thermal lining paper on lining paper and ceiling?

I would strip the existing wall paper and treat the damp and mould problems first. How ever thermal wall paper does minimise damp and mould issues. But as I said above I would still strip the existing

No you have to take off the old one and then put the termal lining instead

You can't put a wallpaper until it's not dry.

Yes, you can absolutely apply thermal lining paper over existing lining paper to improve insulation in your corner room. Thermal lining paper is designed to provide additional insulation and can be installed directly on top of existing wallpaper or lining paper.

When it comes to the curved part of the ceiling, you can also extend the thermal lining paper to cover that area. However, you may encounter some challenges due to the stippled finish on the ceiling. The texture of the stippled finish may make it a bit more difficult for the thermal lining paper to adhere properly.

Here are some tips to help ensure successful installation:

1. **Prepare the Surface:** Make sure the existing lining paper and ceiling are clean, dry, and free from any dust or debris before applying the thermal lining paper. You may need to lightly sand the stippled finish to create a smoother surface for better adhesion.

2. **Use a Strong Adhesive:** Choose a high-quality adhesive specifically designed for wallpaper or lining paper installation. Make sure to apply the adhesive evenly and generously to ensure good adhesion, especially on textured surfaces.

3. **Work Carefully:** When applying the thermal lining paper, work carefully to smooth out any air bubbles or wrinkles. Use a wallpaper smoother or a clean, dry cloth to press the paper firmly against the surface.

4. **Overlap Seams:** If you need to overlap seams of the thermal lining paper, make sure to do so properly to create a seamless barrier against cold and moisture. Apply a thin layer of adhesive to the overlapping edges and press them firmly together.

5. **Allow Sufficient Drying Time:** Give the adhesive and thermal lining paper enough time to dry completely before painting or applying any additional layers. Follow the manufacturer's instructions for drying times.

By following these tips and taking care during the installation process, you should be able to successfully apply thermal lining paper over existing lining paper and extend it to cover the curved part of the ceiling in your corner room. This will help improve insulation and reduce heat loss, making the room warmer and more comfortable.