Repainting 1 year old external render

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Hi there, started a new thread after reading the painting external render thread.

Basically we had a seating area and various flower beds built out of brick and block (on various levels) and rendered last year. It was painted with a couple of coats of Sandtex but over the winter lots of render has blown off, and now every time I go out in the garden I see a fresh layer of paint peeling off.

I read on the other thread about thinning down the first coat of paint so that it gets soaked up rather than just being a layer of paint 'on top' s.o it looks like this is exactly what has happened :cry: .

How should I prepare this now? Should I be applying some sort of sealant? Im paranoid that if I scrape off all the loose bits now and repaint, that it will all come off again and be a gigantic paste of time. I thought with the better weather that what was going to come off would come off, but I keep seeing more new paint bubbles....

Any help much appreciated..
 
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If as you say the the render has in part blown then perhaps this is not a problem with paint adhesion but the render itself.

Dec
 
If there is nothing on the inner side of the flower bed to protect the wall then the damp will penetrate the wall and push the render and paint off. It wont matter how good the preparation or the paint is until this is rectified. Ideally it should be lined with DPC or something similar before filling with soil.
 
If as you say the the render has in part blown then perhaps this is not a problem with paint adhesion but the render itself.

Dec

Yep I'm inclined to agree with you there, but what do you do? Cut out all the render and start again... On the whole the majority of it seems to be OK (so far...)
 
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If there is nothing on the inner side of the flower bed to protect the wall then the damp will penetrate the wall and push the render and paint off. It wont matter how good the preparation or the paint is until this is rectified. Ideally it should be lined with DPC or something similar before filling with soil.

Ironically the insides seem to be ok, its the external face that has had damage. It all seems to be where the snow and ice built up over the winter. I have had a couple of quotes, and one guy did say it should have been lined, but when looking at it now said there was not a lot of options for lining now...

:unsure:
 
The render could have failed because of lack of adhesion did you add pva to the mix, or apply it to the masonry. Look at this way the water/moisture from inside will constantly be searching for an escape route this will cause your paint system to bubble and fail. Take a look at Robbies post for you need to seal from within to give your paint any chance of survival.

Dec
 
The render could have failed because of lack of adhesion did you add pva to the mix, or apply it to the masonry. Look at this way the water/moisture from inside will constantly be searching for an escape route this will cause your paint system to bubble and fail. Take a look at Robbies post for you need to seal from within to give your paint any chance of survival.

Dec

I didnt do it myself, but was told that pva was added to the mix, but the guys I have had round to quote have commented that the scratch was not deep enough, and commented on the colour i.e. poor mix etc...

OK, so digging out hundreds of plants is not really a solution.. what options are there for me?

http://bit.ly/kBe5to

This album gives you an idea of what I am dealing with.. there are not any pictures of blown render in there, but you get an impression of the issue.
 
If the render is low down then it shouldn't be there anyway. You need to terminate it about a foot up from the ground with a metal bead which brings the water out and away from the house. Google 'bellcast bead'. Neither should PVA have been used. You need SBR.
 
If the render is low down then it shouldn't be there anyway. You need to terminate it about a foot up from the ground with a metal bead which brings the water out and away from the house. Google 'bellcast bead'. Neither should PVA have been used. You need SBR.

Its not on a house its on an external seating and bedding area...
 
Hi Mark,

I've just been enjoying a slideshow of your garden and must admit it's pretty impressive.

However, as the sunken seating area is so deep, I imagine that the walls are holding an awful lot of moisture behind them. As far as I could see, there were no drainage holes in these walls which may be a possible solution to the problem. Ideally, as has been stated, the inside of the walls would probably have benefitted from some form of waterproofing/membrane but it's a bit late for that now, as you say. :(

Other than drainage holes, I can't really think of another way forward but feel you may benefit by asking a few questions in the Building Forum to see if any of the guys there can suggest something.

Hope so! :)
 
That may be the best idea yet I think you have a tremendous task on your hands.

Dec
 
If the render is low down then it shouldn't be there anyway. You need to terminate it about a foot up from the ground with a metal bead which brings the water out and away from the house. Google 'bellcast bead'. Neither should PVA have been used. You need SBR.

Its not on a house its on an external seating and bedding area...

You've got no hope then. It needs tackling from inside - not outside.
 
Hi Mark,

I've just been enjoying a slideshow of your garden and must admit it's pretty impressive.

However, as the sunken seating area is so deep, I imagine that the walls are holding an awful lot of moisture behind them. As far as I could see, there were no drainage holes in these walls which may be a possible solution to the problem. Ideally, as has been stated, the inside of the walls would probably have benefitted from some form of waterproofing/membrane but it's a bit late for that now, as you say. :(

Other than drainage holes, I can't really think of another way forward but feel you may benefit by asking a few questions in the Building Forum to see if any of the guys there can suggest something.

Hope so! :)

Thanks for that. I hadn't thought of drain holes, and presumably neither had the builder. Does nobody think its a little strange that the builder didn't factor in that the retaining parts would need lining/protection? Again though, I have to point out that the only places that the render has blown off is where snow was laid against it. I think everyone has concluded that this is due to the water behind the walls, which for the most part is not the case (because most of the blown render is not on an earth retaining wall).

There is also a hell of a lot of conflicting comments...

If the general consensus was to pull all the plants and redo the whole lot then I might consider it. But that sounds like a logistical nightmare...
 
I would really post this on the Builders Forum before you go drilling anything, they may not have any magic cure, yet they may be able to offer you with a few more alternatives.

Dec
 
I would really post this on the Builders Forum before you go drilling anything, they may not have any magic cure, yet they may be able to offer you with a few more alternatives.

Dec

OK thanks for that I'll start up a new thread. But going back to the original post, on the areas that the render is good (not on the earth retaining parts) and the sandtex has peeled off how should I prepare/repair it....
 

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