Hultsfred House 1964

[Nille86]

Hello!

I have read and reread about having plastic in outer walls and I'm still not sure, I know many people have asked about this!

I have a Hultsfred house from '64 with a basement, the upper floor has fiber elements as a frame with 95×30 sections. The inside is covered with wind paper and fiber boards, the roof towards the attic has a painted board - planks - wind paper - then an attic with sawdust.

I have replaced the panel on one long side and added insulation with a 45 - wind paper - furring strip and panel, and now I'm going to do the other side too (The gables are brick).

1: Does it pay off significantly to insulate with a 45 on the inside as well? (I had a B in the energy declaration before I did the additional insulation outside)

2: If it does pay off, do I need to remove the wind paper in walls and ceiling and use plastic instead?

When we bought the house 16 months ago, we worked on 2 rooms that have outer walls. I didn't have much knowledge back then and was in a rush because we were expecting a child at the same time, so we tore off the wind paper and fiber boards on the walls and put plastic - OSB and gypsum. The plastic and wind paper in the ceiling are not sealed, we just put plastic on the walls without taping it to the ceiling, thinking that the wind paper in the attic covers the whole house.

Will this cause big problems in the future??

I have replaced the roof and installed 2 mold stoppers between each rafter.

I'm new here so excuse my long text, but I want to express myself as clearly as possible.

Best regards, Nille

 

[justusandersson]

Aren't the fiberelements 95x300 mm? Is the paper on the inside a black asphalt-impregnated paper? The gables are probably just clad with facade brick on the outside. Behind the brick, there is likely the same type of fiberelements.

 

[Nille86]

The fiber elements are probably 95x300 mm? The paper on the inside, is it a black asphalt-impregnated paper? The gables are probably just clad with facade brick on the outside. Behind the brick, there's likely the same type of fiber elements.

Yes, it should be 300. There are some black marks from the paper, so it could be some kind of asphalt situation.

 

[justusandersson]

I will respond somewhat generally. Increasing insulation from 95 mm to 185 mm always pays off in terms of energy savings. This assumes that you don't have other energy thieves such as drafty windows (both between the frame and wall and between the frame and sash). Interior additional insulation eats into the floor space, which should be factored into the calculation.

The bitumen paper on the inside was the vapor barrier of its time. It is not as vapor-tight as plastic film, and can be categorized as a vapor retarder with today's terminology. If the bitumen paper is intact, I think you should let it remain even if you add insulation on the inside. What you should never do is trap material between two relatively vapor-tight layers.

 

[Nille86]

I will answer somewhat generally. Going from 95 mm insulation to 185 mm always pays off in terms of energy savings. This assumes you don't have other energy thieves like drafty windows (both between the frame and the wall and between the frame and sash). Adding insulation internally will reduce the floor area, and that should be included in the calculations.

The asphalt paper on the inside was the vapor barrier of its time. It is not as vapor-tight as plastic sheeting and can be considered a vapor retarder by today's terminology. If the asphalt paper is intact, I think you should leave it as is even if you're adding insulation on the inside. What you must never do is enclose material between two relatively vapor-tight layers.[/QUOTE

I have 95 + 45 on the outside, wondering if the 45 indoors makes such a difference that it's worth relocating the radiators, electricity, and extending the fiber? The windows are old but will be replaced, and I also have geothermal heating, so the operating costs are relatively low.

 

[Nille86]

I have 95 + 45 externally, wondered if the 45 indoors makes such a difference that it's worth moving radiators, electricity, and extending fiber? The windows are old but are going to be replaced, also have geothermal heating so relatively low operating costs.

 

[justusandersson]

With those conditions, I wouldn't do it. It involves a lot of work and costs for little effect. There are other possibilities as well (wind + källare).

 

[Nille86]

With those conditions, I wouldn't do it. It will be a lot of work and cost for little effect. There are other possibilities as well (wind + basement).

If the paper isn't intact behind the fiberboard, can I just tear it and put plastic? I can't get to seal between the wall and ceiling without tearing down the ceiling unless there are other alternatives? I'm super grateful for the answers.

 

[Nille86]

If the pappen is not intact behind the fiberboards, can I just tear it out and install plastic? I can't access the seal between the wall and ceiling without tearing down the ceiling, unless there are other alternatives? I'm super thankful for the answers

I'm going to remove the fiberboards and install OSB and gypsum, but I'll probably skip the 45an

 

[justusandersson]

Damaged papp should be replaced. Without having been on site, I would choose new papp, like AC 350, over plastic. You cannot compare the conditions you have with those applicable to newly built prototype houses today. The fiberboards on the inside have a certain insulation value compared to OSB and plaster, but they are annoying in other ways.

 

[Nille86]

Damaged roofing felt should be replaced. Without having been on site, I would choose new roofing felt, like AC 350, over plastic. You cannot compare the conditions you have with those applicable to newly built model houses today. The fiberboards on the inside have some insulating value compared to OSB and drywall, but they are troublesome in other ways.

I will check the floor and see how well insulated it is, will also drain and insulate the foundation so that will do its part too thanks for the help