Hello fellow homebuilding enthusiasts,
New construction KfW70 single-family house.
We are currently deciding whether to insulate our attic space right away and whether to install OSB boards at the same time. The carpenters don’t have a clear opinion on this.
I would like to hear some advantages and disadvantages; right now, I only see the financial aspect. Both together would cost me about 2400 € net additionally. A colleague of mine said today that he wanted to save money on his new build but now is willing to invest. He would have it done right away.
Cross-sections attached.
Looking forward to your suggestions.
New construction KfW70 single-family house.
We are currently deciding whether to insulate our attic space right away and whether to install OSB boards at the same time. The carpenters don’t have a clear opinion on this.
I would like to hear some advantages and disadvantages; right now, I only see the financial aspect. Both together would cost me about 2400 € net additionally. A colleague of mine said today that he wanted to save money on his new build but now is willing to invest. He would have it done right away.
Cross-sections attached.
Looking forward to your suggestions.
D
DerBjoern8 Oct 2014 10:09If you choose to insulate up to the attic floor instead of just the ceiling of the upper floor, the heated space will naturally increase and the surface area for heat transmission will also be larger. Therefore, you should check with your planner whether this will affect, for example, energy regulations or KfW classifications.
If the space is only going to be used for storage, you can consider whether it needs to be insulated based on what will be stored there.
Regarding OSB boards, consult your planner as well. The use of OSB boards is not without risks concerning moisture buildup and condensation problems...
If the space is only going to be used for storage, you can consider whether it needs to be insulated based on what will be stored there.
Regarding OSB boards, consult your planner as well. The use of OSB boards is not without risks concerning moisture buildup and condensation problems...
It’s not just insulation that matters; the vapor barrier is crucial. It needs to form a continuous envelope. In the sketch above, it runs along the ceiling of the upper floor.
If you can, extend it up into the attic so that
This cannot be done afterwards and is very difficult to resolve later on.
DaveS
If you can, extend it up into the attic so that
- in case of finishing the space above, it runs all the way to the gable or
- in case of future finishing, the membrane can be connected.
This cannot be done afterwards and is very difficult to resolve later on.
DaveS
D
Doc.Schnaggls8 Oct 2014 16:34Hello,
if you insulate the attic all the way up to the ridge, you should also consider that you then create a hermetically sealed space that is no longer ventilated by the usual ventilation bricks.
In our house, we had planned to insulate the roof up to the ridge in addition to the insulated ceiling of the top floor – however, we were advised against it several times.
If an insulated attic is not regularly ventilated (or connected to a mechanical ventilation system with heat recovery) can quickly develop condensation and then mold.
We decided to skip the insulation but ordered the floor to be “walkable” right away.
Best regards,
Dirk
if you insulate the attic all the way up to the ridge, you should also consider that you then create a hermetically sealed space that is no longer ventilated by the usual ventilation bricks.
In our house, we had planned to insulate the roof up to the ridge in addition to the insulated ceiling of the top floor – however, we were advised against it several times.
If an insulated attic is not regularly ventilated (or connected to a mechanical ventilation system with heat recovery) can quickly develop condensation and then mold.
We decided to skip the insulation but ordered the floor to be “walkable” right away.
Best regards,
Dirk
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