Our house is rusting away!

[davejold]

Hi, I'm new to this site.
Our house is on the coast and is block/rendered built (30 years old) and coated with white masonry paint. The sea salt has caused the galvanised steel render beads to rust and rot at damp course and first floor level. The rust running down the exterior white paint is very unsightly. Can anyone suggest a solution? Appreciate any help, Dave

 

[shaggy]

You could chisel all the bead out and replace with stainless steel, or paint the house a brown/orange colour.

 

[davejold]

Thanks for quick reply shaggy, I did think of painting the house rust colour! No seriously, as you say taking out the beading, I did think of using an angle grinder as there is approx 100 metre in total to replace with stainless or plastic and re-render about 6" above the the new beading, but this would be a very time consuming job and I am worried that the match with the new render to the old would show badly. And would it be okay to render over masonry paint? Or is there an easier quicker way? Regards, Dave.

 

[shaggy]

I've never used the plastic bead so can't comment on it. I don't see why you would be rendering over the masonry paint though? I would chop it back to the blockwork, fix the new bead and render up to the old. It may blend better if you use a chisel as it will leave a ragged edge which may blend better. It's a lot of work and the sort of job you should set yourself a daily target.

 

[masona]

You need something like Comma Stop Rust and paint it over.

Check the details on the instruction for salt protection.
They use this on our jetty and crude ship.

Some Hammerite paint can also paint over rust.

 

[davejold]

Thanks for your comments shaggy, what you say makes sense. Perhaps this will be the only permanent way, I just don't look foreword to the job. I have tried 3 coats of Hammerite masona but the rust still comes through after about 2 months. I wonder if Comma Stop Rust will last longer. Dave

 

[masona]

I wonder if Comma Stop Rust will last longer.

Well they paint the ship with it and it's in the salt sea water all the time ! Give the manufacter helpline a ring to see what they say.......

 

[pieman]

It may be that if the bead is still fixed in the render, when you paint it, it is not possible to cover all the surfaces of the bead, as it is embedded. The rust coming through might be beginning at a point you weren't able to paint, but still gets saturated with salt water.

Stainless steel will not necessarily be totally resistant to salt, depending on the quality of the stainless.
I've never used plastic, but it may well be more resistant to corrosion.
There may be types of plastic that do degrade in a salty environment , but I suppose they are unlikely to cause staining, and it would be pretty daft to make render beads out of them!

Would an aesthetically pleasing cover piece (timber, plastic?) be an option?

I think it would also be important to try and work out why the beads have rusted at two places in particular - what is happening differently here?

 

[doc]

move house, go inland a few miles

 

[shaggy]

You could move the house doc, but it's a big job. The house has to be jacked up and rested on steel beams with wheeled dollies that are towed. Here is an example. You can read the full story HERE

I've looked on the Expamet site and they use type 302 stainless steel which is used for marine purposes. It's not as corrosion resistant as 316 but it's part of the 18-8 group i.e. 18%Cr-8%Ni. which is a commonly used stainless.

 

[masterbuilder]

i've seen some nightmares with rusting beads and that on corners and reveals over a whole house.
i don't know why people use beads in the first place, you just temp fix a wooden straight edge or batten where needed on corners and reveals and remove it when the gears almost gone off then float up and sponge off.
this is an old technique after all, been done for thousands of years before beads were invented.
If i were u mate i would get rid of all the rusting beads now by cutting them out and making good the corners as needed.

 

[davejold]

I'm glad to see more info on my problem. Yes pieman the rusted beads are partly coated with render and the rust is coming through, this why coating with rust proof primers don't seem to work. The beads are rusting all around the house, not in one particular area.
I don't fancy moving the house doc, too heavy to lift, with my back!
Interested to read your comment masterbuilder, I have used this method rendering up to a batten in the past, as you say, nothing to rust or rot. I think this sounds the best solution, what I can't decide is whether to butt the new render up to the old render or slightly overlap, I'm not sure which would blend in best.

 

[masterbuilder]

what you need to do is fix a batten where u want to cut down in a plumb line and cut with a small grinder and diamond blade.
when u re-render line up corner batten with existing render and with 2 coats (1 scratch coat) finish flush with the existing render, float and sponge it carefully and if the join does show, at least it should be plumb or straight

 

[masona]

Might be an idea to planed the timber sloping downward so the rendering act as a drip ????

 

[davejold]

Thanks masona, good point, hadn't thought of it, yes I'll do that. I feel sure now that this is the best method.
I previously failed to mention that the vertical corners don't have any beading, so these are okay, the rust problem is only on the horizontal render beads at damp course and first floor level. Regards, Dave.