Hi SLR24
I have been looking through the thread on this one on and off when I have had a chance during the day but have not had time to reply. I can see that you are looking for a solution rather than additional questions. My advice would be as follows:
With regards to the asbestos regulations and the information you have been provided you are in a position, unless destructive testing takes place, that you will have to presume this is indeed an asbestos containing material.
The first port of call should not be to drill through. You will however be required to training your guys/girls on asbestos awareness course in order to comply with the following:
Regulation 10.—(1) Every employer must ensure that any employee employed by that employer is given adequate information, instruction and training where that employee—
(a)is or is liable to be exposed to asbestos, or if that employee supervises such employees, so that those employees are aware of—
(i)the properties of asbestos and its effects on health, including its interaction with smoking,
(ii)the types of products or materials likely to contain asbestos,
(iii)the operations which could result in asbestos exposure and the importance of preventive controls to minimise exposure,
(iv)safe work practices, control measures, and protective equipment,
(v)the purpose, choice, limitations, proper use and maintenance of respiratory protective equipment,
(vi)emergency procedures,
(vii)hygiene requirements,
(viii)decontamination procedures,
(ix)waste handling procedures,
(x)medical examination requirements, and
(xi)the control limit and the need for air monitoring,in order to safeguard themselves and other employees
You may have the ability to carry out the training in house or, you may need to source a local consultancy or training provider. The course should take no longer than half a day however some training courses do take 1 day. this will come down to individual preference.
With regards to the actual task, i would look into removing the tiles in one piece (this will mean detailing a comprehensive method statement as to how you will remove the tile safely without damage). You can then replace the areas requiring a tile with a non asbestos tile that you can drill through. The method statement will have to have an emergency procedure for the accidental release, the disposal of the tiles etc.
Sounds complicated but it really is not. The training will cost roughly £30.00 per persons and should be UKATA approved. The disposal of the asbestos item you will have to get a quote. The tile can be double bagged ready for collection.