I have visted this property to inspect the roof, please find my recommendations below -
1. To prevent further damage to the chimney and to ensure that it is water tight I recommend that the concrete flauncing on top of the chimney is replaced. The mortar joints between the brickwork should then be ground out to a depth no less than 20mm so that the brickwork can be repointed using a new strong mortar. The stepped lead flashing should be repositioned and secured into place before it is sealed using a flexible lead sealant.
If the chimney pots are no longer in use I recommend that they are removed before the chimney is re-flaunced so the flues can be capped off and then vented.
2. I recommend the damaged tiles are replaced.
3. To ensure that the guttering is flowing correctly I recommend that the guttering is cleared out and sealed where required.
4. To ensure that the brick work next to the bathroom window is water tight and to prevent further damaged to the masonry I recommend that the area of brickwork next to the window is repointed.
5. To ensure the joint between the bay window roof and the brickwork at the front of the property is water tight I recommend that the the flashing on the flat roof is sealed using a suitable roofing sealant. .
For more details and photos regarding the recommendations I have made please see below -
1. The chimney would benefit from have maintenance work carried out to it. The concrete flauncing on top of the chimney has completely corroded away. Having a good concrete flaunce on top of the chimney is an essential part of the chimney, it is the job of the flauncing to direct water away from the top of the chimney. When the flauncing becomes comprised moisture can find its way into the brickwork below damaging mortar and bricks. Poor flauncing can also lead to water getting down the chimney flue which can lead to penetrating damp on the chimney breast inside the property. The pointing between the brickwork is very soft and missing in many places, The mortar joints between brickwork form a water tight seal between the bricks, once this seal becomes compromised moisture can find its way into the brick joints eventually causing damaged to the bricks and even penetrating damp inside the property. The damaging effects of weathering to brickwork happens at a steadily increasing rate as more and more vulnerable areas of pointing are exposed. The stepped flashing at the bottom of the chimney has fallen out of position leaving the joint between the chimneys brickwork and the roof vulnerable to penetrating damp. There are 4 open chimney pots on top of this chimney, Open chimney pots on top of unused flues can often result in penetrating damp on the chimney breast inside the property. Rain water can find its way down the open pots saturating the bricks inside the chimney flue, the force of capillary action can then draw the moisture from this saturated bricks work to the dry internal brick work on the chimney breast which can create damp patches.
2. Around the roof there are roughly 50 shale tiles, as the tiles get old moisture finds its way into any small cracks or holes within the tiles, during freezing conditions the trapped moisture expands breaking parts of the roofing tiles off.
3. The guttering around the property is heavily soiled with roof debris which will be slowing down the flow rate of the guttering causing them to work inefficiently.
4. At the front of the property next to the first floor bathroom window the mortar joints within the brickwork is very soft and missing in places.
5. Above the ground floor bay window the felt roof is missing the sealant that seals the joint where the felt laps into the brickwork, without this sealant it is possible for water that runs down the brickwork to get behind the felt which can lead to penetrating damp.
I hope that my report and quotations are to your satisfaction.