Lime render

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Forgive my ignorance but are all rendered houses done with lime mortar.
Seen a lot of items saying no sand and cement renders ever as they can trap moisture.
Thinking of rendering my external walls on 1930s build
 
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Render on solid walls must be lime render. Render on cavity walls contain cement.

Solid walls breathe through the mortar joints. Repointed with cement mortar and/or rendering with cement render stops the wall breathing, hence why they become very damp inside.
 
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Render on solid walls must be lime render. Render on cavity walls contain cement.

Solid walls breathe through the mortar joints. Repointed with cement mortar and/or rendering with cement render stops the wall breathing, hence why they become very damp inside.
And cause brick spalling
 
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dontbelieveawordofit

your 1930’s walls could very well contain as many bricks as stones . not to mention timer window and door lintels . so watcha gonna do?
To say that lime render or cement render is right or wrong is a myth and far too simplistic.
how a property is treated inside is as important .
technically though even cement renders contain lime as its present in cement.
 
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What does " your 1930's walls could very well contain as many bricks as stones" mean? Stones in a typical 1930's house?
What does mention of "timber ... lintels" have to do with the OP's question?
"how a property is treated inside" means what? "simplistic" how?
To say lime or cement render is a myth is pretty wrong.

Portland cement powder and NH Lime powder are miles apart in many ways - they affect render and mortar in different and distinctive ways
Technically, even scrap iron is an ingredient in cement but it has virtually nothing to do with renders or mortars on site.

sweet I’ll use cement instead of an rsj in future since it contains iron ;)))
Thanks guys for the input. I think to be fair I’d use the lime anyway as seems the safest bet
 
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dontbelieveawordofit

26DFCE55-665D-4754-A946-559C36991A8E.jpeg

gasplumber, both properties in the picture belong to me. I dash rendered them both about 22 years ago.
the points I was trying to make earlier are in both houses.... the one on the left is all brick , I cement rendered it . theres no cracks and no internal damp.
the wall of the house on the right is circa 1895 and largely stone but every room on that wall has a fireplace. theres probably a 60/40 brick to stone ratio in that wall so i cement rendered that too. there’s no cracking , nothing has blown and there’s no damp internally. if the wall had been more stone i’d have lime rendered it.
just one more point, someone mentioned that mortar joins allow moisture out and allow walls to breathe ,that’s not wholly correct , given the right circumstances mortar joins will allow more in than it'll let out.
and the majority of ‘solid stone’ walls are not solid at all. they're made up of an inner and outer , and rubble filled , which allows passage of air just like a modern cavity.
 
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