Dear all,
I'm a new member and stumbled across your forum after a series of non-sensical advice from builders and surveyors (i.e. that we need to inject a damp proof course because the lime plasterwork is a bit damp). I found the 'Lime Plaster and Bathrooms' post really interesting but am still pretty stuck on how to build our downstairs bathroom. I'm new to old buildings but am trying to learn as fast as possible.
As a quick background we have moved our young family to a house outside Berlin in former East Germany. It is a hundred years old and it looks to have been built to last from the materials they used. However, the years 1939 to 1989 were not kind, so we have some work to do improving on the repairs and maintenance that were carried during that time with very scant materials, if at all.
The question I want to ask is how to construct a bathroom on the ground floor. The thing is that the floor is BARE SAND. We took up an existing thin layer of weak concrete with tiles on it, and the sand underneath was a bit damp but seems to be drying out.
The lime plaster on the walls is damp towards the bottom and sounds a bit hollow in places but is more or less intact. (The only thing that worries me is when I dig down a bit under the sand to look at the bricks of the internal wall foundations, the mortar seems very friable, barely more solid than the sand - not sure if that's a problem).
The adjacent rooms are interesting - they are the same sand floor but with wooden floorboards - the beams are literally laying on the sand. I could easily believe they have been laying there as long as the house, and guess the room where we want to make the bathroom they laid concrete and tiles because the wood rotted faster as it was the kitchen area. Anyway the beams we took out are more or less rotten, but the boards on top of them are actually useable so we're going to take our neighbours' advice and lay some new beams down on the sand and put the boards right back. There will be some air gaps between the wonky old boards, and we'll also leave gaps round the edges by the walls to maximise ventilation...
...but in the room that had the tiles we intend to install a bathroom. Would the same kind of wooden floor be a good idea, it being such a high-humidity area? On the other hand, if we try and seal the floor, won't that stop any humidity from the sand below from evaporating and push it towards the walls?
The plumbers are pressuring us to put a waterproof membrane over the floor and walls, then tile everything (a German 'standard bathroom') or they can't offer us a workmanship guarantee. But this seems like an idea geared towards new houses. I wondered could we put stud walls and a kind of floating floor that were totally waterproof and somehow ventilate behind it (though we don't have any airbricks in the walls)? Anyone with experience have any better ideas?
Thanks a million!
For extra information: All walls are original lime plaster. The building has no DPC (damp proof course). The bathroom has one wall to the exterior, a thick single layer of fieldstones/soft-fired brickwork with lime mortar. However, the whole building has been rendered about 15 years ago in what appears to be a cement/lime render and thickly painted. Surprisingly the render seems in great condition, except from ground level to about 70cm high where it's starting to crumble and the paint is falling off - I plan to replace this bit with a lime render once I've learned more about it.
Cheers,
Ben
I'm a new member and stumbled across your forum after a series of non-sensical advice from builders and surveyors (i.e. that we need to inject a damp proof course because the lime plasterwork is a bit damp). I found the 'Lime Plaster and Bathrooms' post really interesting but am still pretty stuck on how to build our downstairs bathroom. I'm new to old buildings but am trying to learn as fast as possible.
As a quick background we have moved our young family to a house outside Berlin in former East Germany. It is a hundred years old and it looks to have been built to last from the materials they used. However, the years 1939 to 1989 were not kind, so we have some work to do improving on the repairs and maintenance that were carried during that time with very scant materials, if at all.
The question I want to ask is how to construct a bathroom on the ground floor. The thing is that the floor is BARE SAND. We took up an existing thin layer of weak concrete with tiles on it, and the sand underneath was a bit damp but seems to be drying out.
The lime plaster on the walls is damp towards the bottom and sounds a bit hollow in places but is more or less intact. (The only thing that worries me is when I dig down a bit under the sand to look at the bricks of the internal wall foundations, the mortar seems very friable, barely more solid than the sand - not sure if that's a problem).
The adjacent rooms are interesting - they are the same sand floor but with wooden floorboards - the beams are literally laying on the sand. I could easily believe they have been laying there as long as the house, and guess the room where we want to make the bathroom they laid concrete and tiles because the wood rotted faster as it was the kitchen area. Anyway the beams we took out are more or less rotten, but the boards on top of them are actually useable so we're going to take our neighbours' advice and lay some new beams down on the sand and put the boards right back. There will be some air gaps between the wonky old boards, and we'll also leave gaps round the edges by the walls to maximise ventilation...
...but in the room that had the tiles we intend to install a bathroom. Would the same kind of wooden floor be a good idea, it being such a high-humidity area? On the other hand, if we try and seal the floor, won't that stop any humidity from the sand below from evaporating and push it towards the walls?
The plumbers are pressuring us to put a waterproof membrane over the floor and walls, then tile everything (a German 'standard bathroom') or they can't offer us a workmanship guarantee. But this seems like an idea geared towards new houses. I wondered could we put stud walls and a kind of floating floor that were totally waterproof and somehow ventilate behind it (though we don't have any airbricks in the walls)? Anyone with experience have any better ideas?
Thanks a million!
For extra information: All walls are original lime plaster. The building has no DPC (damp proof course). The bathroom has one wall to the exterior, a thick single layer of fieldstones/soft-fired brickwork with lime mortar. However, the whole building has been rendered about 15 years ago in what appears to be a cement/lime render and thickly painted. Surprisingly the render seems in great condition, except from ground level to about 70cm high where it's starting to crumble and the paint is falling off - I plan to replace this bit with a lime render once I've learned more about it.
Cheers,
Ben