Hello,
I just got today's shock when I was down in the boiler room rummaging around and a piece of lightweight concrete fell down when I was poking around in a vent hole. The piece is ribbed on the surface, and the fracture has a suspicious blue-gray color.
Is this the infamous blåbetong??
My boiler room consists of the old potato cellar that is converted and slightly expanded, some of the walls are built from lightweight concrete blocks that have a ribbed structure on the sides. They are painted white, which is why it hasn't been possible to see how they actually look.
My house consists of an old house from 1890 made of clay stone brick and an extension from around 1963.
The extension is, according to the seller, built of Siporex. And I think these blocks have a lighter shade than those in the boiler room... Got terrified here and thought the whole thing was made of blåbetong!!
Maybe I can claim hidden defects since the seller wrote Siporex and nothing about Ytong or blåbetong...?
I had a very thorough inspector at the time of purchase but he missed this too.
What should I do, is it just to move or what does one do???
I just got today's shock when I was down in the boiler room rummaging around and a piece of lightweight concrete fell down when I was poking around in a vent hole. The piece is ribbed on the surface, and the fracture has a suspicious blue-gray color.
Is this the infamous blåbetong??
My boiler room consists of the old potato cellar that is converted and slightly expanded, some of the walls are built from lightweight concrete blocks that have a ribbed structure on the sides. They are painted white, which is why it hasn't been possible to see how they actually look.
My house consists of an old house from 1890 made of clay stone brick and an extension from around 1963.
The extension is, according to the seller, built of Siporex. And I think these blocks have a lighter shade than those in the boiler room... Got terrified here and thought the whole thing was made of blåbetong!!
Maybe I can claim hidden defects since the seller wrote Siporex and nothing about Ytong or blåbetong...?
I had a very thorough inspector at the time of purchase but he missed this too.
What should I do, is it just to move or what does one do???
What you should not do is panic. Start by gathering facts about radon, and if you feel unsure, simply order a measurement.
http://www.stralsakerhetsmyndigheten.se/Allmanhet/Radon/
http://www.stralsakerhetsmyndigheten.se/Allmanhet/Radon/
I don't think you need to worry about blue concrete. If it is Siporex in the extension, the risk of having any radon from it is very small.
If you now have a bit of blue concrete in the boiler room, this blue concrete volume alone cannot cause radon gas levels exceeding 200 Bq/m3 for the property.
However, you definitely should conduct a long-term measurement, which everyone should do.
But now you have to wait until October 1st. You cannot conduct a long-term measurement now during the spring and summer period. The environmental office at the municipality can usually help with measurement dosimeters.
Good luck
SBR
If you now have a bit of blue concrete in the boiler room, this blue concrete volume alone cannot cause radon gas levels exceeding 200 Bq/m3 for the property.
However, you definitely should conduct a long-term measurement, which everyone should do.
But now you have to wait until October 1st. You cannot conduct a long-term measurement now during the spring and summer period. The environmental office at the municipality can usually help with measurement dosimeters.
Good luck
SBR
Take it easy and conduct a measurement, there doesn't need to be any alarming levels. The absolute highest radon levels are usually found in wooden houses with crawl spaces or "torpargrund". There are record levels of up to 10,000 bequerel.
Best regards
Best regards
Last edited:
Thank you,
feels a bit calmer after reading your posts. The boiler room has two walls clad with blåbetong, the house has a torpargrund, except under the kitchen where the boiler room is located. The torpargrund is such that there is air under the floor joists resting on a foundation wall of concrete/natural stone, but not enough to crawl in.
The house is located in Limhamn outside Malmö... I don't know if the geographical location matters for additional radon risks, apart from the building material.
One could install mechanical exhaust ventilation in the boiler room, which should remove some, right??
feels a bit calmer after reading your posts. The boiler room has two walls clad with blåbetong, the house has a torpargrund, except under the kitchen where the boiler room is located. The torpargrund is such that there is air under the floor joists resting on a foundation wall of concrete/natural stone, but not enough to crawl in.
The house is located in Limhamn outside Malmö... I don't know if the geographical location matters for additional radon risks, apart from the building material.
One could install mechanical exhaust ventilation in the boiler room, which should remove some, right??
What kind of boiler do you have there today that you use?njitnjau said:
If it's a pellet boiler or similar, it ventilates as soon as it runs.
You should only install a small fan if you have an electric boiler or similar, so you don't create negative pressure in the boiler room when you are burning.
Oh.. I will be remediating 2 houses in Limhamn next week. Against ground radon!njitnjau said:
There are some areas in Limhamn with quite a bit of ground radon!
Gejersgatan, Götgatan, Lillbacksgatan + a few more that I don't have in mind right now.
Do a measurement!
Best regards
SBR
What do you have in the boiler room? In other words, what do you heat the house with? If, for example, you heat with oil or wood/pellets, you already have a powerful exhaust unit in your boiler! Installing mechanical ventilation there then is neither necessary nor appropriate.
Moving doesn't make any sense at all! There is blue lightweight concrete in many properties in Sweden, and one shouldn't exaggerate the health risks—especially if the location is only a boiler room... Naturally, you can calmly conduct a radon measurement in the fall, as suggested. Before that, you can check your ventilation to ensure it's in reasonable balance; often, there's insufficient supply air vents in older properties.
Moving doesn't make any sense at all! There is blue lightweight concrete in many properties in Sweden, and one shouldn't exaggerate the health risks—especially if the location is only a boiler room... Naturally, you can calmly conduct a radon measurement in the fall, as suggested. Before that, you can check your ventilation to ensure it's in reasonable balance; often, there's insufficient supply air vents in older properties.
Last edited:
We conducted a radon measurement in our previous house which had a lot of Ytong. It turned out that the values were well below what could be considered harmful. However, in the basement, there were slightly high levels of ground radon. This was ventilated away. A measurement will either reassure you or provide enough facts to take action or decide to sell. I don't think you should worry right now. "He who cries over tomorrow, cries twice..."
They don't need to worry more than others - somelvis' statement is his own. I haven't seen anything to support his thesis, either in the field or in research! I would probably call it a gross generalization and moreover an incorrect one. But if somelvis can present support for his thesis, then of course I will concede...
PX-21 said:Now are all those with wooden houses and crawl spaces reassured?
Best regards
The highest levels of radon that have been measured come from radon originating from the ground. Since houses with crawl spaces and beam foundations do not have a concrete slab, they are heavily exposed to ground radon. Stone material houses have a concrete slab and are thus less exposed to ground radon. It can naturally seep in through poorly sealed floor drains and cracks in the concrete, but this can also happen in newly built houses of all building materials.
Check for example here under the question "I live in a wooden house, surely there can't be radon there?"
http://www.mrm.se/radon/?action=faq
Or here question 11. "My house is not built of blue lightweight concrete, surely there can't be radon there?"
http://www.gammadataradon.se/default.aspx?PID=37
Or here http://www.gardochtorp.se/radon-finns-overallt.aspx?article=4219
I don't mean to scare owners of houses with crawl spaces/beam foundations, but there is a general myth that lightweight concrete/Ytong is always extremely dangerous and that old charming wooden houses are the healthiest available.
It might need to be viewed a bit more nuanced, and above all, owners of wooden houses need to be informed about the record-high levels that can exist if the house stands on bedrock, gravel ridges, and even moraine. It's a shame that so many believe it's risk-free in wooden houses.
Best regards
Check for example here under the question "I live in a wooden house, surely there can't be radon there?"
http://www.mrm.se/radon/?action=faq
Or here question 11. "My house is not built of blue lightweight concrete, surely there can't be radon there?"
http://www.gammadataradon.se/default.aspx?PID=37
Or here http://www.gardochtorp.se/radon-finns-overallt.aspx?article=4219
I don't mean to scare owners of houses with crawl spaces/beam foundations, but there is a general myth that lightweight concrete/Ytong is always extremely dangerous and that old charming wooden houses are the healthiest available.
It might need to be viewed a bit more nuanced, and above all, owners of wooden houses need to be informed about the record-high levels that can exist if the house stands on bedrock, gravel ridges, and even moraine. It's a shame that so many believe it's risk-free in wooden houses.
Best regards
Yes, but what is not correct is linking it to wooden houses. It is the foundation construction in harmony with other factors (such as the nature of the ground underneath the building and the construction of any waterproofing), which determines to what extent there is a risk of radon ingress. There are, for instance, modern constructions where one can effectively radon-proof even these foundation types.
Furthermore, there is quite a large number of small houses built with basements as a foundation. In these, it is also relatively common to have construction elements made of "blå lättbetong" - in these you can see radon-affected houses, both "wooden houses" and "stone houses". However, the issue increases in cases where the mineral has been used in, for example, floor structures. Finally, there are some properties, predominantly on the west coast, where "Bohusgranit" has been used and these houses experience a radon issue precisely because they are "stone houses".
Generally, it is also easier to remedy houses without the presence of "byggradon". The results usually end up being lower than when there are lots of "blå lättbetong" in the building. It should also be noted that the increased gamma radiation found in stone houses is not present in houses without stone materials.
Furthermore, there is quite a large number of small houses built with basements as a foundation. In these, it is also relatively common to have construction elements made of "blå lättbetong" - in these you can see radon-affected houses, both "wooden houses" and "stone houses". However, the issue increases in cases where the mineral has been used in, for example, floor structures. Finally, there are some properties, predominantly on the west coast, where "Bohusgranit" has been used and these houses experience a radon issue precisely because they are "stone houses".
Generally, it is also easier to remedy houses without the presence of "byggradon". The results usually end up being lower than when there are lots of "blå lättbetong" in the building. It should also be noted that the increased gamma radiation found in stone houses is not present in houses without stone materials.
In the utility room, I have the indoor unit for my air/water heat pump and the hot water tank, so there's no burning. However, there used to be an oil furnace, which meant the situation was different with lots of air passing through the utility room. Additionally, all the vents are bricked up, if there ever were any, except for one that goes into the utility room. Furthermore, two air channels from the crawl space lead into the utility room.
Since we no longer burn anything, I'm thinking that a mechanical exhaust should be good and do the job that the furnace did previously, namely, pulling air out from the crawl space and utility room..?
Doesn't sound fun with radon in Limhamn... I live not far from Geijersgatan. Huh!!!
Since we no longer burn anything, I'm thinking that a mechanical exhaust should be good and do the job that the furnace did previously, namely, pulling air out from the crawl space and utility room..?
Doesn't sound fun with radon in Limhamn... I live not far from Geijersgatan. Huh!!!
Last edited:
I have only seen wooden houses with crawl space foundations.Humulus said:
I have never seen a house with a heavy frame (stone house) on such a foundation. They usually have a poured concrete slab as far as I know.
Hence crawl space foundation = wooden house
That foundation has been shown to have the highest radon levels.
Regards
Last edited: