A little renovation plaster hardly does any harm. I would blow the walls with cellulose wool (if there are no refill openings in the attic?), then put on renovation plaster and then wallpaper. It usually looks much nicer as the thin plaster follows the walls and it looks more natural in old houses.
Like this:
Floor: remove the wooden floorboards, remove the shavings, add cellulose wool, lay down floor particle boards.
Walls: take down the boards, remove the shavings, add cellulose wool, nail up new wooden boards. Thin plaster.
Floor: remove the wooden floorboards, remove the shavings, add cellulose wool, lay down floor particle boards.
Walls: take down the boards, remove the shavings, add cellulose wool, nail up new wooden boards. Thin plaster.
Glass/mineral wool without a moisture barrier/plastic is not good. Forget it.
If you are going to replace the sawdust, you should use cellulose insulation. It is hygroscopic, which is suitable when there is no moisture barrier. This applies to both walls and floors. Sawdust is excellent but has slightly inferior insulation properties compared to new cellulose insulation (which has the same insulation values as glass/mineral wool). For old houses, the most important is that they are wind/draught-tight. If they are, the old sawdust insulation works fine.
If you are going to have a floating inner floor, the subfloor needs to be leveled. How this is done depends a bit on how uneven the existing floor is. Particle boards (22 mm) are clearly weaker than solid wood planks of >35 mm, and particle boards are made for a maximum of 60 cm center-to-center.
If the floor is too uneven, it might be easier to remove the old floor (which you can sell on Blocket or similar), even out the beams, and either widen them to reduce the center-to-center spacing to 60 cm/span to a maximum of 55 cm or cross-lay at 60 cm center-to-center.
If you are going to replace the sawdust, you should use cellulose insulation. It is hygroscopic, which is suitable when there is no moisture barrier. This applies to both walls and floors. Sawdust is excellent but has slightly inferior insulation properties compared to new cellulose insulation (which has the same insulation values as glass/mineral wool). For old houses, the most important is that they are wind/draught-tight. If they are, the old sawdust insulation works fine.
If you are going to have a floating inner floor, the subfloor needs to be leveled. How this is done depends a bit on how uneven the existing floor is. Particle boards (22 mm) are clearly weaker than solid wood planks of >35 mm, and particle boards are made for a maximum of 60 cm center-to-center.
If the floor is too uneven, it might be easier to remove the old floor (which you can sell on Blocket or similar), even out the beams, and either widen them to reduce the center-to-center spacing to 60 cm/span to a maximum of 55 cm or cross-lay at 60 cm center-to-center.
I believe the pricing for blown cellulose varies with the project/house, making it difficult to assess.
If they are already going out with the truck and guys to top up the wall cavities, they might as well do the floors. It's a quick and easy job once the floor is opened.
Just don't forget to windproof and rodent-proof before insulating.
If they are already going out with the truck and guys to top up the wall cavities, they might as well do the floors. It's a quick and easy job once the floor is opened.
Just don't forget to windproof and rodent-proof before insulating.
Rodent-proofing is done with solid materials and stuffing. There must be nothing that invites rodents. That means no air leakage, no smell, no light, no heat, and no easily gnawed material. Plastic, fabric, cloth, paper, and cardboard are completely unsuitable. Sheet materials such as gypsum, chipboard, plywood, etc. can work reasonably well provided they are completely flawless on the surface, i.e., no damage/indentation and not a single wrong nailing/screwing. Then all edges must be densely and tightly filled and have moldings, studs, or battens around them to be nailed/screwed against or clamped with.
The very best are brick, mortar, concrete, and clay/clay mortar.
The very best are brick, mortar, concrete, and clay/clay mortar.