Dark spots

[JasperVe]

We own a listed (monumental) house from around 1800 in the Netherlands. The front façade has always had a cement-based stucco finish with a block pattern. About 20 years ago this stucco layer was renewed.

We bought the house about a year and a half ago and have since noticed high humidity levels in the cavity that was created between the insulation and the original single-brick exterior wall. After rain, there are always several dark patches on the façade that remain visible for days or even weeks, and they never really return to the same colour as the rest of the wall.

Could this indicate that water is penetrating through the stucco in those specific spots?

 

[bobski]

I think they're 'holding' water for longer than the other areas.

So yes , more likely penetration could happen there than the others.

Was the whole facade done at the same time, or were there repairs?


There are ways to prevent this happening.







That is some scaffold!

 

[Monkey Boy]

yes

 

[JasperVe]

I think they're 'holding' water for longer than the other areas.

So yes , more likely penetration could happen there than the others.

Was the whole facade done at the same time, or were there repairs?


There are ways to prevent this happening.



That is some scaffold!

Thanks for your reply!

Do you mean that the 'holding of water' is causing the penetration or the other way around?

The facade was done twenty years ago but I think they did some repairs about five years ago. I don't think they did the repairs in these spots though.

I see some hairline cracks in certain spots and there are also patches which definitely came loose from the wall sounding hollow. These spots however don't have the wet colour after rain.

 

[JasperVe]

I received some additional information. It seems they did some restoration work in 2022. The 'wet' spots seem to pretty much match with the parts they replaced. Could it be just the plaster which has a different composition?

 

[bobski]

Thanks for your reply!

Do you mean that the 'holding of water' is causing the penetration or the other way around?

The facade was done twenty years ago but I think they did some repairs about five years ago. I don't think they did the repairs in these spots though.

I see some hairline cracks in certain spots and there are also patches which definitely came loose from the wall sounding hollow. These spots however don't have the wet colour after rain.

The first one.

I received some additional information. It seems they did some restoration work in 2022. The 'wet' spots seem to pretty much match with the parts they replaced. Could it be just the plaster which has a different composition?View attachment 83229

Yes

Probably a poorer mix quality?


I'd probably blast (pressure wash) until immaculate - and then cream it myself if it's bare render.

 

[FreeD]

The first one.









Yes

Probably a poorer mix quality?


I'd probably blast (pressure wash) until immaculate - and then cream it myself if it's bare render.

What type of cream whipping or sour?

 

[bobski]

Whipping.




By wykamol.