Roof repairs in Wisbech

What the wind takes off a Wisbech roof

Almost every domestic repair in the town comes back to one of five details, and four of them sit at the edge of the roof rather than in the middle of it.

1. The ridge

The ridge is the highest line on the building, the first thing the wind meets, and on older roofs it is held down by nothing more than sand and cement. Mortar is a bedding, not a fixing. Decades of frost and thermal movement crack it, and once a ridge tile is loose at one end the wind has a handle on it. On a sheltered site that might sit there for years. Here it is usually the beginning of a sequence.

2. The verge

A gable end is the most vulnerable part of a tiled roof, because the covering has a free edge and air flowing over the gable creates lift underneath it. Verge pointing cracks out, the end tiles lose their bedding, and the next strong wind gets under the course and takes a run of tiles rather than one. Re-bedding a verge is a modest job. Making good an elevation after the verge has let go is not.

3. Slipped and lifted pantiles

Clay pantiles are characteristic of this part of the country and they are a single lap covering, hung on nibs and interlocked sideways. A pantile that has lost its clip or its nail is held by weight and interlock alone, so it can be lifted, rattled out of its channel and dropped. Concrete interlocking tiles behave the same way once their fixings corrode. On a slate roof the equivalent is nail sickness, where the nails rust through and slates start letting go across whole elevations rather than in one spot.

4. Flashings and abutments

Every junction is a joint and joints leak: chimney stacks, the wall where a single storey extension runs into the house, dormer cheeks, soil vent pipes and valley gutters between two slopes. Done properly these are lead, dressed and wedged into a chased mortar joint. Done cheaply they are a smear of cement or a strip of self adhesive tape, which on an exposed elevation buys two or three winters. If the damp is anywhere near a stack, start at chimney repairs, because stacks cause leaks out of all proportion to the area they occupy.

5. The eaves

The bottom edge is where the underlay is most likely to have perished and where wind first gets underneath the covering. On anything built before roughly the mid 1980s the underlay is bitumen felt, which goes brittle, tears and sags into the gutter where it sits holding water. None of that is visible from the ground, which is the single biggest reason quotes change once somebody is up there looking.

One breached edge is how a whole elevation goes

The argument for dealing with small roof defects quickly is a bit different here from the one you will read on a national site. It is not mainly about water, although water matters. It is about what a breach does to everything around it.

A tiled roof resists wind as a system. Each tile is held by its fixing, weighted by the courses above and sheltered by the tiles beside it. Take one out at a verge or a ridge and the wind now has an edge to get under and a route into the space beneath the covering, and the tile next along is doing a job it was never designed to do on its own. That is why a single missing pantile at a gable in October is a genuinely different problem from a single missing pantile halfway up a slope, and why a good firm treats it as more urgent than it looks.

The water argument still applies underneath all that. A hole dealt with this autumn is a tile. The same hole left through three winters is a tile, a run of batten, a stretch of underlay, a ceiling and possibly a rafter end, because the felt beneath has been taking direct rain the whole time. What the tile costs never changes. What surrounds it multiplies.

When repairing stops being sensible

• This is the third separate repair in two years on the same covering
• Tiles are coming off more than one elevation rather than from one exposed corner
• The battens are soft wherever a tile is lifted, not just at the failure
• Concrete tiles are delaminating and shedding their surface across whole slopes
• The repair needs a full scaffold on a covering that is close to the end of its life anyway

That last line is the practical test. Scaffolding is frequently the largest single item on a roofing quote and it costs the same whether it stands for a day or a fortnight. If you are paying for access on a roof you expect to re-cover within a few years, get both numbers and make the decision with them side by side. The new roof cost guide gives you the second figure and new roofs and re-roofing sets out the honest trigger points.