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What to do about cracked render?

Forgive me if I've used the wrong words, I'm by no means knowledgable about this! Small terraced house build in late 1800s and the render is cracked all over resulting in damp internal walls.
Should the render be removed and redone with lime?
Or should render be removed and house repointed and left with no render?
Or is there such a thing as a waterproof coating for the render that's already on there?

4 Answers from MyBuilder Bricklayers

Best Answer

You need to hack off the render and get it re rendered it’s likely that the render will come and take chucks of brick with it and leave small spots of old render be hide to hard to chip off and the brick wall be-hide will look horrible so I’d advise re rendering, if your house is as old as you say it is probably a good idea to use a lime based render I’ll steer clear of any modern systems like K render for an old building theses might cause you issues down the line with not allowing enough moment and the building to breath old buildings like to breath if possible.

Cement based render won’t have enough movement and will crack very quickly and again could cause you problems inside with not allowing the building to breath.

Is there any modern waterproof coatings ?

No idea probably a few I don’t know about to be honest, I can think of one thing that would seal the render but I think wouldn’t be aesthetically suitable for this and would make your home an eye sore.

Hope this helps

BT Roofing Services


Answered 15th Jul 2019

Once the rendering has cracked and water has got behind only one thing you can do is remove re stitch any broken cracked or missing bricks re render in two coats lime mix base coat and lime top coat once dry you can paint or leave natural render witch will look pal coulour it would be a waist of money to paint any protection on once you have cracking as damedged all ready been done hope this is of some help kind regards andy
Ambuilders southeast ltd


Answered 29th Jul 2019

Agree with the other comments on here that the render needs to be completely removed and a lime based render re applied with an integral waterproofing agent added to the mix. It your going to leave the render in its natural state then its very important that the renderer gauges out the mix exactly otherwise it will dry back like a patchwork quilt, The pores should be closed using a steel trowel and not sponged off. This will give a very hard and weatherproof surface that will last for years. The problem with this type of render is that when its hit with rainwater it does look unsightly, wet and patchy, and most people end up painting it anyway. If you decide to paint lime render the best paint is a silicate mineral paint , this reacts with the lime and becomes part of the render not just a surface dressing. Silicate mineral paints are expensive but out last traditional masonry paints 2 or 3 times so saving the hassle of painting every few years. KEIM PAINTS are in our opinion the world leaders in this type of paints and look fantastic over new renders. If you did not want to go to the expense of lime render, then you could re -point and repair the brickwork then paint it using a silicate mineral paint that again if done properly will out last masonry paint 2 or 3 times. Hope our comments together with the others on here help you make the right decision in regard to your property.
Regards Mike Taylor ( MASTEX )


Answered 2nd Aug 2019

Yes, totally agree with the above. Remove old render, re-render in lime base and re-paint with lime based emulsion. These older properties need to breathe hence painting with lime based paint.


Answered 12th Aug 2019

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