Hi everyone, hope some people can quickly help.
A friend is looking to do some networking in their home (working from home etc.) and would like to run cable up through the ceilings from various rooms in their 1930s house. When viewed from above in the attic, the ceilings look as you can see here:
Could anyone let us know what this material is, and whether there are any concerns about drilling up through it? (They're obviously concerned about asbestos etc.)
Many thanks!