Hello knowledgeable forum!
I could really use some help understanding if lättbetong is problematic in terms of radon risk.
We are looking at a house and have obtained the technical description from when the house was built (1965). In this description (attaching image), I can decipher (not very easy trying to decode old handwriting...) the word "lättbetong" in at least three places. For example, under the headings insulation, interior foundation walls, and floor structure under the bathroom.
1. Is this a problematic construction, given the info above?
2. What can we do to determine how big the problem is before we sign the purchase contract?
Appreciate all the help
Thanks!
I could really use some help understanding if lättbetong is problematic in terms of radon risk.
We are looking at a house and have obtained the technical description from when the house was built (1965). In this description (attaching image), I can decipher (not very easy trying to decode old handwriting...) the word "lättbetong" in at least three places. For example, under the headings insulation, interior foundation walls, and floor structure under the bathroom.
1. Is this a problematic construction, given the info above?
2. What can we do to determine how big the problem is before we sign the purchase contract?
Appreciate all the help
Thanks!Do you think it can be solved with ventilation?
No,
Lightweight concrete is often an excellent material that neither moves like wood nor has a risk of mold or fire. Additionally, not all lightweight concrete contains radon.
However, some lightweight concrete was made from uranium-rich alum shale, which emits radon.
To know if the lightweight concrete in your house emits radon, you need to measure it. But if you can see that it is white, the risk of radon is less than if it is blue. (However, not all blue lightweight concrete is radioactive either)
Edit: And if it does emit radon, better ventilation usually solves the problem.
Lightweight concrete is often an excellent material that neither moves like wood nor has a risk of mold or fire. Additionally, not all lightweight concrete contains radon.
However, some lightweight concrete was made from uranium-rich alum shale, which emits radon.
To know if the lightweight concrete in your house emits radon, you need to measure it. But if you can see that it is white, the risk of radon is less than if it is blue. (However, not all blue lightweight concrete is radioactive either)
Edit: And if it does emit radon, better ventilation usually solves the problem.
so the radon scare is a bit exaggerated?Anders243 said:
One can measure. Radon can be measured both with short-term measurement (holding up an instrument). The measurement is quite uncertain. Also with long-term measurement. A sensor is placed for a few months and then sent in for analysis.
In this case, it is about possible radon from blåbetong (blue-gray lightweight concrete). Not all blåbetong emits radon.
When the uranium that may be in the lightweight concrete decays, gamma radiation is generated that can be measured easily. When it decays, the gas radon is formed. Gamma radiation is considered harmless in these contexts. But if there is gamma radiation, it is known that it is uranium-containing blåbetong.
Radon in turn decays and then emits alpha radiation. Alpha radiation is dangerous (obviously depends on the concentration) when it hits living tissue. But alpha radiation does not penetrate anything; a sheet of paper is enough to stop the radiation. When it is generated in the room and hits you, it does not penetrate the outer layer of the skin, which consists of dead tissue. Therefore harmless.
BUT you breathe in the air, and the radon that gets into the lungs generates alpha radiation, which then hits living tissue. It poses a certain (quite low) risk of cancer.
That is why we have limit values for radon.
Gamma radiation can be measured directly with instruments; it gives an indication of how much radon is being formed. If the lightweight concrete is OK, there will be no gamma radiation.
IF there is gamma radiation, the radon level still varies greatly. Since it is ventilated out, ventilation varies from house to house.
In this case, it is about possible radon from blåbetong (blue-gray lightweight concrete). Not all blåbetong emits radon.
When the uranium that may be in the lightweight concrete decays, gamma radiation is generated that can be measured easily. When it decays, the gas radon is formed. Gamma radiation is considered harmless in these contexts. But if there is gamma radiation, it is known that it is uranium-containing blåbetong.
Radon in turn decays and then emits alpha radiation. Alpha radiation is dangerous (obviously depends on the concentration) when it hits living tissue. But alpha radiation does not penetrate anything; a sheet of paper is enough to stop the radiation. When it is generated in the room and hits you, it does not penetrate the outer layer of the skin, which consists of dead tissue. Therefore harmless.
BUT you breathe in the air, and the radon that gets into the lungs generates alpha radiation, which then hits living tissue. It poses a certain (quite low) risk of cancer.
That is why we have limit values for radon.
Gamma radiation can be measured directly with instruments; it gives an indication of how much radon is being formed. If the lightweight concrete is OK, there will be no gamma radiation.
