I need to replace a deteriorated cement fillet roof tile bedding above the barge boards on my bungalow as it is cracked and has fallen out in parts. I am told that it should be replaced (pointed?) with a fibre cement.which includes a retarder. Q: What is fibre cement? and can anyone advise me please as to the retarder.
Since the barge boards are rotten in places should I replace them with UPVC and is it a big job? Tom