Hello!
My partner and I are interested in this house:
http://www.hemnet.se/bostad/villa-6rum-hestra-gislaveds-kommun-lingonstigen-2-10440435
However, we stayed up all night yesterday reading about how poor the foundation/slab can be on a house from the 70s.
Should we let someone else buy this house, or is there no risk with the slab, as long as you maintain it properly, is there no danger?
What I really want to know is:
- If you maintain the slab properly, is it possible to keep it "alive" for another 45 years?
- How do you maintain a slab from the 70s?
- I know how to drain a foundation with a basement; is it the same process for a slab on grade?
- What do you do inside? Are the layers: Concrete slab and wooden floor? Or what do the layers look like? And how SHOULD it look?
And finally, is there a significant risk that this particular house might need to be completely dug up in the future and recast entirely? I've read horror stories where entire houses had to be lifted and recast... We don't want that
Additionally, what should one consider when it comes to 70s houses?
Very grateful for assistance!
My partner and I are interested in this house:
http://www.hemnet.se/bostad/villa-6rum-hestra-gislaveds-kommun-lingonstigen-2-10440435
However, we stayed up all night yesterday reading about how poor the foundation/slab can be on a house from the 70s.
Should we let someone else buy this house, or is there no risk with the slab, as long as you maintain it properly, is there no danger?
What I really want to know is:
- If you maintain the slab properly, is it possible to keep it "alive" for another 45 years?
- How do you maintain a slab from the 70s?
- I know how to drain a foundation with a basement; is it the same process for a slab on grade?
- What do you do inside? Are the layers: Concrete slab and wooden floor? Or what do the layers look like? And how SHOULD it look?
And finally, is there a significant risk that this particular house might need to be completely dug up in the future and recast entirely? I've read horror stories where entire houses had to be lifted and recast... We don't want that
Additionally, what should one consider when it comes to 70s houses?
Very grateful for assistance!
Self-builder
· Stockholm
· 8 605 posts
Relatively few houses have the latest most "secure" foundation construction, so if you buy an older house, you always take a risk.
But if the inspection doesn't point out elevated values, I wouldn't say it seems more risky to buy that house compared to anything else?
Then you always have to take care of the house, and a drainage might be in order (if it was built 45 years ago as well?)
The important thing is to do a thorough inspection, I would say.
/K
But if the inspection doesn't point out elevated values, I wouldn't say it seems more risky to buy that house compared to anything else?
Then you always have to take care of the house, and a drainage might be in order (if it was built 45 years ago as well?)
The important thing is to do a thorough inspection, I would say.
/K
I've read up a bit now.
To keep moisture away from a 70s slab, good drainage needs to be done.
- Does anyone have a good guide for draining a slab on the ground?
Good ventilation of the floor inside the house is also required, as well as ventilation inside the house that removes the damp air.
If I want underfloor heating in a house with a slab on the ground from the 70s, how do you build up the floor then?
- Does anyone have a good guide for flooring with and without underfloor heating on the aforementioned slab?
Thankful for answers and help!
To keep moisture away from a 70s slab, good drainage needs to be done.
- Does anyone have a good guide for draining a slab on the ground?
Good ventilation of the floor inside the house is also required, as well as ventilation inside the house that removes the damp air.
If I want underfloor heating in a house with a slab on the ground from the 70s, how do you build up the floor then?
- Does anyone have a good guide for flooring with and without underfloor heating on the aforementioned slab?
Thankful for answers and help!
I've read that odors can come from 70s concrete slabs, due to the use of "used" sand (whatever was available near the construction site) on the slab to "even it out," and the floating floor was laid on top of that. It might be a good idea to keep an eye on this, so lie on the floor during showings and sniff the joints. But if it hasn't started smelling in 40 years, the risk is probably quite small that it will start now.
As I see it, a slab-on-grade is one of the safest building constructions. No drainage, no surprises. (if it was poured on properly planned ground. If it hasn't cracked by now, I doubt it will start now, in my opinion
As I see it, a slab-on-grade is one of the safest building constructions. No drainage, no surprises. (if it was poured on properly planned ground. If it hasn't cracked by now, I doubt it will start now, in my opinion
Does anyone have a good guide on how the layers should be for a slab without insulation?
