We are going to refresh the living room (=paint the ceiling and walls) in our apartment in a house built in the mid-40s. Today, we have unscrewed the baseboards and started removing the old wallpaper. We then discovered that there are quite large holes in some places near the floor (or rather dents in the lower part of the wall, since it doesn't go through the wall except in one spot). We thought we would fill these with house fix and filler. For example, there is a hole into the bedroom that was probably used to run wires between the rooms earlier.
In one corner, however, there is a hole we are a bit more doubtful about. The corner is in the wall towards the neighbor and against the facade. The hole goes diagonally down, towards the neighbor and downwards but mostly towards the neighbor, about 20 cm deep and about 5-7 cm in width. Can we fill that hole too or does it have a purpose? You can feel a draft from the hole (also from the other holes), and we would like to minimize that, but maybe it's supposed to be like that for ventilation purposes? Will it be too sealed if we fill all the holes/dents in the wall?
The wall in these holes/dents is red, so I assume it's brick, with some type of board as the inner wall. It's behind the inner board that it's dented. The outer facade of the building is plaster, if that matters.
Grateful for advice!
In one corner, however, there is a hole we are a bit more doubtful about. The corner is in the wall towards the neighbor and against the facade. The hole goes diagonally down, towards the neighbor and downwards but mostly towards the neighbor, about 20 cm deep and about 5-7 cm in width. Can we fill that hole too or does it have a purpose? You can feel a draft from the hole (also from the other holes), and we would like to minimize that, but maybe it's supposed to be like that for ventilation purposes? Will it be too sealed if we fill all the holes/dents in the wall?
The wall in these holes/dents is red, so I assume it's brick, with some type of board as the inner wall. It's behind the inner board that it's dented. The outer facade of the building is plaster, if that matters.
Grateful for advice!
Okay, so we just fill it in then. We've determined that it will probably take several packages of house fix, so building foam is probably easier then. Does it make any difference for sound properties? (The house is overall very lyhört)
Given the size of the holes, the difference might be marginal, but more massive material will obviously dampen better. Building foam is very light and therefore practically provides no dampening. A bag of plaster costs basically 200 or less, so it might end up being almost more expensive to buy foam and a smaller bag (if available). To reduce the amount of mortar needed, you can always find a suitable scrap piece of brick or light concrete to fill with.
Construction foam dampens sound significantly better than mortar!
Since construction foam becomes foam, it dampens sound waves much more than a solid and hard material like cement, which "transmits" sound waves!
Foam sealant costs maybe 50 SEK for a can, and it's more than enough!
Be careful with gypsum plaster so you don't build out too much, it's very hard and difficult to sand. Fill in the last bit with regular hand filler and sand instead, it usually turns out better if you're inexperienced...
Since construction foam becomes foam, it dampens sound waves much more than a solid and hard material like cement, which "transmits" sound waves!
Foam sealant costs maybe 50 SEK for a can, and it's more than enough!
Be careful with gypsum plaster so you don't build out too much, it's very hard and difficult to sand. Fill in the last bit with regular hand filler and sand instead, it usually turns out better if you're inexperienced...