Hello.
We will be building a single-family house in 2016. Our budget is tight. Including a contingency, we have 300,000 euros available for 160 sqm (1,722 sq ft) (excluding landscaping, no basement, no carport). Our architects are currently preparing the tenders for the individual trades. As indicated in the subject, we need to decide soon on the insulation for the roof. For the thermal protection certificate according to the Energy Saving Ordinance 2014, 24 cm (9.5 inches) of mineral wool 035 was calculated for the roof. However, our architects recommend using blown-in loose-fill insulation instead. This is said to provide better protection against summer heat in particular. Since some of our rooms will have very high ceilings and extend right up to the roof, this argument could indeed be important. We are, however, concerned about the higher costs of loose-fill insulation and also worry that blown-in insulation might settle downward (pitched roof) causing a gap to form at the ridge.
What do you think? Are there any experiences regarding the costs and potential compression or settling of loose-fill insulation?
Thanks and best regards.
We will be building a single-family house in 2016. Our budget is tight. Including a contingency, we have 300,000 euros available for 160 sqm (1,722 sq ft) (excluding landscaping, no basement, no carport). Our architects are currently preparing the tenders for the individual trades. As indicated in the subject, we need to decide soon on the insulation for the roof. For the thermal protection certificate according to the Energy Saving Ordinance 2014, 24 cm (9.5 inches) of mineral wool 035 was calculated for the roof. However, our architects recommend using blown-in loose-fill insulation instead. This is said to provide better protection against summer heat in particular. Since some of our rooms will have very high ceilings and extend right up to the roof, this argument could indeed be important. We are, however, concerned about the higher costs of loose-fill insulation and also worry that blown-in insulation might settle downward (pitched roof) causing a gap to form at the ridge.
What do you think? Are there any experiences regarding the costs and potential compression or settling of loose-fill insulation?
Thanks and best regards.
K
Komposthaufen28 Apr 2016 11:25Update: Construction has now started. Exciting!
The question remains which insulation we want to use for the pitched roof. The following options are available:
Mineral wool: €2,652
Cellulose insulation: approx. €2,945
Wood fiberboards: €3,966
(prices are for the entire roof, all excluding VAT)
Our thermal protection certification works with all types of insulation.
The architect really prefers the cellulose loose-fill insulation but cannot provide any long-term experience regarding its dimensional stability (concern: possible compression). The carpenter supports the wood fiberboards, mainly due to their (allegedly) better dimensional stability, improved sound insulation properties, higher ecological quality, and better protection against summer heat.
Our bedrooms on the upper floor (children’s rooms and master bedroom) will extend up to the roof ridge. Therefore, the summer thermal protection of the insulation should not be overlooked.
Perhaps someone here has faced similar decisions and can offer some advice?
Thanks and best regards,
Fabian
The question remains which insulation we want to use for the pitched roof. The following options are available:
Mineral wool: €2,652
Cellulose insulation: approx. €2,945
Wood fiberboards: €3,966
(prices are for the entire roof, all excluding VAT)
Our thermal protection certification works with all types of insulation.
The architect really prefers the cellulose loose-fill insulation but cannot provide any long-term experience regarding its dimensional stability (concern: possible compression). The carpenter supports the wood fiberboards, mainly due to their (allegedly) better dimensional stability, improved sound insulation properties, higher ecological quality, and better protection against summer heat.
Our bedrooms on the upper floor (children’s rooms and master bedroom) will extend up to the roof ridge. Therefore, the summer thermal protection of the insulation should not be overlooked.
Perhaps someone here has faced similar decisions and can offer some advice?
Thanks and best regards,
Fabian
N
nightdancer28 Apr 2016 12:55Komposthaufen schrieb:
Update: Construction has now started. Exciting!
The question remains which insulation we want to use for the pitched roof. The following options are available:
Rock wool: €2,652
Cellulose insulation: approx. €2,945
Wood fiber boards: €3,966
(each for the entire roof, all prices excluding VAT)
Our thermal protection certificate is valid for all types of insulation.
The architect prefers cellulose loose-fill insulation but cannot provide long-term experience regarding dimensional stability (concern: possible compression). The carpenter favors the wood fiber boards, mainly due to (claimed) better dimensional stability, improved sound insulation, higher ecological quality, and better summer thermal protection.
Our bedrooms on the upper floor (children’s rooms and master bedroom) will extend up to the roof ridge. Therefore, the summer thermal protection of the insulation should not be overlooked.
Perhaps someone has faced similar questions and can offer some advice?
Thanks and regards.
FabianWithout specifying thickness and U-value, it’s just guesswork.
K
Komposthaufen28 Apr 2016 13:33Rübe1 schrieb:
Can you finally tell us the planned or already installed roof structure after almost 4 months?I overlooked your earlier question above. Sorry about that.
Here is the information from the carpenter’s scope of work specification:
"Rafter roof. The undersides of the rafters are covered with a vapor-tight OSB sheathing. The tops of the rafters are covered with an under-roof board that is vapor-permeable and windproof. Counter battens and roof battens are installed on top of the under-roof board. The thermal insulation is installed as blown-in cellulose fibers as insulation between the rafters."
nightdancer schrieb:
Without specifying thickness and U-value, it’s just guessingBlown-in insulation:
Insulation thickness approx. 220 mm (9 inches)
Thermal conductivity λ (DIN 4108): 0.038 W / m·K
or
Mineral wool:
Insulation thickness: 240 mm (9.5 inches)
Declared thermal conductivity: 0.035 W/(m·K) according to
approval Z-23.15-1468
I don’t have the offered data for wood fiber boards at hand right now.
Best regards,
Fabian
Oh wow. Are you sure you are building with an architect? This looks more like a general contractor design, considering how confusing it is.
In principle, the structure is suitable for blown-in insulation if the rafter spacing and other details are known. But why only 220 mm (9 inches) of loose fill and 240 mm (9.5 inches) of mineral wool? Either it’s a typo or...? It might be like a steam bath inside that cavity?? 😀
In principle, the structure is suitable for blown-in insulation if the rafter spacing and other details are known. But why only 220 mm (9 inches) of loose fill and 240 mm (9.5 inches) of mineral wool? Either it’s a typo or...? It might be like a steam bath inside that cavity?? 😀
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