Were castles whitewashed on the exterior/interior?

Jan 2014
2,382
Westmorland
#12
It's an archaeological fact that many castles were whitewashed in the middle ages, but what I want to know is if this applies to all castles - not just some?
At least, the majority?

If not, would the majority of interior castle walls most certainly have been whitewashed (if not the exterior)?

I've come across a lot of digital reconstructions of castles and city fortifications, and most of them are not whitewashed - neither the exterior nor interior.
Why?
Whitewash (as we call it) was actually limewash. Limewash is the forerunner of modern paint. I don't know for sure, but I'd guess that limewash would not be terribly suitable for exterior use, as it is often quite powdery, requires lots of coats to cover anything and would wash off or dissolve pretty quickly in the rain.

Lime was used for mortar and also for plaster. The whole point of lime is that it is softer than the stones it binds together. So, when rain hits a lime mortared building, the rain can get into the lime mortar. Lime mortar allows a building to breath - the water can get in via the lime, but can also dissipate via the same route in fine weather. This reduces damp and condensation within. Over time, the lime is steadily eaten away by the weather and has to be replaced. Modern building techniques have replaced lime with cement. Cement is typically harder than the stone around it, meaning that the rain erodes the stone, not the cement. The longevity of the building is therefore affected. Use of cement also makes it harder for damp and condensation to escape from the interior of building.

For a building to breath, it is necessary to also use lime plaster and limewash on the interiors. If you use modern cement plasters or plasticky paint, the building still can't breathe.

If you look at limestone pavement, you'll see how rain (which is slightly acidic) eats away limestone (which is slightly alkaline). This is why so many cave systems can be found in limestone country.

If you want to draw attention to your fine exterior, I suppose you could endlessly lime plaster and limewash it, but you'd be better off using tiles, marble or light stones, perhaps as ashlar (a thin crust of smart looking stone mortared to a rough structural wall). Constant re-plastering or re-limewashing would only really be suitable for smaller, more domestic structures.

So, lime is essentially sacrificial to minimise damp and to ensure that the stonework of a building survives.
 
Likes: Todd Feinman
Oct 2013
6,153
Planet Nine, Oregon
#14
I think the OP was referring to the outside of structures as there is kind of a popular debate on how many exteriors were whitewashed. Plastering the interior was definitely a thing as some point but it is interesting that most of the debate I have followed is about the exteriors- plenty of books talk about cold, drafty, and damp castles- was the damp a reason not to plaster the interior or is that just conjecture and castles could be made quite snug?
Right. Very interesting!

'Plastering the interior was definitely a thing as some point but it is interesting that most of the debate I have followed is about the exteriors- plenty of books talk about cold, drafty, and damp castles- was the damp a reason not to plaster the interior or is that just conjecture and castles could be made quite snug?'

We have often heard about how drafty they were, but I don't know if that is accurate. It seems like in the winter that would be a lot of thermal mass to try and keep warm --every little bit might help. I think my post is outdated now!
 
Last edited: