Hello. I bought an old house from the 1900s that I plan to renovate. Currently, I intend to build up the floor with 120" and add extra insulation on the existing one. I'm a bit curious because I heard (from a fairly knowledgeable person) that I can lay plastic on the existing floor before I raise it. Is this a good idea? Also, when I add insulation to the walls, should I let the plastic from the floor go up and join with the plastic on the walls, where I'm planning to add a 45 in terms of insulation?
Grateful for any answers.
Grateful for any answers.
It is very important that you do not get moisture in the old floor construction if you add insulation, and what does it look like under the old floor? I would never place plastic on a floor on top of an old wooden floor joist! I would find a way to ventilate the old floor using platon. Then I would choose cellulose with borate, which can balance variations in air moisture content between summer and winter.
there is sawdust in the old floor.. I have now spoken with a really knowledgeable person who said that no plastic in floors or walls, as it is dangerous to have such in old houses. Instead, I will use förhydringspapp on the walls and just put joists on the existing floor. Thanks for the answer that made me look into this a little closer!
Yes, age is just a number. Right?
Now, I don't know anything about your construction, so I'm just speculating a bit so you can think further in the right direction. It's about how effective your walls are! If you keep the old wall construction, then paper will do just fine! If you're using the house as a summer cottage and want to do no more than necessary, that sounds good.
On the other hand, if you're aiming for a more modern construction and thereby enjoying a better indoor climate and a more energy-efficient house, you'll probably need to put more insulation in the walls. Doing so keeps the heat in the house. This means that the outside of your walls becomes colder. This, in turn, leads to warm indoor air leaking into the walls, depositing a lot of water there. With a bit of unfavorable climate and general bad luck, you'll then get microbial growth there, and that's not so fun.
So - you can't mix construction methods. Either you build a wall with a modern design and make sure to have a layer that's sufficiently diffusion-tight to protect the wall from a lot of moisture. Or you go with a less energy-efficient wall in the old fashion, which is a bit more forgiving for convection-borne moisture. In such a wall, I hardly think diffusion is important relative to the moisture impact from convection - but that's just a guess!
Are you with me?
Now, I don't know anything about your construction, so I'm just speculating a bit so you can think further in the right direction. It's about how effective your walls are! If you keep the old wall construction, then paper will do just fine! If you're using the house as a summer cottage and want to do no more than necessary, that sounds good.
On the other hand, if you're aiming for a more modern construction and thereby enjoying a better indoor climate and a more energy-efficient house, you'll probably need to put more insulation in the walls. Doing so keeps the heat in the house. This means that the outside of your walls becomes colder. This, in turn, leads to warm indoor air leaking into the walls, depositing a lot of water there. With a bit of unfavorable climate and general bad luck, you'll then get microbial growth there, and that's not so fun.
So - you can't mix construction methods. Either you build a wall with a modern design and make sure to have a layer that's sufficiently diffusion-tight to protect the wall from a lot of moisture. Or you go with a less energy-efficient wall in the old fashion, which is a bit more forgiving for convection-borne moisture. In such a wall, I hardly think diffusion is important relative to the moisture impact from convection - but that's just a guess!
Are you with me?
Sure is
I understand exactly what you mean, we're talking about where the zero point in the wall will be. And there are certain rules about insulating inward, 1/3 of the total thickness of the wall is allowed, I believe, for there to be no problem with the zero point ending up in the wall when you insulate from the inside. It's intended to be a year-round house, and 45 inward is a start in this house to be able to utilize the regulation for electricity to the kitchen and outlets. The next step will be to add 45 from the outside as well, so the total added insulation is 9 cm thick.
With the modernization of an old house (i.e., plastic on the inner walls), moisture is trapped in the old construction in a completely different way. Sure, vents need to be installed to ventilate out any moisture. But the way they built houses in the past without any plastic works apparently even today in my house, so I think I'll stick to the vapour barrier paper and thereby allow my walls to breathe out any potential moisture that might arise. I'm not a professional either, but an old carpenter (now a site manager at a medium-sized company that does a lot of these jobs) explained it to me; he's one of the most knowledgeable people I know. Have you ever built in this way yourself? Any experiences with renovating old houses? Grateful for all the tips I can get regarding my project! You can't think of everything And experience is the best to learn from.
I understand exactly what you mean, we're talking about where the zero point in the wall will be. And there are certain rules about insulating inward, 1/3 of the total thickness of the wall is allowed, I believe, for there to be no problem with the zero point ending up in the wall when you insulate from the inside. It's intended to be a year-round house, and 45 inward is a start in this house to be able to utilize the regulation for electricity to the kitchen and outlets. The next step will be to add 45 from the outside as well, so the total added insulation is 9 cm thick.
With the modernization of an old house (i.e., plastic on the inner walls), moisture is trapped in the old construction in a completely different way. Sure, vents need to be installed to ventilate out any moisture. But the way they built houses in the past without any plastic works apparently even today in my house, so I think I'll stick to the vapour barrier paper and thereby allow my walls to breathe out any potential moisture that might arise. I'm not a professional either, but an old carpenter (now a site manager at a medium-sized company that does a lot of these jobs) explained it to me; he's one of the most knowledgeable people I know. Have you ever built in this way yourself? Any experiences with renovating old houses? Grateful for all the tips I can get regarding my project! You can't think of everything
And experience is the best to learn from.You're getting some curt answers here - I'm busy with something else:
>I completely understand what you mean, we're talking about where the dew point in the wall will be.
You never know - it depends on the moisture content inside, outside as well as the temperature inside, outside. So the position of this point varies over time.
>And there are certain rules about insulating on the inside, I believe it's 1/3 of the wall's total thickness that is allowed so that there won't be any issues with the dew point landing in the wall when insulating from the inside.
As far as I know, there are no rules that detail how it should look, but there are more general rules and recommendations in, among other things, BBR/BKR.
>The idea is for it to be a year-round house, and starting with 45 inside this house to draw some benefit from the electrical setup for the kitchen and outlets. The next step will be to add another 45 outside so that the total additional insulation is 9 cm thick.
Much work for little reward if you ask me.
>With modernizing an old house (i.e., plasticizing interior walls), the moisture is trapped in the old construction in a completely different way.
Well, you definitely don't want it out in the wall. Then you have to look at the ventilation too, but that's another matter.
>Sure, vents need to be installed to ventilate out any possible moisture. But the method they used to build before without any plastic in the house apparently still works today in my house, so I think I'll stick to the forhydringspapper and thus let my walls breathe out any potential moisture that might occur.
A risky construction if you ask me - but you have to calculate it to know!
>I'm no pro either, but got an explanation from an old carpenter (now site manager at a mid-sized company with a lot of such jobs) whom I know to be one of the most knowledgeable people I know.
Yes, everyone says something different - isn't it frustrating. And the more you read, the more confusing it gets. But beware of people who confidently say " - Just do it like this!"
>Have you ever built in this way? Experiences with renovating old houses? Grateful for any tips I can get regarding my project! You can't think of everything And experience is the best to learn from.
I've never renovated any house other than my own and my friends', but I work daily with these issues - albeit with slightly different applications.
I'm currently renovating my own house. I've designed several different walls that will be part of the construction. I want to show you an example - see attached pdf file. One curve shows the current moisture content, the other temperature. On the x-axis, you can see the different layers in the wall.
In the models, I've included a tricky climate scenario - namely +20°C / 35% RH inside and -10 / 90% RH outside. Look closely at what happens on the last wall (it's the wall as it looks today).
As you can see, the moisture condenses in the wall - this is what one does not want to happen. Note how the other walls handle the situation. You can especially see how well the wall against the wet room manages thanks to the moisture barrier!
Now, this is just an example - but it demonstrates an approach.
>I completely understand what you mean, we're talking about where the dew point in the wall will be.
You never know - it depends on the moisture content inside, outside as well as the temperature inside, outside. So the position of this point varies over time.
>And there are certain rules about insulating on the inside, I believe it's 1/3 of the wall's total thickness that is allowed so that there won't be any issues with the dew point landing in the wall when insulating from the inside.
As far as I know, there are no rules that detail how it should look, but there are more general rules and recommendations in, among other things, BBR/BKR.
