Corrigated roof tin

37chief · Jul 30, 2018

I have enough roof tin to cover an old shed. The tin was made in the US about 60 years ago. Good thick material. It has weathered from 60 years in the open. The under side still has the galvanized coating, but the top has rusted, most of the galvanized is gone. I plan on putting the good side up, hoping to get a few more years out of it. I wouldlike to paint it white.I am thinking exterior latex any thoughts? Stan

FBH44 · Jul 30, 2018

I have done that, except for the paint. It has lasted 30+ years, looks just fine. The galvanizing is meant to be exposed. I'd think chunks of the paint would flake off, and after a few years it'd be REALLY ugly.

JD Farmer · Jul 30, 2018

I'd put it on the same way it was, rusty side up and brush (broom) a good coat of silver roof paint right over the rust. I have done it to several buildings and it will last for many years. Got one I done 5 years ago that had the edges rusted off, and it still looks the same.
Gotta get the kind with the tar in it...no cheap box store stuff.

DoubleO7 · Jul 30, 2018

There might be some sort of etching liquid that will work when wanting to paint galvanized roofing.
But I doubt it lasts.
Are you old enough to remember galvanized steel roof gutters after they were painted?
I do and they all were peeling to some extent.

If you install zinc up you will have "purlin stripes".
And what you gonna do with the existing holes?

JMOR · Jul 30, 2018

I installed some 'newer' corrigated tin on a barn about 1986 and my helper wanted every other sheet flipped (opposite side up to the prior sheet). I don't know why or 'who a thought it', but clearly the galvanize was better on one side than the other, as now we have a barn with every other sheet rusty! Pick it out easily in aerial photos though,

kcm.MN · Jul 30, 2018

(quoted from post at 16:10:12 07/30/18)
And what you gonna do with the existing holes?

I've used aluminum HVAC tape with great success. We live so far in the country that I don't worry about painting it, so couldn't say if or how well it might hold paint.

As for the panels, I would install good side up. The rust from bad side will just hold moisture and debris/dirt better, which would likely decrease overall life of the roofing.

kcm.MN · Jul 30, 2018

Forgot to mention - When using that tape over these holes, I clean each hole thoroughly with dampened rag (with water; no soap) and dry, then tape. Also have to use smooth, waxy backer paper to rub the tape into the metal for best seal.

dpendzic · Jul 30, 2018

why not paint the rusty side with cold galvanizing compound? we used that a lot on rusted guide rail and rusted bolts

tomNE · Jul 30, 2018

DO NOT USE LATEX! old fashion oil based barn paint is the only way to paint it. I always spray it on. 1 coat is good for 8-10 yrs. 2 coats last forever BUT they have to be sprayed on about one year apart as the paint takes quite some time to dry. I don't clean or anything; just get the 5gal pails from menards or home depot and some paint thinner and spray away!

Stephen Newell · Jul 30, 2018

Exterior latex paint will adhere to galvanized metal. I think I would also paint the rusted side too.

led · Jul 30, 2018

I agree. Silver Dollar sold at Big R.
Led

george md · Jul 30, 2018

Use asphalt based aluminum paint , it is made for metal roofs and sides of metal
buildings and grain bins .
I would spray the under side before installation so the condensation rust it
from the the underside. Most metal roofs fail from the bottom not the top.

george

olgentdc · Jul 30, 2018

use the shiney side up ,. done it many times and was pleased with results. Galvanizing is not as good as it was during and after W W 2 and got poorer with each decade. or maybe the atmosphere became more toxic ? My Dad would be 104 and he attested and stated this in his old age ,1940 , he put on a new barn roof at granpas ,
1947 New barn roof at Dads new Farm
1954 then New tin on the machine shed
1965 another brand new barn
1971 new Hog finishing Building . All Buildings Rusted within 5 yrs of one another . granpa's 1940 roof still glistened in 1965.The Hog finishing building rusted last but when it did it was so bad i feared to walk on it ,

Kansasredneck · Jul 30, 2018

If you can get some, add zinc powder to your paint.

cannonball · Jul 31, 2018

If you look at the sheets that is correct way to make the tin fit one with edge looking up and next one down and third looking same as first under the 2nd one...and then one up again..this is for the 2 ft tin

Texasmark1 · Jul 31, 2018

I used mobile home roof coating with a brush made for the purpose: Medium bristle 2" long thereabouts, 3 x 6" thereabouts, hole to accept handle, regular roofing brush carried by Home Depot which had the 5 gal buckets of coating. Worked great. Priced right...spreads out real good for a lot of sq. ft. per gallon.

Corrigated roof tin

37chief

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FBH44

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JD Farmer

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DoubleO7

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JMOR

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kcm.MN

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kcm.MN

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dpendzic

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tomNE

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Stephen Newell

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led

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george md

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olgentdc

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Kansasredneck

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cannonball

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Texasmark1

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