External rendering on marine ply

[abenn]

My daughter's 1990's brick house has an external panel of rendered ply as a feature spanning between the bottom of the upstairs and the top of the downstairs window at the front of the house. It curves outwards slightly at the bottom.

The ply (not marine ply, I think) is delaminating and decaying at the bottom edge to the extent that I think the whole panel needs replacing.

When I do the replacement I plan to use marine ply, but I'm wondering about what render to use: Should I use sand/cement with a waterproofer in it, and then paint it with masonry paint, or is there a more-modern wholly synthetic type of thick textured paint which would do as good or better job?

 

[abenn]

Any ideas please?

... or is ply the wrong material to be using in the first place?

 

[JohnD]

can't see the point in rendering it if it's painted

You could use marine ply (pref seal the edges too) and a textured paint. I think you'd have to consult the paint manufacturers to see what primer would be required and if you can use textured masonry paint (not something I've done). if you use a non-textured paint I think will just look like painted ply.

Alternatively you could use e.g. shiplap with a water-repellent stain unless you have to match the houses next door, though this will need treatment every few years which is tiresome if you need to arrange ladders, scaffolds etc. Masonry paint can last 15 years.

 

[Micilin]

Any ideas please?

... or is ply the wrong material to be using in the first place?

Yu could use ply, building paper and eml or rib lath then render. Fair bit of work, but easier to get the materials


Or you could use Superlux , or Glasroc board. These can then be coated with Troweltex , HI Build or some other external textured finish. These could also be applied to the render system above

 

[JohnD]

But this is a Gypsum board, surely it won't stand up to external use?

I like your idea of using a board though, maybe some kind of cement board that will stand up to outside use? It could even have insulation behind it.

 

[abenn]

Thanks for the replies. I was perhaps using the term "render" in too wide a sense. I don't particularly want to use sand/cement render, but someone had told me it would be a better job than textured paint which is on at the moment

My instinct tells me that a modern material will be best, and I like the sound of high-build paint, as mention by Micilin. What's on at the moment sounds something like that, so I'll do a Google search on Troweltex and Hi Build.

JohnD, I don't think cement board will be suitable because it needs to be curved at the bottom edge -- unless that bit were to be built-up in render before coating the whole thing.

 

[JohnD]

is the curve to throw water off?

 

[abenn]

is the curve to throw water off?

Yes, it keeps if off the downstairs windows. But it's also a nice feature -- I think it wouldn't look right if it were straight