Is the following correct?
1. Uninsulated foundation/slab
2. Platon mat with vent. up above the skirting board. How is it done here, when you have self-leveled with electric underfloor heating?
3. Damping mat
?. (No insulation?)
4. Flooring chipboard
5. "Floor paper"
6. Floor
Is the following correct?
1. Uninsulated foundation/slab
2. Platon mat with vent. up above the skirting board. How is it done here, when you have self-leveled with electric underfloor heating?
3. Damping mat
?. (No insulation?)
4. Flooring chipboard
5. "Floor paper"
6. Floor
Are there any signs of problems today? Are there measured elevated moisture levels?
If not, there is no reason to change anything; if it has worked for 45 years, it will likely continue to work.
It's quite well-drained soil in the area, so the need for drainage may be less, but of course, drainage should be reviewed, and if it hasn't been redrained at some point, you should include that cost in your calculation. The principle for this is much the same as for basement drainage but much simpler - no hassle. The most important thing is that water from downspouts is directed away from the house.
Almost all houses have their "risk constructions," so get a good inspector with good references, and you'll feel secure in your purchase, especially if you've done your research thoroughly. For 70s houses, the risks lie in the fact that moisture from the slab (due to the construction method of the slabs) can dampen the sill, which may be embedded. I believe the risk is less given that it is likely a good and self-draining ground that the house is on. However, in combination with using impregnated sills, it sometimes resulted in the houses having a confined/unpleasant odor. So-called sick house. This is probably the most important thing for you to investigate, that there are no impregnated sills; if so, you should really consider it. For IF it were to become damp for any reason, we're talking many hundreds of thousands of SEK to fix.
We have the same risk construction with embedded sills, but they aren't impregnated, and we redid the drainage a few years ago, not because we had problems, but to be on the safe side and to avoid the sill getting damp by all means.
I have so far been hesitant to install underfloor heating in the basement where our slab is, mainly because it is virtually uninsulated and is said to pose a risk of so-called reverse moisture migration, which could risk increasing moisture in the slab. Some say the risks are exaggerated, so I'm not really sure...
Ventilation can also be a bit tricky in a 70s house. At the time, they were just starting to move from natural ventilation to different mechanical exhaust solutions, and it wasn't always optimal...
Otherwise, 70s houses are spacious and often very practical; we like ours very much.
During renovations, it's also convenient since most things are usually straight and nice, which simplifies a lot.
Good luck with your house purchase.
If not, there is no reason to change anything; if it has worked for 45 years, it will likely continue to work.
It's quite well-drained soil in the area, so the need for drainage may be less, but of course, drainage should be reviewed, and if it hasn't been redrained at some point, you should include that cost in your calculation. The principle for this is much the same as for basement drainage but much simpler - no hassle
. The most important thing is that water from downspouts is directed away from the house. Almost all houses have their "risk constructions," so get a good inspector with good references, and you'll feel secure in your purchase, especially if you've done your research thoroughly. For 70s houses, the risks lie in the fact that moisture from the slab (due to the construction method of the slabs) can dampen the sill, which may be embedded. I believe the risk is less given that it is likely a good and self-draining ground that the house is on. However, in combination with using impregnated sills, it sometimes resulted in the houses having a confined/unpleasant odor. So-called sick house. This is probably the most important thing for you to investigate, that there are no impregnated sills; if so, you should really consider it. For IF it were to become damp for any reason, we're talking many hundreds of thousands of SEK to fix.
We have the same risk construction with embedded sills, but they aren't impregnated, and we redid the drainage a few years ago, not because we had problems, but to be on the safe side and to avoid the sill getting damp by all means.
I have so far been hesitant to install underfloor heating in the basement where our slab is, mainly because it is virtually uninsulated and is said to pose a risk of so-called reverse moisture migration, which could risk increasing moisture in the slab. Some say the risks are exaggerated, so I'm not really sure...
Ventilation can also be a bit tricky in a 70s house. At the time, they were just starting to move from natural ventilation to different mechanical exhaust solutions, and it wasn't always optimal...
