How do I stop my ridge tiles coming off in high winds? 

Ridge and hip tiles being displaced in high winds is a very common issue and relates specifically to use of mortar to bed them. Although mortar is a traditional method of bedding, it has proven itself to be ineffective against issues such as:

Poor mortar mix (including wrong mix proportions) causing weakness Building movement which causes the mortar to crack Environmental conditions such as driving rain and wind that erode and dislodge the ridge from its bedding.

Unfortunately there is no easy way to retrospectively reinforce ridge and hip tiles that are already bedded. If you have had some ridges or hips dislodge then it may be sensible to have them all replaced using a dry ridge or hip system. Not only are these systems mortar and maintenance free, but they provide sufficient high level ventilation to meet building regulations.