The house in question is a 1970s villa with an unfinished attic. The attic floor is made up of the lower frames of the trusses that lie at 120 cc. Between these, there are additional floor joists. In other words, there are floor joists at about 60cc. The span is 3m-4m. It varies in different places. I'm unsure about the height of the joists, but I guess around 220mm. The ceiling below is rough-sawn boarding nailed under the trusses and joists, followed by gypsum. Currently, there is a loose 22mm chipboard floor on the attic floor. By loose, I mean it is not glued (neither at the joints nor to the floor joists) or screwed. In short, it is temporarily placed. Naturally, there is insulation in the spaces between the joists.
Currently, I find this construction extremely flimsy and noisy. Footstep sounds go straight through, etc. If in the future I wish to finish the attic, I must start by thinking about how to optimize the floor structure. Note that the height in the attic is limited. So I would prefer not to add too much height to the entire floor structure.
Bracing between the floor joists is probably a good idea. Could it be beneficial to supplement with additional beams, like lightweight beams or similar?
There are different variations of soundproof flooring structures. For instance, I have seen examples where the chipboard floor is laid floating on the framework with a dampening material between the framework and chipboard. Could that be something worth considering? On the other hand, you want to screw-glue the chipboard to the joists for maximum stability.
Could one place extra lightweight beams between each existing floor joist, allowing them to rest on the outer walls and central wall? These would be dimensioned slightly higher in height. This way, you entirely separate the floor and the ceiling below. Could that be a good idea? That is, the existing framework supports the ceiling while the new extra beams support the floor.
Does anyone have good examples/ideas here?
Currently, I find this construction extremely flimsy and noisy. Footstep sounds go straight through, etc. If in the future I wish to finish the attic, I must start by thinking about how to optimize the floor structure. Note that the height in the attic is limited. So I would prefer not to add too much height to the entire floor structure.
Bracing between the floor joists is probably a good idea. Could it be beneficial to supplement with additional beams, like lightweight beams or similar?
There are different variations of soundproof flooring structures. For instance, I have seen examples where the chipboard floor is laid floating on the framework with a dampening material between the framework and chipboard. Could that be something worth considering? On the other hand, you want to screw-glue the chipboard to the joists for maximum stability.
Could one place extra lightweight beams between each existing floor joist, allowing them to rest on the outer walls and central wall? These would be dimensioned slightly higher in height. This way, you entirely separate the floor and the ceiling below. Could that be a good idea? That is, the existing framework supports the ceiling while the new extra beams support the floor.
Does anyone have good examples/ideas here?
Self-builder
· Stockholm
· 8 227 posts
It sounds like a relatively normal construction; unclear why it would be noisy in itself?O Olf Oggler said:
If you add nogging between the joists (so you get a more stable framework) and screw the chipboard on top, it is like most floor structures between floors, I would say?
If you then add a vinyl floor, or click-flooring with good foam underneath, it should work?
To reduce deflection, it helps to cross-brace or install nogging, and to screw-glue the subfloor. To reduce noise, you could fill the joists with wood chips/sawdust if it hasn't already been done. Chips dampen sound better than mineral wool but insulate less against cold, so this is perhaps something worth waiting with until the attic is going to be heated.
A small related question. What do you do with the vapor barrier when furnishing an attic? There is currently a vapor barrier directly beneath the existing joists. That is, between the joists and the roof boards that make up the ceiling of the floor below.
The vapor barrier that should be in the sloped ceiling in the attic. How should I finish it where the "wall" meets the floor?
The vapor barrier that should be in the sloped ceiling in the attic. How should I finish it where the "wall" meets the floor?
I didn't understand much of that. As it stands, there is a vapor barrier in the ceiling of the lower floor. That vapor barrier then goes down the walls of the lower floor. But when I install the vapor barrier in the attic I am going to renovate, it won't be able to connect to the lower floor's vapor barrier.
This whole vapor barrier thing seems to be somewhat of a paradox in general. When you read about it, it's insanely important that it is airtight. Every staple must be taped over. And if you get a nail hole, it's like a disaster. But meter-sized gaps between floors. What do you do there then?
This whole vapor barrier thing seems to be somewhat of a paradox in general. When you read about it, it's insanely important that it is airtight. Every staple must be taped over. And if you get a nail hole, it's like a disaster. But meter-sized gaps between floors. What do you do there then?
Self-builder
· Stockholm
· 8 227 posts
In an old house, maybe a vapor retarder is better, so moisture can escape if it gets in through, for example, gaps.O Olf Oggler said:
A vapor brake is probably better. But you also want it to be tight. As much as possible, at least.
Has anyone ever seen moisture damage caused by an untight vapor barrier? I can understand it happening above bathrooms and other places where the moisture load is high. But in regular rooms?
My vapor barrier between floors and an uninsulated attic is totally perforated by fastenings of tongue-and-groove boards, holes for electrical conduits, and other things. So far, I haven't seen a trace of moisture. However, you can see in the insulation that it gets dirty from leaking air. I assume the insulation gets dirty like a filter.
Has anyone ever seen moisture damage caused by an untight vapor barrier? I can understand it happening above bathrooms and other places where the moisture load is high. But in regular rooms?
My vapor barrier between floors and an uninsulated attic is totally perforated by fastenings of tongue-and-groove boards, holes for electrical conduits, and other things. So far, I haven't seen a trace of moisture. However, you can see in the insulation that it gets dirty from leaking air. I assume the insulation gets dirty like a filter.