Hello everyone,
About two years ago, I bought an old house built in 1964 and completely renovated it. We moved in about 1.5 years ago. Now, I would like to insulate the ceiling of the top floor.
The roof consists of roof tiles, roofing felt, and wooden boarding – so it is completely uninsulated. Installing insulation between the rafters does not really make sense because I cannot convert the attic anyway. The height would only allow for a 1.4 m (4.6 ft) wide strip where you can stand upright. So unfortunately, that’s not really worthwhile.
My plan is to insulate the ceiling with 160 mm (6.3 inches) thick glass wool. A few very light items will still be stored up there, so I will lay down some wooden boards to stack the few light things on.
Cost-wise, this is the cheapest option, and I think it will make a noticeable difference in my old house.
What I don’t know is whether I need a vapor barrier or vapor retarder between the floor and the insulation. Can anyone tell me?
The ceiling is made of reinforced concrete, and there is even a few centimeters of screed on top. The apartment below has Heraklith boards on the underside. So, the layers from bottom to top are:
Plaster
Heraklith board (approx. 4 cm (1.6 inches))
Reinforced concrete slab
Screed
Then insulation with or without a vapor barrier/retarder in between.
My second question is: There is a door leading to the attic that opens inward. This means I cannot install insulation in the door’s swing area. Will this cause any problems?
So, hopefully someone can answer these two questions.
The total cost will be about 700€. I think (hope) this will definitely pay off within a few years.
Thanks in advance.
EDIT:
Oh yes, maybe one more small question: Does it make a big difference if I use 140 mm (5.5 inches) or 160 mm (6.3 inches) insulation? The extra cost would be about 70€.
Best regards,
Specki
About two years ago, I bought an old house built in 1964 and completely renovated it. We moved in about 1.5 years ago. Now, I would like to insulate the ceiling of the top floor.
The roof consists of roof tiles, roofing felt, and wooden boarding – so it is completely uninsulated. Installing insulation between the rafters does not really make sense because I cannot convert the attic anyway. The height would only allow for a 1.4 m (4.6 ft) wide strip where you can stand upright. So unfortunately, that’s not really worthwhile.
My plan is to insulate the ceiling with 160 mm (6.3 inches) thick glass wool. A few very light items will still be stored up there, so I will lay down some wooden boards to stack the few light things on.
Cost-wise, this is the cheapest option, and I think it will make a noticeable difference in my old house.
What I don’t know is whether I need a vapor barrier or vapor retarder between the floor and the insulation. Can anyone tell me?
The ceiling is made of reinforced concrete, and there is even a few centimeters of screed on top. The apartment below has Heraklith boards on the underside. So, the layers from bottom to top are:
Plaster
Heraklith board (approx. 4 cm (1.6 inches))
Reinforced concrete slab
Screed
Then insulation with or without a vapor barrier/retarder in between.
My second question is: There is a door leading to the attic that opens inward. This means I cannot install insulation in the door’s swing area. Will this cause any problems?
So, hopefully someone can answer these two questions.
The total cost will be about 700€. I think (hope) this will definitely pay off within a few years.
Thanks in advance.
EDIT:
Oh yes, maybe one more small question: Does it make a big difference if I use 140 mm (5.5 inches) or 160 mm (6.3 inches) insulation? The extra cost would be about 70€.
Best regards,
Specki
G
garfunkel21 Nov 2017 22:30Was the gas and wood used solely to generate heat for heating?
In our case, that is not true, so it’s difficult for me to determine how much is actually needed just for heating.
I can only calculate an average over a few years to know if such a measure was truly worthwhile.
Additionally, some winters are colder and longer than others.
In the end, I find it quite difficult to pinpoint the exact starting point or even when that might have been.
In our case, that is not true, so it’s difficult for me to determine how much is actually needed just for heating.
I can only calculate an average over a few years to know if such a measure was truly worthwhile.
Additionally, some winters are colder and longer than others.
In the end, I find it quite difficult to pinpoint the exact starting point or even when that might have been.
Wood only for heating (a wood stove in one apartment, a wood-burning cooker in another), gas of course for heating plus domestic hot water.
