Wind barrier on the inside, replace?

[mickeforsberg]

Hello everyone,

We are renovating our living room and taking down old tree tex at the same time. Underneath it was a wind barrier that tore in some places, so I thought I would replace it.

But... why was there a wind barrier on the inside? Do I even need to replace it? Could there be a negative effect of replacing it with today's wind protection?

Thanks for now!

 

[KnockOnWood]

Please provide more information.
How is the wall constructed, from outside to inside?
Age?
Where in the country is the house located?
And the rest of the house, the living room is only a part of it, right?

 

[mickeforsberg]

You need to provide a bit more info.
How is the wall constructed, from outside in.
Age?
Where in the country is the house located?
And the rest of the house, the living room is just a part of it, right?

How can I find out the easiest way?
From inside out there's treetex, windproof paper, tongue and groove, carbamide foam... beyond that, I'm not really sure. In the attic, there's a piece of black fabric protruding. Could it be some windproofing placed after the insulation? But how do I check that more thoroughly, by tearing down the tongue and groove?

The house was renovated in 1986, including a new facade, I suspect. I have little information about it. It seems the carbamide foam wasn't replaced then, oddly enough, which feels strange.

I haven't dismantled the rest of the house, but one might imagine it has the same construction?

Located in Skåne, inland outside Hässleholm

 

[Oldboy]

I believe that the asfapapp on the inside served two purposes:
1) To act as a wind barrier.
2) To provide moisture protection (against moisture migrating from inside, i.e., a vapor barrier).

The original construction should be maintained.

 

[mickeforsberg]

I believe that the asfapappen on the inside served two purposes:
1) To be windproofing.
2) To be moisture protection (against outgoing moisture from the inside, i.e., a vapor brake).

The original construction should be retained.

Okay! Is it the brown paper that is called asfapapp?

 

[Oldboy]

I don't know if the old version was, (or has become), brown. The one you buy for at least 20 years now is more likely black.

However, the weather protection paper that lies on fiberglass insulation is brown as far as I know. Maybe it's some form of waxed paper?

If it's brown and waxed paper, it's probably comparable to newer asfapapp.

 

[mickeforsberg]

Don't know if the old version was, (or has become), brown. The one you buy for at least 20 years is more likely black.

However, windproof paper that lies on fiberglass insulation is brown as far as I know. Maybe it's some form of waxed paper?

If it's brown and waxed paper, then it's probably comparable to newer asphalt paper.

Ah! Yeah, no it's not black... more like cardboard than cloth. Stiff and brown. Maybe it's rather the board you mentioned? No wax. It's been through some moisture at the window so the paper/board is a bit discolored. Shouldn't be a moisture barrier in the material then, should it?
Granted, it's possibly from -46 so...

 

[Oldboy]

Well, I think it's some kind of moisture repellent.

 

[mickeforsberg]

Well, I think it's some form of moisture barrier.

Stupid as I am, I didn't think to take a look among all the papers. The facade was replaced in 1986, it seems like everything else was replaced then too? It's only described as "papp", but at least it's significantly newer then.

 

[mickeforsberg]

After quite a bit of searching about what is best, I am somewhat more informed about the whole thing. As you say, it seems there was a vapor brake installed there, and I plan to replace it with similar vapor brake paper.

However, I can't install it as precisely as the old paper since it was located a bit above the ceiling and a bit down from the floor. It turns out to be a bit more of an undertaking than I thought when I started. Have I made a mess by unknowingly removing the old one, or is it not 100% critical? After all, it’s not a vapor barrier.

But in the ceiling, there wasn't one before, so all the moisture likely goes up into the roof instead. It's been like that for 33 years, so maybe it's not a huge problem. However, the additional insulation in the attic is mineral wool, and from what I understand, the house shouldn't be insulated with it, so I might need to address that. The original insulation is only urea foam.

But then I read that a vapor brake in the ceiling can be an advantage if you insulate extra... so much to think about, and so little knowledge

 

[Oldboy]

No, unfortunately, for practical reasons, it is often difficult to get the sealing layers as good during renovation as when they were newly built. It is just a matter of doing the best possible. In joints, gaps, and corners, it is appropriate to insulate thoroughly. It functions reasonably well as a vapor barrier. The most important thing is that no air has the slightest chance of moving through the floors, walls, and ceiling. You should also keep in mind that when the wind blows outside, large pressure and suction loads are created on the building's shell. This requires careful, thick insulating to prevent air from passing through.

Then, there will be neither more nor less vapor pressure in the ceiling regardless of how vapor-tight the walls are. What counts is the surface area x vapor permeability resistance. That is, the larger the surface and the worse the "vapor barrier value," the more moisture passes through.

If your attic (and facade) has so far managed without moisture damage, additional insulation could change that. Poor (thin) insulation allows heat to escape, and since warm air can carry more moisture, nothing happens. If the insulation is improved, it becomes colder in the attic, and the moisture can then condense there, causing moisture damage. Therefore, it is advisable to improve the vapor barrier in the ceiling.

If the ceiling consists of plasterboard, filled without cracks or open joints, thoroughly insulated around the walls, and sealed in electrical outlets for ceiling lamps, painting with oil-based paint should improve the vapor permeability resistance.

 

[mickeforsberg]

No, unfortunately, it is often practically difficult to make the moisture barriers as good during renovation as when they were newly built.
You just have to do the best possible. In seams, gaps, and corners, it is advisable to insulate properly. It works fairly well as a vapor barrier. The most important thing is that no air has the slightest chance to move through floors, walls, and ceilings. You also have to remember that when it is windy outside, large pressure and suction forces are created on the house's shell. Then careful and thick insulation is needed not to let air through.

Then there is neither more nor less vapor pressure in the ceiling regardless of how vapor-tight the walls are. What counts is the size of the surface x vapor resistance. That is, the larger the surface and the worse the "vapor barrier value," the more moisture travels through.

If your attic (and facade) have so far managed to avoid moisture damage, then an additional insulation can change that. Poor (thin) insulation lets heat escape, and since warm air can carry more moisture, nothing happens. If the insulation is then improved, it gets colder in the attic, and moisture can then condense there and cause moisture damage.
Therefore, it is appropriate to enhance vapor barrier in the ceiling.

If the ceiling, for example, consists of plasterboard, puttied without cracks or open seams, and properly insulated all around against the walls, and sealed in the electrical outlets for ceiling lamps, etc., then painting with oil paint should improve the vapor resistance.

Thanks for the tip about oil paint! I have put up plasterboard in the ceiling (only screwed up right now) already without any vapor barrier paper underneath, it would be a lot of work to take it down to put paper there, but then maybe I can help the situation by simply painting with oil paint? If I had known everything beforehand, I would have done it more properly, so I'm really annoyed about it. You don't want to do a half-assed job.

What do you mean by the air, that it shouldn't be able to blow through/drag? Or how should I prevent the air from having the slightest chance to get through the layers?

 

[Oldboy]

What do you mean by the air, that it shouldn't be able to blow/draft through? Or how should I prevent the air from having the shadow of a chance to get through the layers?

The classic method is to use insulation in gaps, joints, etc. where it can't be sealed in any other way.

 

[mickeforsberg]

Will probably have to frame the walls and ceiling instead and possibly insulate 45 mm with some eco-insulation, need to research that a bit more.
Then install a proper vapor barrier. Mostly because it feels better. However, the vapor barrier will end at the inner wall... so it can never be perfect in any way.