Otherwise, 70s houses are spacious and often very practical; we like ours very much
. During renovations, it's also convenient since most things are usually straight and nice, which simplifies a lot.
Good luck with your house purchase.
If the house has an uninsulated concrete slab directly on the ground (i.e., no basement), I would refrain from purchasing it. The problem with this construction is that the water vapor in the indoor air goes into the concrete and condenses when it becomes sufficiently cooled. This leads to the concrete becoming damp and unsuitable for combining with organic materials such as wood. This issue cannot be remedied with drainage. An uninsulated slab in a basement is usually not a problem because, firstly, the temperature is lower there, and secondly, floors are rarely built on top of the concrete.
If there are no defects in the house today, which is relatively easy to check, it is proven that the construction works on the house.
If no defects have occurred in 40 years and if the house is maintained in the future, there is no reason to refrain from a purchase. It is significantly more risky to buy a modern house where potential shortcuts or construction errors have not yet had the chance to manifest.
If no defects have occurred in 40 years and if the house is maintained in the future, there is no reason to refrain from a purchase. It is significantly more risky to buy a modern house where potential shortcuts or construction errors have not yet had the chance to manifest.
Now, I'm no expert but have a house with uninsulated slab. I've replaced all the floors and haven't seen any signs of moisture from the slab anywhere. However, there are houses in the area that have basements. 100% of these have moisture in their basements, varying amounts and risks. Would never switch to a house with uninsulated basements.justusandersson said:
I would also not build a house with an uninsulated basement. If you treat the basement as a residential floor, you may encounter problems that make others seem minor. An uninsulated slab on grade is a risky construction, but if you ensure that no wood has direct contact with the concrete or traps moisture, it can last for ages. However, the problem remains that the construction is limiting, for example, when it comes to choosing flooring material. It is also not reasonable for a homeowner to need to be an expert in building physics. The house should also be sellable. Since the question is whether to buy or not, my advice is: Do not buy.
I just have a follow-up question. If you want to buy a house with a few years under its belt at a reasonable price, which construction would you choose?justusandersson said:
Most houses built between 1950 and 1970 are interesting. They mostly have basements, but if you consider the basements as basements, there are usually no major problems. Houses before 1960 almost always have higher quality in terms of timber quality, windows, etc. Concrete tiles were uncommon. The colors were better. The insulation standard, on the other hand, remained unchanged between 1950 and 1975.
If you look, for example, at what is required to win in a dispute, it essentially requires that the homeowner needs to have the knowledge of a structural engineer. The duty of investigation is extensive, and for most people, it means that you need to seek help to manage it.justusandersson said:
If you are not prepared to learn as much as possible about the house you are about to buy, which is often the biggest transaction you make in life, you are taking great risks. I therefore think TS is absolutely right to ask questions here to be able to make an informed decision.
If you take care to fulfill your duty of investigation and engage in the inspection, you can make a well-grounded decision.
There are many thousands of houses with similar constructions that do not have any problems. Just because it is a risk construction does not automatically mean it is a problem in the particular house. Regardless of which house you are looking at, there are questionable constructions; the problem is that it often takes several years before it shows. That is precisely why I argue that it is much safer to buy a house that is older than a newer one.
Just read about this poor person in Hammarby Sjöstad...mexitegel said:
http://www.aftonbladet.se/nyheter/article23973258.ab
I have acquaintances who have lived there and in Sickla Strand. It seems to have been problem-ridden from move-in, poorly built, paint peeling, moisture damage, missing compression rings causing water damage of Niagara proportions...
So new and fancy is probably no guarantee as stated, rather the opposite apparently. Old and well-tested is probably not wrong, but at the same time, there is much that you KNOW requires maintenance and repair.
Without being particularly knowledgeable about recent building practices, it seems as mexitegel wrote up to and including the 60s were "simple" constructions that may not be so energy-efficient but "safe." When they started with gypsum, plastic film, fiberglass, roofs without solid sheathing, cast-in pressure-treated studs, plastic mats, asbestos here and there, it feels like there CAN be serious problems - at the same time, many 70s houses appear to function just fine. But those that DO have problems should probably be avoided?