ᐅ Insulation of the top-floor ceiling, walkable without a vapor retarder
Created on: 15 Mar 2020 14:14
S
Schaffe123S
Schaffe12315 Mar 2020 14:14Hello everyone,
since I have already received help here before, I need a tip or confirmation again.
Between the attic rafters (11-12cm (4.3-4.7 inches)), boards are fixed in the middle.
On top of them, there is a solid, stone-like loose fill (5-6cm (2-2.4 inches): slag, volcanic rock, or whatever...).
Now I want to add insulation about 16cm (6.3 inches) thick, and the floor should later be walkable for storage purposes.
Because the “slag” is very sharp-edged and some electrical cables are laid on the floor, I cannot/will not use a vapor barrier.
Here is my plan:
- Screw three layers of timber beams (60x60mm (2.4x2.4 inches), larger ones are too bulky) onto the floor in a cross pattern
- Fill with perlite loose fill up to 16cm (6.3 inches) height
- Tongue and groove boarding for walkability with a gap of 1-2cm (0.4-0.8 inches) each for ventilation (Are gaps necessary? They don’t look nice, but it will only be used for storage)
This should allow any moisture that might develop to be carried away, since the attic is generally ventilated.
According to the U-value calculator, this is acceptable, but I would like confirmation whether this really works or if there is a simpler way (the timber beams are heavy).
Attached is the calculation.
Thank you in advance!
Regards
since I have already received help here before, I need a tip or confirmation again.
Between the attic rafters (11-12cm (4.3-4.7 inches)), boards are fixed in the middle.
On top of them, there is a solid, stone-like loose fill (5-6cm (2-2.4 inches): slag, volcanic rock, or whatever...).
Now I want to add insulation about 16cm (6.3 inches) thick, and the floor should later be walkable for storage purposes.
Because the “slag” is very sharp-edged and some electrical cables are laid on the floor, I cannot/will not use a vapor barrier.
Here is my plan:
- Screw three layers of timber beams (60x60mm (2.4x2.4 inches), larger ones are too bulky) onto the floor in a cross pattern
- Fill with perlite loose fill up to 16cm (6.3 inches) height
- Tongue and groove boarding for walkability with a gap of 1-2cm (0.4-0.8 inches) each for ventilation (Are gaps necessary? They don’t look nice, but it will only be used for storage)
This should allow any moisture that might develop to be carried away, since the attic is generally ventilated.
According to the U-value calculator, this is acceptable, but I would like confirmation whether this really works or if there is a simpler way (the timber beams are heavy).
Attached is the calculation.
Thank you in advance!
Regards