Rust on steel i beam

[john dj]

Hi my house was built 12 years ago, l noticed rust on the supporting steel i-beams underneath my house, l have some photos.
How serious do you think the rust is, is it just surface rust or could it be more serious, Does the rust need to be removed, what is the process and how
expensive would it be , thanks

 

[mrrusty]

This is a UK forum so your situation is very uncommon here. However, to me that looks like surface rust which will stabilise and prob not much to worry about, unless you are very near the coast and getting salt spray, in which case I would expect corrosion to continue.

 

[john dj]

thanks so you think its just surface rust. l am 2 km from the coast, should l get the rust removed or treat it to stop corrosion, would that be expensive

 

[mrrusty]

Personally it wouldn't be bothering me. It would take a very, very long time in a dry place under your building to corrode to a point where there would be any risk at all. However, if it bothers you, you could paint on an inhibitor like https://www.owatroldirect.co.uk/product/owatrol-oil/ - you can probably get something similar locally. I wouldn't be paying anyone to treat it... You can just rub this oil on with a rag - it doesn't take much - a little goes a long way.

 

[^woody^]

It should be protected, especially so close to the coast.

Consider a wax spray coating as used under cars. This should be quick, easy and cheap.

 

[john dj]

thanks its only 12 years old so do you think because of how thick the steel is it would probably take decades to become a serious problem. if l were to apply a coating or spray should l sand the rust off first

 

[^woody^]

Steel can corrode quite quickly in salt air. I don't think it's incremental year by year either but gets faster and faster each year as the rust gets worse. As for how soon that steel would become structural issue, you'll need a smart college kid to work that out.

Generally for any treatment, loose surface rust needs to be removed.

I've had good results with products from Jenolite. It may be the Rust Shield product you want, which is a wax which treats and stops the rust and coats the steel with a rough, hard wearing but flexible barrier.