There is age-resistant foil/plastic and tape intended for the purpose used practically in all new construction.
Type http://www.byggmax.com/se-sv/Prod/PID-21022.aspx
I would have chosen that.
Best regards
Type http://www.byggmax.com/se-sv/Prod/PID-21022.aspx
I would have chosen that.
Best regards
Last edited:
We had the same problem and at the time, when Svensk Byggtjänst was located on Regeringsgatan, I went there and asked their building expert.
He thought that if the house is not drafty and evidently, in our case, has not molded in the 70 years it has already stood, then plastic in the walls during renovation might be a bit of overkill. In our house, there are three layers of windproofing in the old walls, so it's not drafty.
However, he recommended that we put plastic in the ceiling when we renovate it to protect it from the moisture we produce when living in the house. He suggested that we might pull that plastic down a bit on the walls upstairs.
His rationale was that since the old walls were dry, there is evidently no problem with the placement of the dew point and condensation of moisture in our existing walls. In the worst case, plastic could make things worse. But in the ceiling, it's always good to protect from moisture from the inside since moist warm air rises inside the house and thus wants to escape through the roof.
I felt that his explanations seemed reasonable, so in our case, it will be plastic in the ceiling, but not in the old walls.
We didn't discuss Goretex-like membranes at all then.
He thought that if the house is not drafty and evidently, in our case, has not molded in the 70 years it has already stood, then plastic in the walls during renovation might be a bit of overkill. In our house, there are three layers of windproofing in the old walls, so it's not drafty.
However, he recommended that we put plastic in the ceiling when we renovate it to protect it from the moisture we produce when living in the house. He suggested that we might pull that plastic down a bit on the walls upstairs.
His rationale was that since the old walls were dry, there is evidently no problem with the placement of the dew point and condensation of moisture in our existing walls. In the worst case, plastic could make things worse. But in the ceiling, it's always good to protect from moisture from the inside since moist warm air rises inside the house and thus wants to escape through the roof.
I felt that his explanations seemed reasonable, so in our case, it will be plastic in the ceiling, but not in the old walls.
We didn't discuss Goretex-like membranes at all then.
Hm, it becomes more and more interesting to follow your reasoning. I feel that it depends on so many factors, so one would have to do what seems best in our specific case by considering all your arguments.
Pinebar, in our case, the walls have held up well for 30 years (it was renovated in 1978), but I'm changing so much internally that I'm afraid I'm altering the conditions quite significantly. The energy consumption in 2005 was 51,000 kWh (!), so extensive insulation work is necessary. I have already added insulation to the roof, and part of the walls, and applied gypsum and plastered a 50 m2 room. There was previously a plank wall with significant drafts at the floor and edges, but now I have sealed it all.
It is in this work that I constantly think about whether or not to use plastic. In addition, there is an extension that I am building from the ground up myself, so it's important that I choose the right path to take.
Pinebar, in our case, the walls have held up well for 30 years (it was renovated in 1978), but I'm changing so much internally that I'm afraid I'm altering the conditions quite significantly. The energy consumption in 2005 was 51,000 kWh (!), so extensive insulation work is necessary. I have already added insulation to the roof, and part of the walls, and applied gypsum and plastered a 50 m2 room. There was previously a plank wall with significant drafts at the floor and edges, but now I have sealed it all.
It is in this work that I constantly think about whether or not to use plastic. In addition, there is an extension that I am building from the ground up myself, so it's important that I choose the right path to take.
As mentioned, there is no absolute truth. I avoid plastic in the walls as much as possible in my old house. The only time I have deviated from this is in the sauna, but then I think we are in a different discussion.
Some form of wind protection is necessary. For example, I can directly feel in the house when it's windy outside.
Then maybe you should thermograph the house to see WHERE the leaks are. Often there can be a major culprit that steals a lot.
Some form of wind protection is necessary. For example, I can directly feel in the house when it's windy outside.
Then maybe you should thermograph the house to see WHERE the leaks are. Often there can be a major culprit that steals a lot.
The whole problem lies in the fact that if you heat the entire wall, the water doesn't condense in it. But if you insulate an old wall so that it becomes cold, you get condensation in it if you don't have a vapor barrier. At what temperature you get condensation depends on air pressure and humidity. So if you have humid air that passes through the wall and the temperature drops too low... then you get condensation. That's why people warn against over-insulating old houses. It's easy to cross the invisible boundary. So either you insulate carefully or insulate a lot and use a vapor barrier.
It's quite interesting to see old brick houses that have been additionally insulated in half the house and you can see that the brick has frost damage where the wall has become cold on the outside... Maybe a little side note.
It's quite interesting to see old brick houses that have been additionally insulated in half the house and you can see that the brick has frost damage where the wall has become cold on the outside... Maybe a little side note.
v-g. I agree, the sauna and the bathroom are a completely different discussion. Good idea with thermography!
