Caerphilly & Blaenau Gwent · CF82
We repair, re-dash and clean pebble dash on Ystrad Mynach terraces, semis and estate homes, with repairs suited to wet Rhymney Valley weather.
Ystrad Mynach lies in the Rhymney Valley, where houses built for mining families sit alongside newer estates and modern homes. Pebble dash runs through all of it: on the end walls of terraces, across the fronts of council houses and on many private homes built in the decades after the war.
The valley setting brings plenty of rain and, in winter, frosts that work into any crack. That combination is hard on dash. Water gets behind the coating, freezes, expands and loosens it from the wall, and over a few winters a small crack can become a bulging, hollow section.
We carry out crack repairs, matched patching, cleaning, painting, full re-dashing and re-rendering across Ystrad Mynach and the surrounding villages. With decades of experience in home improvement and repair behind us, we can tell quickly whether a wall needs a light touch or a bigger job, and we explain our findings clearly.
Like much of the Rhymney Valley, Ystrad Mynach grew around the coal industry, and the oldest housing reflects that: stone and brick terraces strung along the valley floor and up its sides. Many were dashed in later years to cover weathered stone, hide old repairs or keep out damp. Through the middle of the twentieth century, council estates and semis were added, frequently finished in dash from the start.
The weather in this part of the valley is wetter than on the coast and often colder too. Hills on either side channel rain through, and some streets get little winter sun. As a result we commonly see:
On older terraced houses with solid walls, we pay attention to breathability, choosing materials that let moisture escape rather than sealing it in. On cavity-wall estate homes the priorities are often different, so we assess each house individually before deciding on a repair method.
Most calls start with a crack or a bulge. Our crack repair work involves raking out, checking the surrounding render and filling with a compatible mix and matched aggregate. If tapping shows the coat has come away more widely, we will suggest cutting out and re-dashing the affected area.
For walls that are sound but stained and tired, pebble dash cleaning using a gentle soft-wash can make a real difference. When the whole house is past patching, full re-dashing gives a uniform, weathertight finish and a chance to choose a new colour of stone.
Good to know
Shaded walls in the valley stay damp and grow algae and moss. We can soft-wash the dash to remove growth and treat it to slow regrowth. It is also worth checking that gutters, downpipes and ground levels are not keeping the wall wetter than it needs to be.
We try to. On valley streets where houses were dashed at similar times, there is often a common aggregate that gives us a starting point. Weathering varies, so we test samples on your wall. If you are re-dashing the whole front, we can choose a stone that sits comfortably alongside the neighbours.
Many older terraces here have solid stone or brick walls, which work best when moisture can escape. A hard, impermeable coating can trap damp. We check how your house is built and recommend renders and paints that suit it, which on older walls usually means vapour-permeable options.
We look at the street during our visit, noting where a scaffold could stand, parking for the van and how to keep the pavement usable for neighbours. Where scaffold has to go on the public footway, the scaffolding firm will usually need a licence from the council, which we allow time for.
Late spring to early autumn is usually best. Render needs dry weather and temperatures above about 5°C to cure, and valley winters are often cold and wet. Getting your survey done in winter or early spring means the job can be booked for the first reliable spell of good weather.
Services
Every service below is available in Ystrad Mynach and the surrounding area. Tap one for the full details.
We begin by looking at all the walls of your home, noting cracks, bulges, staining and previous repairs. Tapping across the dash shows us where it has lost its bond. We also check gutters, sills and downpipes, since leaks often play a part in valley damp problems, and bring aggregate samples if you want a matched repair.
We then agree access, any scaffolding, parking and a weather window. On site we protect paths, gardens and windows, keep the work area tidy and clear away all waste when we finish. To arrange a survey, call 07565 147 170 or send us the contact form.
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Case studies
A painted 1930s semi with cracks running from the front window corners and a damp patch inside. We traced the cause, repaired the cracks and repainted the front elevation.
Typical job exampleRead the case study
A terraced house facing Swansea Bay with hollow render across most of the front. Patching would not have lasted, so we stripped and re-dashed the elevation to match neighbours.
Typical job exampleRead the case study
A post-war semi with several blown areas around pipes and below sills. We patched them using a blend of aggregates sampled to match the existing natural dash.
Typical job exampleRead the case studyFAQs
Each quote is based on a survey. We look at the size of the area, how much render is loose, wall height, access and scaffolding, and the finish you want. Repairs to a single crack are a very different job from re-dashing a whole house, so we always give a written quote after seeing it.
We cannot promise an invisible repair on old dash, as the existing stone has weathered and the original may no longer be available. We source the closest aggregate and test samples on the wall first. If a visible difference is likely, we will say so and discuss painting or re-dashing the whole elevation.
Sometimes, but not always. Removal can damage the stone or brick beneath, and the wall will need a new finish afterwards. On older terraces the masonry under the dash may be in poor condition. We survey first and can try a test patch. Our removal page explains more.
Yes. We carry out repairs, cleaning and re-dashing for housing associations, landlords and other organisations as well as private homeowners. We can plan work across several properties, coordinate with tenants and provide clear written scopes of work. See our commercial page for more.
Most of the work is outside, so you can carry on as normal indoors. There is some noise when we cut out old render, and a scaffold may be up for a while on larger jobs. We keep paths clear, protect your garden and tidy up every day.
From the blog
Preparing for a Pebble Dash Job: Scaffolding, Neighbours and TimingA little planning makes any pebble dash job run more smoothly. Here is what to expect with scaffolding, neighbours, permissions and the weather.Read more 
Why Pebble Dash Cracks in Welsh WeatherRain blown in off the Atlantic, frost on the hills and salt on the coast all test pebble dash. Here is how weather causes cracking, and how to slow it down.Read more 
Can You Paint Pebble Dash? What to Know Before You StartPainting can transform tired pebble dash, but it is a long-term commitment. Here is what to consider, how to prepare and which coatings suit Welsh walls.Read more 
Repair, Re-Dash or Render? Choosing the Right Option for Your WallPatching, re-dashing and re-rendering all have their place. This guide explains when each makes sense, what they involve and the questions to ask before deciding.Read more 
Cleaning Pebble Dash Safely: Why Soft-Washing Beats the Jet WasherAlgae and moss love damp Welsh walls. Here is how to clean pebble dash without blasting the stones off, and how to slow down the green coming back.Read more 
How to Tell If Your Pebble Dash Needs RepairingA walk round the outside of your house can tell you a lot. Here are the simple checks that show whether pebble dash is sound or starting to fail.Read more Free survey and a clear written quote anywhere in South & West Wales.