External rendering - what's in it?

16 Jul 2006
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United Kingdom
New pvc windows installed causing some damage to the smooth white masonry painted external rendering. Fitters have patched it up with same mix they used to repoint odd gaps in mortar around other windows. The patched render looks pretty rough compared to the original (painted) areas.

Is the stuff used for render just brick mortar? Or should they have applied something else to get a reasonably smooth texture to match existing (which isn't a textured or Tyrolean type finish).

We don't want to just paint over the patches if it will still look bad afterwards.

Any advice welcome. Thanks.
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plastering sand.
waterproofer and air entrainer (plasterciser).
a damn good mixing, and a fair bit of skill.
Thanks noseall.

So they have used the wrong stuff to "match existing", as I feared. I'll have a word.... :rolleyes:

Helpful info from this site as always. Thanks again.
Plastering sand is actually coarser than building sand so it's not so much the mix but the application.

Anyway, I've never seen window fitters patch anything properly yet so I don't like your chances.
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Usually best to take the revel off and redo it properly, if them window-boys have just knocked the render off to get windows in and re-rendered nine times out of ten if you tap the revels with a hammer (Gently) they will sound hollow,(Boxy) this is what happens when you knock render off with a bolster and a lump hammer. the best way to take patches of render off is grind it first and then knock it off. I have known window-fitters to put dash back on revels with SILICON!!!!!!!!!!! I'm not kiddin. So check em out. ;) Flat render scratch coat 4 sand 1 cement w/proofer float coat 5 sand 1 cement 1 lime, rub up and gently put a nice flat sponge over it .(Wet sponge wring water out run over it and keep wash ing sponge out when it gets "clogged" up.
Thanks also to joe and roy.

It's good to know how it should be done (not that I'll be doing the re-repair, sounds far too skilled). But we are now much better informed than a few hours ago. Might have to deduct a bit from their bill to get a proper repair job done if they don't get it right.

Thanks again for all three speedy replies - appreciated.

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