IF there is gamma radiation, the radon level still varies greatly. Since it is ventilated out, ventilation varies from house to house.
was in a house thatH hempularen said:
had radon, it was solved with FTX instead of natural ventilation. But when ventilating, is "regular" air exchange enough? That is, at least 0.35 l/s/m2? Or normally, must it be more?
Hi
Can you find any information about the brand of lightweight concrete?
Siporex manufactured in Gävle or Dalby (I think it's called) was sand-based and has a low radon level. Ytong
Ytong (Yxhult) has varying radon levels depending on where the raw material was extracted. Then there are other manufacturers (Durox, Grönhögen on Öland, among others) that also have varying radon levels.
The source of this information is a book whose name I unfortunately forgot. But if you find a library, you might find it. I think it was called something like the lightweight concrete handbook.
best regards, LOB
Can you find any information about the brand of lightweight concrete?
Siporex manufactured in Gävle or Dalby (I think it's called) was sand-based and has a low radon level. Ytong
Ytong (Yxhult) has varying radon levels depending on where the raw material was extracted. Then there are other manufacturers (Durox, Grönhögen on Öland, among others) that also have varying radon levels.
The source of this information is a book whose name I unfortunately forgot. But if you find a library, you might find it. I think it was called something like the lightweight concrete handbook.
best regards, LOB
Yes, what I wrote about was how the OP can possibly investigate if there are any issues with radon from aerated concrete in the house.
IF it turns out there is, then you need to start looking at what it might cost to address. The problem there is that no one knows how much action is needed to get the levels below the limit. FTX often works but not always.
As a buyer, you then have two options: either budget for a remedy and possibly lower your offer accordingly, or walk away and keep looking.
The first house we almost bought, just over 30 years ago, was a terraced house built in the 60s. The realtor had an inspection report that he was happy to show, but he was very careful not to let us leaf through it ourselves. He held the report tightly. I asked about blue concrete. He showed that the inspector had written "frame in concrete." But he always kept his finger right before "concrete." I questioned what he was hiding. He denied hiding anything but kept his finger there. I eventually took the report by force, prying his fingers away. It said "light" where he held his finger. No deal was made.
IF it turns out there is, then you need to start looking at what it might cost to address. The problem there is that no one knows how much action is needed to get the levels below the limit. FTX often works but not always.
As a buyer, you then have two options: either budget for a remedy and possibly lower your offer accordingly, or walk away and keep looking.
The first house we almost bought, just over 30 years ago, was a terraced house built in the 60s. The realtor had an inspection report that he was happy to show, but he was very careful not to let us leaf through it ourselves. He held the report tightly. I asked about blue concrete. He showed that the inspector had written "frame in concrete." But he always kept his finger right before "concrete." I questioned what he was hiding. He denied hiding anything but kept his finger there. I eventually took the report by force, prying his fingers away. It said "light" where he held his finger. No deal was made.
In addition to what several people have written above, it's basically only smokers who are affected by cancer related to radon. So if you live in a house with radon above the limit and smoke, you should take it seriously, but if you don't smoke, the risk with radon is much less.
Blue concrete usually gives values under 1000bq/m3 otherwise soil radon is probably involved as well. As a curiosity, 1300bq/m3 is okay when working underground in the mine.
Our house was at about 300bq/m3 before we installed an FTX system. Currently conducting a measurement to see where we land. Expecting about 100bq/m3.
Our house was at about 300bq/m3 before we installed an FTX system. Currently conducting a measurement to see where we land. Expecting about 100bq/m3.
A simpler radon meter with a display allows you to quickly get an indication of whether there are elevated radon levels (and know if you need to budget for further measurement and possible actions). In advance, you can have tried handling in your current dwelling, outdoors, and so on. For example, like this one https://www.proffsmagasinet.se/mati...adonmatare/airthings-home-radonmatare-mw14910
It's quite easy to replace non-load-bearing 7cm walls when you're already planning to wallpaper and reroute electricity and what you might have in mind. In the bathroom, you might tear everything down when you redo it.
On the basement floor structure, it might say that there are 2x4 studs. Does it say screwed in? It could be worth checking if they are on top or embedded as well. Embedded studs are usually considered a risky construction.
It's quite easy to replace non-load-bearing 7cm walls when you're already planning to wallpaper and reroute electricity and what you might have in mind. In the bathroom, you might tear everything down when you redo it.
On the basement floor structure, it might say that there are 2x4 studs. Does it say screwed in? It could be worth checking if they are on top or embedded as well. Embedded studs are usually considered a risky construction.