed with. It does NOT leak, but it is rusting.

I figure I'll be sanding off rust and rolling on a sealer coat of __________?

Any suggestions? Going to Lowes is just confusing. Fiber or non-fiber, silver or white, solvent or water clean-up, SCAQMD Compliant or not. Everyone else I know has asphalt shingle roofs so no experience there.

Durhamville, NY(Zone 5b)

I assume it is a galvanized metal roof. If that is the case what I'd explore painting it with zinc rich paint. You'll need to go to a real paint store to find it and I suspect that it's expensive.

Valley Of Adirondack, NY(Zone 4b)

Sorry I know this is a older post and not sure if help, ideas are still needed. I am a new member and reading a lot one here. I happened upon this so thought I would give some info just in case it was needed. My home is 1930 with a metal roof, it was so rusting when I bought the house. You can coat using what is called-Aluminum roof coating. it is a sticky tar like stuff that seals, can be used right over any rusty areas without any sanding needed. This Aluminum roof coating is silver like colored once it's applied which is done using a 4 to 6 inch wide paint brush, that is the best way to make sure you get a good even coating on you roof, where it should only have to be done using one coat. it is sold in 5 gallon buckets. a few other tips, make sure the bucket is stirred very well getting it stirred up deep bottom of the bucket fully before applying. this should be applied on hot days where at least a week after is dry and sunny, warm. Make sure no rusted or other areas of the roof have any holes. they would need to be repaired prior to using this coating. you will nee to know the square footage of your roof to know and get the amount of 5 gallon buckets you need.
coating a roof with aluminum roof coating is messy, hot, tiring, time consuming and more, however it will last for years. It really does work great even over badly rusted roof areas. this is also the most common roof coating used on mobile homes, campers and such not just older house roofs.
I hope this helps someone especially since this is an old post, Hopefully you did get your roof all repaired, sealed and good as new again.

Richmond, TX

I have used the coating that Willow_twig describes. It is a pain to apply and it takes a lot of it, but it does a good job and lasts for years and years. I was doing a barn roof and painted it on fairly efficiently with a small push-broom.

Valley Of Adirondack, NY(Zone 4b)

Thanks porkpal for adding more about using this coating. you added good to know info and important too. I had forgot the push broom being used too, I found that bristles which were thicker coated better than finer brush bristles the cheaper sort you would not normally want to use for any job. The paint brush I used on edges and the roof peak. just to make sure I had sealed/coated these areas good. Yes, too it does take a lot of coating too especially where areas are really rusty. It is a pain to apply, clean up after too. Though since it does a good job and how long it lasts I feel it is more cost efficient to do. Also where I live winter weather is pretty brutal, lots of ice storms, snow storms and very windy all year around. Spring is always very rainy, often fall can be too. So it is the best option for here unless you want to add an entire new metal roof. Shingles are not a good option here.
I also found that if you keep a plastic grocery bag or garbage bag kept tightly wrapped around the paint brush and covering the brush end of the broom fully too with the same you will be able to still use them the next day if you cannot finish the roof coating in one day. If you do wrap these make sure to store where it is shady, not an area that will get hot even if out of the sun. away from rain too.
A friend recently told me he used a paint roller, described the roller brush as plusher rougher type to apply this coating on his old camper roof. he thinks it was easier to use that and the coating went on really well, faster, though he would not recommend a bigger roof than a camper using such. It looked very well coated.

Missouri City, TX

I have used a Kool-Coat product with great success here in the Gulf Coast area. It forms a rubberized calling card thick coating.

Applied with a roller and long handle. Went on fast and has lasted for years. completely covered a 14x40 roof in less than 2 hours. It sealed all of the overlapping metal seams which was one of our objectives.

This was after the original roof had rusted so bad we had to replace it. Did not want a repeat of that.

Richmond, TX

Can it be used on an already rusty roof?

Missouri City, TX

I think it can, but all holes would need to be covered or it would drip through.

Post a Reply to this Thread

Please or sign up to post.