House in Wales with repaired render cracks

Can cracked exterior rendered walls lead to damp inside your house?

The render that is on the exterior walls of a house is a hard wall coating that is designed to protect the bricks the house is made of, and to consolidate the walls and add strength to the structure but what happens when rendering cracks, and why does it crack?

We show what to do if this is happening to your home.

There is nothing worse than finding cracks in the outside of your house.

How would you know if they are just surface cracks or if the building needs re-rendering, after all render doesn’t last for ever?

Of course it depends on the extent of the damage and how much you care about keeping your property in good condition without having to spend a lot of money.

In many cases you do not have to be a tradesperson or builder to see if a crack is bad or not, however sometimes what looks like a small and very thin scar up the wall, could be hiding poor brickwork beneath, for example.

If you are particularly keen on keeping the property in good order, just finding one small crack, should not really be a cause for alarm of course, however when one finds LOTS of cracks, especially in one place, perhaps it is time to get them fixed?

What should I do about render cracks?

Well, you must certainly do something.

They cannot be left and ignored as slowly but surely they will get worse, potentially causing further and more costly issues.

Of course, and here is the dilemma, having your house painted each year by a decorator usually means that he will paint OVER any cracks in the walls as they often don’t care about the condition of your home, they just care about applying the paint and getting paid.

To your typical painter, rendering cracks are an interruption to his day!

When this is done year after year, a thick layer of paint can build up on the walls, masking the fact that underneath all that paint, strange things are afoot……

Your walls could be cracked without you knowing…

Yes all those layers of paint, or that awful spar dash on the house, the walls that you keep hurting yourself when you brush past it, can be hiding nasty cracks underneath.

Many people may think, ….oh well, I cant see them so it doesn’t matter….

…… however if your car was nice and shiny, but the underneath was rusty and falling apart, would you still say the same thing?

It really does pay to keep on top of any problems or defects around the house, even for your own financial security.

After all, most people have most of their money tied up in their home, so not looking after the place can be a recipe for disaster.

Cracks can come in all shapes and sizes. however most fractures in your walls will allow water to slowly seep into the house and possibly cause damp.

 Here is a house we did in last winter, in Lampeter, Wales, and as you can see, the property, being as it was by a main road, AND in an exposed location, gained more than its fair share of wall damage.

front of house with repaired cracks

This house did have some damp coming in, although it was not too bad, but the owner had bought the house recently, so we were brought in, as part of a programme of repairs, and refurbished the exterior of the property including the many rendering cracks seen here.

We had to fully repair the cracks or the exterior wall coating product we were using would not have lasted its expected 20 year lifespan.

What can cracks do to the structure of a house?

Well, as we discovered above, quite apart form the fact that the house itself will not actually LOOK very nice, having cracked walls can allow damp in to the house, so what happens next?

Well a number of things can happen, unfortunately they are all BAD things, so take note.

Water will find its way into your walls, via cracks.

If you look at the wall damage and you think its very thin, look ho long it is, because a tiny crack, but one that stretches for maybe 1o feet, is actually the same as having a big hole in the wall!

The crack will allow water to pass inside the wall. Even if it goes no further, that water will stay there until the winter.

That does not mean the water will disappear, oh no, it is going to turn to ICE!

Now, when you fill up your ice cube tray in the freezer with water, and then come back in a few hours, you will see the water level, now it is ice, has risen.

This is because water expands when it freezes, and yes, that happens inside your walls, meaning that the cracks increase in size and number, making your home more susceptible to damp.

How can I stop my walls from cracking?

To stop your walls from cracking they need to be weatherproof, so that the rain and wind, coupled with the cold weather, will not crack your walls again. Yes there is a solution.

Normal masonry paint, or even pebbledash, will NOT cure cracks and will NOT stop damp.

Weatherproof exterior wall coatings, from us, WILL stop cracks, in fact we GUARANTEE for 20 years that cracks will not appear on the coating to the exterior of your house.

What’s more, it will also look fab!

And for houses that need weatherproofing but not colour, then look at this clear wall coating system.

Call us now on (0800) 970 4928 to find out more and to book a survey.

Oh, and as Columbo said “…One more thing….”

This is the house above once we had finished. 🙂


If your home either has damp, or cracked rendering then call us now for advice.

Our exterior wall coating system does NOT crack and we guarantee that!

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