Outside plaster making hollow sound?

There is cracks and a hollow sound in 5 places on my newly plastered outside wall. What could the problem be?

9 Answers

Chislehurst property solutions
30 Reviews, 100% Positive
First off it should be render or k rend & not plaster outside... Also if it sounds Hollow, It sounds to me like it has blown, which needs to be hacked off and re-done.
8th Dec 2020
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It sounds like your render has blown, the more the moisture gets into the cracks the worse it will get, especially if it rains then freezes
16th Dec 2020
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Dpc construct ltd
1 Reviews, 100% Positive
Could be the cause of many things first I have to see to tell what it's all about (could be air pocket ,dust creating air pocket,could be an area with no good pva application I have to see etc..
3rd Jan 2021
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A&GO
0 Reviews
Sounds like he's chopped it back but not prepped the wall properly to control the suction. The wall has then sucked out the water from the undercoat plaster which is now not adhering to the wall.
Hope that helps
1st Jan 2021
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Hi , this sounds like the render has de-bonded from the wall, allowing the air to get underneath. Which makes the hollow sound, i would have these areas re done to prevent them from completely falling down.
11th Jan 2021
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Mr.Yanev
0 Reviews
old plaster or there was water and this water when it evaporated left air between the wall and the plaster. it just needs to be torn down as much as possible and inspected again and plastered
2nd Mar 2021
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sonds like it has come away from the wall not bonded properly
2nd Feb 2021
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AA Trading
0 Reviews
The old walls may have been painted with an oil based paint which will repel the plaster
11th Feb 2021
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If crack and hollow sound like it blown
When had scratch coat applied did it allow 7 day in to cure before top coat ??
16th Jan 2021
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