Trying to Fit Curtain Rail in Black Mortar Walls in Council House

[Knighty]

My daughter asked me to fit curtain rails in her council house which is an old house. With trepidation I attempted it but as I suspected, below a skim of some sort of plaster, was black mortar. When drilling, the mortar is so dry and powdery that the slightest movement of the drill bit will open a hole like the Grand Canyon and the plastic wall plug will not open enough to secure the curtain rail.
Does anyone know of a wall plug that is suitable for black mortar or even some sort of filler that can plug the hole and will take a wood screw ? I assume it would have to be a specialized filler.
I have scanned the DIY websites and can't see anything.
I have put the rail up, two of the four screws were fairly secure, but am waiting for the phone call that it has fallen down.
Thanks

[TheDoctor4]

Hi

This can be quite a tricky task - as you say, the more you drill the larger the holes get

I guess you have really 3 options:

- Drill out a large hole, say 12mm+ and use a product such as the following: https://www.diydoctor.org.uk/DIY-superst ... 650ml.html to fill the hole. This is a great product and once set will allow you to drill and screw into. Again, the success of this filling and its strength once set will depend on well it keys into the surrounding material. if it just crumbles and falls away again the chances are that no matter how good the filler is it will just fall out due to the material crumbling away.

- Is there a lintel above the window? If so you may be able to drill into this to fix to. We have a project will run you through the process: https://www.diydoctor.org.uk/projects/dr ... intels.htm

- If all else fails you can stick a piece of timber above the window using construction adhesive and then you can decorate it and fix the rail to this. Again, we have a project on how to do this: https://www.diydoctor.org.uk/projects/poles.htm

Hope this helps