Dear forum members, 13 years after my last roof rafter insulation and drywall installation, I have a few brief questions about whether there have been any updates in terms of methods or materials.
A room of about 65 sqm (700 sq ft) above a garage is being converted into living space. The ceiling of the garage has been insulated with 160 mm (6.3 inches) of solid thermal insulation, and the heating will be done with underfloor heating and a heat pump. The carpenter raised the roof structure by about 1 meter (3.3 ft) and constructed the walls using timber frame construction. These walls are already plastered on the outside.
The timber stud walls and rafters are 190 mm (7.5 inches) wide. The carpenter advised me to use 200 mm (7.9 inches) of compressed insulation, meaning that the insulation fully fills the cavity and there is no ventilation gap at the rafters as I had previously learned. On the outside, below the roof tiles, there is a suitable moisture protection membrane.
1.) Should I work with or without ventilation (meaning 180 mm (7.1 inches) insulation at the rafters instead of 200 mm (7.9 inches), and the walls fully filled)?
2.) Last time, although it was about twice as expensive, I did not use a vapor barrier foil but a “climate membrane” that is somewhat vapor permeable (looks like packing paper) and is supposed to improve indoor air quality. Is this still common practice today or permitted under current thermal insulation regulations, or is it now standard to use foil?
3.) I will also do the drywall installation myself, including the finishing around the roof windows. Last time, I did not use drywall tape when filling the joints and did not get any cracks on the drywall anywhere in the house. Are drywall tapes absolutely necessary (and therefore a third finishing coat)?
4.) Last time, I glued foam strips between the rafters and drywall to reduce tension and cracks. Unfortunately, these strips are very difficult to remove or cover with acrylic. Is this still recommended today?
Thank you very much for your help. For example, I have noticed that quite a bit has changed regarding floor installation, and I want to make sure I do everything correctly with the drywall and insulation as well.
Best regards from Andechs
Michael
A room of about 65 sqm (700 sq ft) above a garage is being converted into living space. The ceiling of the garage has been insulated with 160 mm (6.3 inches) of solid thermal insulation, and the heating will be done with underfloor heating and a heat pump. The carpenter raised the roof structure by about 1 meter (3.3 ft) and constructed the walls using timber frame construction. These walls are already plastered on the outside.
The timber stud walls and rafters are 190 mm (7.5 inches) wide. The carpenter advised me to use 200 mm (7.9 inches) of compressed insulation, meaning that the insulation fully fills the cavity and there is no ventilation gap at the rafters as I had previously learned. On the outside, below the roof tiles, there is a suitable moisture protection membrane.
1.) Should I work with or without ventilation (meaning 180 mm (7.1 inches) insulation at the rafters instead of 200 mm (7.9 inches), and the walls fully filled)?
2.) Last time, although it was about twice as expensive, I did not use a vapor barrier foil but a “climate membrane” that is somewhat vapor permeable (looks like packing paper) and is supposed to improve indoor air quality. Is this still common practice today or permitted under current thermal insulation regulations, or is it now standard to use foil?
3.) I will also do the drywall installation myself, including the finishing around the roof windows. Last time, I did not use drywall tape when filling the joints and did not get any cracks on the drywall anywhere in the house. Are drywall tapes absolutely necessary (and therefore a third finishing coat)?
4.) Last time, I glued foam strips between the rafters and drywall to reduce tension and cracks. Unfortunately, these strips are very difficult to remove or cover with acrylic. Is this still recommended today?
Thank you very much for your help. For example, I have noticed that quite a bit has changed regarding floor installation, and I want to make sure I do everything correctly with the drywall and insulation as well.
Best regards from Andechs
Michael
Good morning! So far about 100 views and no replies yet? If this is about introductions, I have actually been active here for over 10 years but registered a new account due to a long period of inactivity, as I no longer had access to my old data.
Looking forward to any information.
Cheers
recycler (Michael)
Looking forward to any information.
Cheers
recycler (Michael)
B
borderpuschl15 Jun 2018 10:25I can only tell you how I did it in our case.
1.) I fully filled the cavity insulation between the rafters, but it depends on what you have on your rafters (wood fiber insulation boards, planks, roofing underlay). Usually, you use the exact thickness for insulation because compressing it (in your case 10mm (0.4 inches)) reduces the thermal conductivity (WLG). However, I don’t think 10mm is too critical.
2.) Below that, a vapor control membrane (e.g., siga Majpell).
3.) When applying filler compound, I wouldn’t skip the joint reinforcement tape for timber studs, like in your additional storey. This depends on the system and the type of boards used, such as fiberglass or paper tape.
4.) I don’t quite understand the purpose here. Foam is usually only applied in between as a sound decoupling layer.
Hope this helps a bit, but maybe a professional will chime in.
1.) I fully filled the cavity insulation between the rafters, but it depends on what you have on your rafters (wood fiber insulation boards, planks, roofing underlay). Usually, you use the exact thickness for insulation because compressing it (in your case 10mm (0.4 inches)) reduces the thermal conductivity (WLG). However, I don’t think 10mm is too critical.
2.) Below that, a vapor control membrane (e.g., siga Majpell).
3.) When applying filler compound, I wouldn’t skip the joint reinforcement tape for timber studs, like in your additional storey. This depends on the system and the type of boards used, such as fiberglass or paper tape.
4.) I don’t quite understand the purpose here. Foam is usually only applied in between as a sound decoupling layer.
Hope this helps a bit, but maybe a professional will chime in.
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