I see it similarly to you. You can’t determine it exactly, only estimate it more or less accurately. Too many factors come into play—ventilation habits, room temperature, etc.
But I think it will pay off over a few years. I’ll see for myself eventually. We’ve only been living in the house for 1.5 years (about 18 months)... I’ll just watch how things develop.
740 euros (€) is definitely not such a large amount that it wouldn’t be worth trying. 😉
Best regards
Specki
I see it similarly to you. You can’t determine it exactly, only estimate it more or less accurately. Too many factors come into play—ventilation habits, room temperature, etc.
But I think it will pay off over a few years. I’ll see for myself eventually. We’ve only been living in the house for 1.5 years (about 18 months)... I’ll just watch how things develop.
740 euros (€) is definitely not such a large amount that it wouldn’t be worth trying. 😉
Best regards
Specki
I’ve just insulated the top floor ceiling as well, with a similar ceiling structure, but I’m using the attic as a storage space for all sorts of things.
Therefore, I used a combination of walkable EPS boards with OSB on top and mineral wool.
The effect is definitely noticeable; the house is much warmer with the same heating, or the heating can be turned down.
It pays off quite quickly— in very old houses like ours, you can roughly save about one-third of the heating costs by properly insulating the top floor ceiling compared to leaving it uninsulated. The added comfort, hopefully also in summer, is an extra bonus 🙂
Therefore, I used a combination of walkable EPS boards with OSB on top and mineral wool.
The effect is definitely noticeable; the house is much warmer with the same heating, or the heating can be turned down.
It pays off quite quickly— in very old houses like ours, you can roughly save about one-third of the heating costs by properly insulating the top floor ceiling compared to leaving it uninsulated. The added comfort, hopefully also in summer, is an extra bonus 🙂
So, I have now installed about three-quarters of the area with 180 mm (7 inches) insulation. And yes, I can feel the difference. Not so much in the back rooms, since I have electronic thermostats there, which probably just run a bit less. But in the front living room/kitchen, I notice that I need to add less wood to the stove to maintain our temperature consistently.
I’m curious to see the overall impact on gas costs. The wood consumption has definitely decreased 🙂
The last quarter will be installed next week. Unfortunately, there’s still quite a bit of stuff up there that needs to be relocated first....
Regards
Specki
I’m curious to see the overall impact on gas costs. The wood consumption has definitely decreased 🙂
The last quarter will be installed next week. Unfortunately, there’s still quite a bit of stuff up there that needs to be relocated first....
Regards
Specki
K
Knallkörper2 Dec 2017 08:38One aspect hasn’t been addressed enough here. You have a fully boarded roof with roofing felt, which in our region is called a Harz-style underlay. This is vapor-tight. At the same time, your attic becomes colder due to the insulation. This increases the risk of condensation forming. Therefore, it is important that the attic door closes relatively airtight, and I would also take a closer look at the ventilation of the roof space.
You might also find that the attic door becomes damp on the warm side, as it is probably not insulated.
You might also find that the attic door becomes damp on the warm side, as it is probably not insulated.
Knallkörper schrieb:
One aspect hasn’t been fully addressed here. You have a fully boarded roof with roofing felt, which is called a Harz-type underlay here. It is vapor-tight. At the same time, your attic becomes colder due to the insulation. This increases the risk of condensation forming. Therefore, it is important that the attic door seals relatively airtight, and I would also take a close look at the ventilation of the attic space.
It could also happen that the door to the attic becomes damp on the warm side, which is probably not insulated.Yes, the roof is fully boarded with roofing felt, but with all the openings for ventilation and otherwise, it is not airtight in the slightest. When it is windy outside, the wind whistles through quite strongly. Basically, the temperature under the roof is almost always close to the outside temperature, except in summer when the sun heats the area significantly, making it noticeably warmer there. So there is always sufficient air exchange with the outside. Also, the attic doesn’t actually get much colder now since the temperature there was close to outside temperature anyway.
I can only repeat once more: we already feel the insulation noticeably in the front area where we heat with wood!
Regards
Specki
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