Roof insulation, insulating the roof...

Hello

we want to insulate our roof ourselves. Now we have some questions.

1. Which materials are needed or how is the roof structure (from outside to inside)?

2. Which insulation wool should be used if you want to set up a room up there later? There are different thicknesses and also some with and without aluminum foil on the back.

3. How much did you approximately pay? We need to insulate 223m² (roof area to be insulated).

Best regards

Hello Sebastian,

how the structure of a roof should look depends on one hand on the preferences of the builder himself and on the other hand on the associated costs. If the builder is more ecologically oriented, a different structure is chosen (possibly Isofloc as insulation) than if he prefers a cost-effective solution. Another possibility would be the above-rafter insulation with a continuous insulation layer and visible rafters on the inside, which is also more expensive than the standard solution.

For self-construction, I would most likely recommend a standard solution that is relatively easy to install and promises a high insulation value. This structure has also been used by most of my builders. The structure from outside to inside:

1. Roof tiles, better than concrete roof tiles
2. Roof battens 3/5
3. Counter battens 3/5
4. Diffusion-open underlay membrane
5. Rafters according to statics (usually 8/16) with glass wool or mineral wool insulation in between, e.g., 16.0 cm clamp fleece
6. Cross battens 4/6 with 4.0 cm insulation in between
7. Vapor barrier foil, here it is urgent to ensure tightness between each other and to all adjacent components (sealing)! Otherwise, there is a risk of mold formation.
8. Rafter battens 2.4/4.8 cm or similar as support battens for
9. Gypsum board 1.25 cm
10. Wallpaper of your choice

This roofing structure has an insulation thickness of 20.0 cm. If possible, equip roof windows on the south side with a roller shutter. In the area of the collar beams/clamps, rough-sawn boards with a thickness of 2.2 cm are installed instead of items 1-4.

If you go to your building materials dealer with this information and can specify the area to be produced, he will certainly be able to give you a concrete offer for the materials to be supplied. Then you will definitely know how much the material will cost.

Hopefully, this has helped you enough.

Hey Danton

Thank you very much for your great contribution! That helped me a lot!

All I can say is, I have no further questions


THANK YOU!

Hello Sebastian,

I am a bit surprised that no one has come forward so far to answer your question(s).

In my opinion, this is mainly due to the way you have phrased your question.

In a time when "being stingy is still cool," no one is likely to easily tell you that a loft conversion is not only one of the "difficult" construction tasks but also quite expensive.

At least if the work is to be properly planned, carried out, and inspected.
This is important because there is a high probability that public building law will be affected.

This primarily concerns compliance with the state building code and the energy saving ordinance.

Providing a (even only rough) price for your energy renovation case is hardly possible given the rather sparse information provided here.

My advice: Find a smart building energy consultant and commission them for an on-site consultation.
Pay particular attention to details such as thermal bridges and airtightness to obtain as comprehensive and future-proof an actual assessment as possible for the energy upgrading of your house.

From this, it can then be derived which coordinated individual measures make sense and what cost range can be expected.
In this context, advice on possible claims for funding is also not insignificant...

Kind regards from Erfurt
KPS

Hello KPS

On the one hand, my question is already exactly 6 months old, and on the other hand, the answer from Danton was actually sufficient for me. You can't say that no one is responding to my questions, since there is already an answer.

Whether the roof conversion is among the rather expensive trades ... sure, it costs something, but nothing is for free. If you have always been careful and thoughtful with the financing, I think that shouldn't be a problem either ;o)

Now I wish you a Merry Christmas and a Happy New Year!

Hello home builder,

if it really is to be an exposed rafter roof structure, it will probably only work with an insulated roofing...

The avoidance of thermal bridges can thus undoubtedly be reliably achieved.
However, the chosen variant can be expected to have higher costs as well as worse sound insulation values compared to insulation between the rafters.

Possible alternative variants (for sound and summer thermal protection in connection with the respective prices) can certainly be shown by the planner.

Best regards
KPS