Prestige Building Design Ltd

Best and quickest result is to remove tiles and re-tile and regrout correctly. or rake out very carefully with special tool (grout remover) and regrout. this is a longer process and sometiles damage the corners or edeges of the tiles.

This will depend on the leangth & depth of the crackin the plaster to be reparied and be it a concrete ceiliong or a plasterboared ceiling.

Depending on your price range,
top of range:tile & marble specialist.
midd range:tile magic,tile giant,tops tile,bathroom specialist
bottom of range:b&q,wicks,homebase.

My definition of a rouge trader is a tradesman with no knowledge of his trade whatsoever, emergency or a non emergency, most tradesman is 90-95% ebetable of trade. plumber/electrician who dose not have an up-to-date neci or gas safe does not mean he or she is not worthy of his trade, as a builder of 35 years experience i have come across guys who has these paper work and there's still no guarantee.
i think it's down to the amount of his or her experience.
there are 45, 50 year old tradesman that no longer on the tools but has the wealth of experience to do the job. its a consumers lottery to find that 100% tradesman,and that's at the ones top of their game.
the other end of the scale is the real cowboys with limited or little experience. a 4 year old trained man with qualifications & certificate can also guarantee your rouge trader.

Its not a good idea to paper over any existing wallpaper let alone a painted wallpaper as the finish and seems can never be tidy and will quite easily attract air bubbles and the old paper my become saturated with the new paste it begins to lift.