We have a pitched roof (1971 house, The Netherlands) which consists of (outside to inside):
- Tiles
- 2cm PUR insulation
- 2cm wood
We asked a few companies for quotations to improve the insulation (currently Rc=0.8).
Company 1 is suggesting to add rockwool to the inside, while company 2 says that any insulation on the inside will lead to condensation issues.
Are there any options for adding insulation on the inside of the roof in this case?
Edit: picture of the roof material:
Best Answer
We had insulated the heated attic area with rock wool. After the winter, mold had formed on the wood. The reason was ice crystals between the wood and the rock wool. When thawing, the moisture has accumulated more and more on this layer. However, I don't have 2 cm PUR insulation on the outside. This certainly reduces the problem of condensation on the wood layer. It may not be easy to assess whether this will help 100%.
In our case we had newly installed all insulation with an intermediate ventilation space (2 cm) between insulation and wood. There were no problems until now for over 10 years.