Whether your roof has been painted previously or not powerwash just before you start painting.
Painting old tin roof.
Water resistant metal roofing paint for example can be of great value if you live in a rainy area.
Generally a tin roof is referring to one of two things.
Try to achieve a slightly abraded texturized finish as this helps your new paint bond with the roof finish.
You ll also need to purchase a primer designed for metal roofs.
However if the old roof already has a coat of paint on it you ll need to prepare the surface for the fresh coat of paint.
It is very rare to find an actual tin roof.
For pricing and availability.
Another mistake is to forget or ignore using a sealant before the application of the metal paint.
The term tin is a misnomer in this situation.
If you want to paint a new metal roof though you can prepare it by washing with a weak acid such as diluted vinegar to remove oils and residue first.
Just before painting wash the roof with a power washer at a pressure of 2 500 pounds per square inch whether it is a new or an old one that requires re painting.
This step removes mildew dirt and any loose bits of old paint that can cause adhesion problems.
Make sure to use a putty knife to scrape and scratch away all loose pealing paint.
Not using a sealant.
Although it isn t recommended to use a metal implement to scrape the roof it was the only way to remove the loose rust and old paint.
This is why when you are considering painting your metal roofing it makes sense to go for specific paints for the metal roof.
If you re not sure what kind of roof you have ask a professional roofer to inspect it before you paint it.
Terne tin is a little trickier to determine.
The first incarnation of the tin roof was a sheet of steel with a tin coating on the surface to prevent oxidization.
If you have a terne metal roof like this one then it has probably been repainted several times over the years.
Black jack silver seal 300 4 75 gallon aluminum reflective roof coating 3 year limited warranty item 12035.
Black jack elasto kool 1000 5 gallon elastomeric reflective roof coating 10 year limited warranty item 139941.
Be extremely careful not to pierce the metal when scraping.