An interesting feature we've uncovered in the renovation of our late 19C Lancashire cottage are these brass air vents that run around most of the house's ground floor.
The external triangular, almost masonic-looking, vents had always been visible from the outside; I thought they were some way of letting any dampness in the walls run outside. But when we started stripping wallpaper and wholly-unsuccessful cement tanking* from the internal walls, discovered that they run through the full thickness of the walls via clay pipes (like narrow, 1" drainage tiles) and terminate in circular brass vents inside (though some of the internal plates are missing and just the ends of the pipes are left).
Interestingly, not a single one remains unblocked. Where they appear on the inside, the external one is lost (or buried, unfortunately a later house next door has raised the ground level by about 1ft, giving rise to its own problems). Where the external ones exist, the corresponding internal vents are all plastered over.
They are fun little things though, and I was going to try and re-open them up where I can and leave them visible.
Has anybody else seen anything like them? I don't think that they are as old as the house as the mortar around them is a different colour to the rest, but I do think they are quite old.
*Cement tanking - what's your take on leaving this in place if it's not causing too much of a problem? We don't seem to have penetrating damp; there was a problem with condensation forming inside on north-facing walls which had been cement rendered and gypsum plastered. We hacked all this off and intend to redo in lime. Inside, the south wall is warmer, and is now not an external wall since another house was built adjacent. The gypsum plaster is ropy though and some has come off. Would you recommend taking all this off, and redoing in lime, or just a skim with gypsum?
The external triangular, almost masonic-looking, vents had always been visible from the outside; I thought they were some way of letting any dampness in the walls run outside. But when we started stripping wallpaper and wholly-unsuccessful cement tanking* from the internal walls, discovered that they run through the full thickness of the walls via clay pipes (like narrow, 1" drainage tiles) and terminate in circular brass vents inside (though some of the internal plates are missing and just the ends of the pipes are left).
Interestingly, not a single one remains unblocked. Where they appear on the inside, the external one is lost (or buried, unfortunately a later house next door has raised the ground level by about 1ft, giving rise to its own problems). Where the external ones exist, the corresponding internal vents are all plastered over.
They are fun little things though, and I was going to try and re-open them up where I can and leave them visible.
Has anybody else seen anything like them? I don't think that they are as old as the house as the mortar around them is a different colour to the rest, but I do think they are quite old.
*Cement tanking - what's your take on leaving this in place if it's not causing too much of a problem? We don't seem to have penetrating damp; there was a problem with condensation forming inside on north-facing walls which had been cement rendered and gypsum plastered. We hacked all this off and intend to redo in lime. Inside, the south wall is warmer, and is now not an external wall since another house was built adjacent. The gypsum plaster is ropy though and some has come off. Would you recommend taking all this off, and redoing in lime, or just a skim with gypsum?
