Chapter 1: Why do tiles keep slipping on our house on the high ground in Medstead?
What we find
At 180 metres and more, the wind has a long run at a Medstead roof, and the strongest suction acts at the edges: the verge, the ridge and the eaves. A tile held by gravity and one nail will lift when a gust gets underneath it, and each time it lifts it works a little looser. Over a number of winters, the nail head shifts in the batten, the tile settles out of line and the course above starts to ride up.
From the garden, look for tiles sitting at a slight angle, a gap along a gable edge or a scatter of broken fragments on the lawn after a gale. In the loft, a draught along the eaves or fine spray marks on the underside of the felt show that wind-driven rain is being forced through the laps. A roof exposed like this tends to repeat the fault until the fixings change.
What we fix
We re-lay the slipped tiles with clips on the exposed courses and stainless or galvanised nails of the right length, and check that the battens underneath are not split or rotten. The edges get extra attention. Verge tiles can be fixed with a continuous dry verge system, and the ridge can be mechanically held down rather than bedded in mortar, which matches the thinking behind BS 5534. If a tile was lost to the wind, damp felt behind it is replaced.
A repair of this sort usually takes a day. Our guide to roof tiles lifting in the wind explains the physics of uplift, and our ridge tile repairs page covers the hipped and gabled details. Reported UK prices for dry-fixing the ridge of a semi start at £900 and reach £1,600, with scaffold on top at £300 to £900 more. Your fixed quote follows the survey.