Why overlaps, soakers and flashings matter in Arundel
Keeping water out at complex roof junctions is all about detail. In Arundel we face wind driven rain, occasional storm gusts from the Channel and a townscape rich with historic masonry. That mix makes correct overlaps, soakers and flashings essential for long lasting roofs that suit both modern homes and listed buildings.
Wind driven rain and historic masonry
Roofs around the River Arun often see swirling gusts and heavy showers that push water sideways into joints. Many properties have lime mortar, porous brick or flintwork. Well detailed abutments and chimneys prevent tracking and capillary action that can lead to damp patches indoors.
Getting overlaps right
Overlaps are the first line of defence. They use gravity to shed water before it ever reaches a joint. The pitch of the roof, the exposure level and the tile or slate type decide how much headlap you need.
Tiles and slates
For most clay tiles and slates, manufacturers set minimum headlaps that align with British Standards like BS 5534. As a guide, lower pitches need larger laps. In exposed parts of Arundel we often increase headlap to resist wind uplift and driven rain. Correct gauge, straight battens and consistent nail positions keep every course neat and watertight.
Valleys and ridges
Valleys concentrate water. Whether using preformed GRP, metal or lead, the laps between sections and at the top and bottom must exceed the maker’s minimums. At ridges and hips, mechanical fixing with the right overlap prevents capillary draw and keeps the line straight in strong winds.
Soakers at side abutments and dormers
Soakers are hidden metal pieces that step up each course where a roof meets a wall or dormer cheek. They stop sideways water entry and support the cover flashing above.
Step soakers and secret gutters
Individual step soakers are ideal with plain tiles and slates. Each piece tucks under the tile and turns up the wall, forming a mini dam. On low pitches or heavy exposure we may form a secret gutter to carry water safely down the junction. Correct sizing, neat welted edges and consistent steps keep the junction discreet and effective.
Flashings at chimneys, walls and rooflights
Flashings provide the visible weathering. They must be chased into the masonry, lapped over the tiling and supported correctly to avoid fatigue.
Aprons, steps, saddles and back gutters
At chimneys the classic set up is a lead back gutter behind the stack, an apron at the front and stepped side flashings with separate soakers. A properly formed lead saddle or cricket at the back splits the water and prevents pooling. At rooflights, factory flashings need clean, even laps with the surrounding tiles and a tidy, level upstand to avoid turbulence in heavy rain.
Materials and workmanship standards
Lead remains the gold standard for complex junctions. We select the right code for the task, often Code 4 for step flashings and soakers, Code 5 or 6 for aprons and back gutters depending on span and exposure. Sheets are sized to limit thermal movement, with laps, drips and fixings set to Lead Sheet Training Academy guidance. Alternatives like zinc, aluminium or high grade flashing strips can work on certain profiles when installed to the manufacturer’s instructions. Underlays, counter battens and eaves protection complement the detailing to manage any condensed moisture in line with BS 5250.
Common faults we fix
- Mortar only flashings that crack and leak
- Short headlaps on low pitches leading to capillary leaks
- One piece lead around chimneys that splits with movement
- Incorrectly sized soakers or none at all on dormers
- Blocked valleys and back gutters causing overflow
Each of these is preventable with the right overlaps, fixings and separation details.
Maintenance and surveys in Arundel
Regular checks keep junctions working. Clear valleys and back gutters, inspect chase lines for gaps, look for white staining on lead that hints at ponding and watch ceilings after storms. If you own a period cottage in the conservation area or a newer home near the river, a seasonal inspection is a smart move.
Book a roof check with Arundel Roofing
We handle sensitive heritage detailing and modern systems with the same care, always aiming for neat lines and reliable weathering. For friendly advice or to arrange a survey, speak to our local team. Find out more at Roofing Arundel and let us keep your complex junctions dry all year round.