Hobbe. Good reasoning regarding cautious insulation. It feels like that's the right approach for me personally, and instead make sure there's no free draft in the cracks...
Hobbe. Good reasoning regarding cautious insulation. It feels like that's the right approach for me personally, and instead make sure there's no free draft in the cracks...
Borrowing the thread a bit as I am facing the same dilemma just before I can buy the materials to continue with my construction. I am building an apartment in an old barn/stable with parts from the mid-1800s in the frames, but we're talking only logs as the framework with regular planks on the outside. I am now building inside this and leaving the old construction in place, building partially around it. The initial idea is to use cellulose insulation that can transport some moisture out, as well as a diffusion-open construction with Halotex RS10 as the underlayment without an air gap (under a metal roof) and Halotex D50 as a vapor barrier on the inside. The challenging part is sealing where the logs in some places enter the partition walls from the outer wall. They can't exactly be temporarily cut off to insert the vapor barrier in between...
- Is it enough to seal around these as best as possible and pull the whole thing in a bit?
- Should one opt for this diffusion-open construction in this case or not?
- Is cellulose insulation the best option with its hygroscopic properties?
- Which vapor barriers are the most cost-effective, including all accessories like seam tape, etc.?
- Same question as above, but concerning the underlayment?
- Using exterior gypsum at the furthest point in the walls as wind protection. How does it work in combination with a vapor barrier? I want to achieve a resistance difference of about 5-10 times between the vapor barrier and the wind barrier/underlayment...
- Is it enough to seal around these as best as possible and pull the whole thing in a bit?
- Should one opt for this diffusion-open construction in this case or not?
- Is cellulose insulation the best option with its hygroscopic properties?
- Which vapor barriers are the most cost-effective, including all accessories like seam tape, etc.?
- Same question as above, but concerning the underlayment?
- Using exterior gypsum at the furthest point in the walls as wind protection. How does it work in combination with a vapor barrier? I want to achieve a resistance difference of about 5-10 times between the vapor barrier and the wind barrier/underlayment...
No, you don't need to do that, it takes care of itself over time ....andersmc said:
I built a guest room in the loft of a barn from the late 40s. I created an air gap on the outer side, then 120mm insulation, and then plastic. Some have said that I shouldn't use plastic because it's an old building and I'll probably keep it unheated most of the time. However, I can't really see any downside to using plastic. The idea of reverse condensation seems a bit forced to me. It could just as easily happen in any newly built house that has air conditioning.
hello
borrowing the thread a bit.
when it comes to older houses, you should be careful not to put plastic on the wall, as well as insulating from the inside, this can be the death of the wall.
just as imported anders said, you move the warm and cold *meeting* in the wall further in and rot occurs.
newly built walls should have the plastic. the best way is to place it right on the stud frame, then 2"2", 45 iso between osb, plasterboard, etc.
BUT: in this case, you should NEVER insulate more than 30% of the wall's insulation thickness after the plastic.
it requires a frame of 170 timber to have the margin right.
under the roof towards the attic or have a pitched roof, etc., where the plastic should obviously be used.
hope this helped you at all!
regards
carpenter estwing
borrowing the thread a bit.
when it comes to older houses, you should be careful not to put plastic on the wall, as well as insulating from the inside, this can be the death of the wall.
just as imported anders said, you move the warm and cold *meeting* in the wall further in and rot occurs.
newly built walls should have the plastic. the best way is to place it right on the stud frame, then 2"2", 45 iso between osb, plasterboard, etc.
BUT: in this case, you should NEVER insulate more than 30% of the wall's insulation thickness after the plastic.
it requires a frame of 170 timber to have the margin right.
under the roof towards the attic or have a pitched roof, etc., where the plastic should obviously be used.
hope this helped you at all!
regards
carpenter estwing
Estwing. That means according to your suggestion I put the plastic directly onto my current framework, which is 120x45 + 45x45. Then I put 45x45 on the plastic (inward towards the room), and then osb/drywall.
Right?
Right?
That is correct. If you do so, you will get 165mm of insulation outside the plastic and 45mm of insulation inside the plastic, and additionally, you will have an area where you can run the vp-rör inside the plastic, so you avoid running these through the plastic and making unnecessary holes in the plastic.
- M
- M
Gladh. Good, let's go with that, at least on the newly built section!!!
Thank you all for your opinions and knowledge! It's truly invaluable to be able to share your thoughts with others!
By the way, I installed the first two roof trusses today, what a feeling! Sooooo great when things start happening!
B
Thank you all for your opinions and knowledge! It's truly invaluable to be able to share your thoughts with others!
By the way, I installed the first two roof trusses today, what a feeling! Sooooo great when things start happening!
B