>The idea is for it to be a year-round house, and starting with 45 inside this house to draw some benefit from the electrical setup for the kitchen and outlets. The next step will be to add another 45 outside so that the total additional insulation is 9 cm thick.
Much work for little reward if you ask me.
>With modernizing an old house (i.e., plasticizing interior walls), the moisture is trapped in the old construction in a completely different way.
Well, you definitely don't want it out in the wall. Then you have to look at the ventilation too, but that's another matter.
>Sure, vents need to be installed to ventilate out any possible moisture. But the method they used to build before without any plastic in the house apparently still works today in my house, so I think I'll stick to the forhydringspapper and thus let my walls breathe out any potential moisture that might occur.
A risky construction if you ask me - but you have to calculate it to know!
>I'm no pro either, but got an explanation from an old carpenter (now site manager at a mid-sized company with a lot of such jobs) whom I know to be one of the most knowledgeable people I know.
Yes, everyone says something different - isn't it frustrating. And the more you read, the more confusing it gets. But beware of people who confidently say " - Just do it like this!"
>Have you ever built in this way? Experiences with renovating old houses? Grateful for any tips I can get regarding my project! You can't think of everything
And experience is the best to learn from.I've never renovated any house other than my own and my friends', but I work daily with these issues - albeit with slightly different applications.
I'm currently renovating my own house. I've designed several different walls that will be part of the construction. I want to show you an example - see attached pdf file. One curve shows the current moisture content, the other temperature. On the x-axis, you can see the different layers in the wall.
In the models, I've included a tricky climate scenario - namely +20°C / 35% RH inside and -10 / 90% RH outside. Look closely at what happens on the last wall (it's the wall as it looks today).
As you can see, the moisture condenses in the wall - this is what one does not want to happen. Note how the other walls handle the situation. You can especially see how well the wall against the wet room manages thanks to the moisture barrier!
Now, this is just an example - but it demonstrates an approach.
Sure, you seem to know your stuff. But what is your opinion on how to proceed? Use plastic on interior walls? I'm a carpenter myself (although I don't have the experience and knowledge on all of this since I'm quite young). But I have been involved in two older houses being completely renovated and haven't seen any plastic in the walls, only tar paper both times. Sure, you can calculate things, but moisture will inevitably reach a wall construction at some stage. The main thing is not to have a construction where moisture regularly accumulates in the wall. With my construction, wouldn't the moisture be ventilated quite well?
45+45 with a cabin that has a log frame that already insulates well can't be all bad, I think it would do nicely. I'll include a link to an article about old houses and their insulation methods that suggests that the floor and ceiling alone would make a big difference in an old house. If you then add 10 cm of wool on the walls, this feels like a pretty well-insulated house to me.
http://www.gardochtorp.se/att-isolera-vinden-racker-langt.aspx?article=4247
You work theoretically with these questions? The transition from theory to practice can vary slightly. And I've heard from several people that I shouldn't involve plastic in old constructions. I don't live in a big city but in the countryside, so people are used to building with old houses, and experience says a lot, in my opinion. I'm not claiming that you're wrong in what you're writing because it sounds reasonable! But my question is simply, will it be wrong if I build the way I planned? Would you prefer plastic over wind paper when I have planned and built as I have? Many old houses have already been built (renovated) in this way today.
45+45 with a cabin that has a log frame that already insulates well can't be all bad, I think it would do nicely. I'll include a link to an article about old houses and their insulation methods that suggests that the floor and ceiling alone would make a big difference in an old house. If you then add 10 cm of wool on the walls, this feels like a pretty well-insulated house to me.
http://www.gardochtorp.se/att-isolera-vinden-racker-langt.aspx?article=4247
You work theoretically with these questions? The transition from theory to practice can vary slightly. And I've heard from several people that I shouldn't involve plastic in old constructions. I don't live in a big city but in the countryside, so people are used to building with old houses, and experience says a lot, in my opinion. I'm not claiming that you're wrong in what you're writing because it sounds reasonable! But my question is simply, will it be wrong if I build the way I planned? Would you prefer plastic over wind paper when I have planned and built as I have? Many old houses have already been built (renovated) in this way today.