Roof insulation polyurethane PU rigid foam 100mm thick

But then she has to have everything done, including the insulation between the rafters. Doing it yourself ends up costing around 1200-1500 euros. The work is manageable for laypeople, but not completely easy. Sealing the foil can be a bit tricky. It has to be airtight. Instead of a normal vapor barrier, we glued on a climate membrane that lets air through when warm, but closes when cold. The point is that moisture that may have penetrated the glass wool can dry out when warm. Does it work? Let's hope so. Our insulation project was completed in two solid days of about 10 hours each, working as a team of two. Consumption was 100 sqm of wool, 100 sqm of foil, four rolls of Sigacrall or similar, 240 m of formwork boards, 25 m of roof battens, three boxes of screws, four cartridges of foil adhesive. Just as a reference.

That is not correct. The KfW consultant only confirms the execution, which must be professional. EL materials can also be applied for. Including everything related to the measure.

Thank you, learned something new. K.

So insulating a roof is, in my opinion, not quite as much of a science as it is made out to be here. Thermal insulation is achieved with an insulation layer, whether it is above, between, or below the rafters is pretty much irrelevant. For existing buildings, a U-value of 0.24 applies. That is quickly achieved. Sound insulation and a usable phase shift (and thus heat protection) can only be achieved through mass. If the interior space allows it, for example double OSB + double drywall or clay boards, the heavier the better. What do the roofers want for the above-rafter insulation? As has been said here several times, insulation between rafters is relatively easy and also inexpensive to do yourself. Sure, when gluing the foil, careful work is required, but without time pressure, it’s not rocket science.

Man man man.
It is already bitter how taken for granted "we" deal with the tiresome fact that, for example, roofing companies at the end of the day have no clue about insulation, heat protection, soundproofing and recommend something to the customer that later turns out to be absolutely bad.

The solution is then supposed to be to insert an architect who then gives the concrete instruction to the roofer and who then carries out the work according to the specifications?!

Well, then I don’t need a specialist company! Then you can also take the supposedly so naughty naughty and bad foreign craftsmen. (For the snowflakes: No one is naughty and foreigners also do great work!)

And everyone just has money lying around here somewhere? Just quickly an architect because craftsmen have no idea about their subject... Bitter. Really very bitter.

I will soon have my roof redone as well and then the topic of thermal/heat protection is also current.
But when I read what is written here, I will probably do it myself again or with "MyHammer" craftsmen.

Unfortunately, this applies not only to roofers. Also to heating technicians or automotive mechanics. The same old routine is enough. A professional discussion often does not take place. Unfortunately. So: do it yourself (man or woman).