Some concrete on our stone house

[cecinha63]

We are currently renovating a 300 year old stone house and after removing the internal plasterboard from the internal walls, we have come accros quite wide (1.5m wide x 2.9m high), floor to ceiling open doorways (our house is a terraced property that used to be part of a bigger house). Our builder has filled up a couple of the openings with concrete until I found out and stopped him. The rest of the house is being brought back to exposed stone and rendered with lime mortar, so I would say about 90% of the internal walls. So, my question is: will the areas filled with concrete and rendered with lime mortar be subjected to damp in years to come? The builder says that the doorways were never filled with stone in the first place and that, because most of the internal walls are of stones rendered with lime mortar, the areas with concrete won't cause any problems. In addition to that, it is now next to impossible to break up the concreted areas as they're about 45cm thick and it is going to cost a lot of money. Is by builder correct? Would greatly appreciate some insights. Thank you.

 

[DaveG]

I can’t say with complete certainty/guarantee but common sense tells me that if 90% of the surface area is breathable there is plenty of material for moisture to move and migrate and I’d not expect there to be a problem, particularly if as I understand it, these concrete “walls” are internal/shared with a neighbouring property?

 

[stuart45]

Has he used concrete blocks?

 

[cecinha63]

I can’t say with complete certainty/guarantee but common sense tells me that if 90% of the surface area is breathable there is plenty of material for moisture to move and migrate and I’d not expect there to be a problem, particularly if as I understand it, these concrete “walls” are internal/shared with a neighbouring property?

Thank you for reply. So, on the neighbour’s side it’s either bricks or plasterboard. When we removed the plasterboard on our side, there was this large empty space and then the neighbour’s plasterboard/ bricks. Sound proofing was also very poor. Our builder used breeze blocks on our side on the surface and then poured the concrete into the gap. It was then rendered with lime mortar. I am tempted to agree with you but not being an expert makes me quite nervous about this because we are spending a lot of money.

 

[cecinha63]

Has he used concrete blocks?

He used breeze blocks on the front to make a box and then poured the concrete in. The new wall was then rendered with air lime mixed with white cement which, according to the internet, is beneficial to the walls.Thanks for your response.

 

[cecinha63]

By the way, the house is in the south of France and the lime render used is very popular and suitable for ancient buildings.

 

[cecinha63]

My initial post said “dump”, I mean damp!

 

[a twig]

My initial post said “dump”, I mean damp!

Fixed

 

[Stevers]

It seems an odd way to fill the opening. The poured concrete will have introduced a lot of moisture to the fabric that may take a while to dry out. Let's hope some of that water doesn't go next door and ruin the neighbour's plasterboard!