7 day cycle is insufficient and likely to crack your screed. You should follow the procedure here. See post installation section.So some feedback from the bat cave: the decision is to go for a thermal shock using a hired-in boiler. Screed supplier is suggesting 7 day shock cycle given that no additioinal time is required for drying (usually the boiler would be hired out for a 3 week period). Thanks again for all the advice - much appreciated.