FAQs

Black staining on stone buildings is most commonly caused by atmospheric pollution, particularly carbon deposits from vehicle emissions and industrial activity. Over decades, these particles settle on the stone surface and bond with moisture and biological growth such as algae, lichens, and moss. In coastal and damp areas like Cardiff and Penarth, the combination of moisture and pollutants accelerates this staining. Professional stone cleaning can safely remove this buildup and restore the natural appearance of your stonework.

Generally, standard stone cleaning and restoration work does not require planning permission. However, if your property is a listed building, you will need Listed Building Consent from your local authority before carrying out any work that alters its character or appearance. If your property is in a conservation area, some external works may also require planning approval. We recommend checking with your local council or Cadw (the Welsh Government historic environment service) before starting work. We are happy to advise on this during our initial consultation.

For buildings constructed before approximately 1919, lime mortar should always be used instead of cement. Cement mortar is too hard and rigid for older stone and brick buildings, which need to flex and breathe. Using cement on old stone traps moisture inside the masonry, leading to damp problems, salt crystallisation, frost damage, and accelerated stone decay. Lime mortar is softer than the stone it surrounds, allowing moisture to escape naturally and protecting the building for generations to come.

In many cases, damaged Bath stone can be repaired rather than fully replaced. Techniques include stone indenting (cutting out the damaged section and inserting a new piece of matching Bath stone), lime mortar repairs for minor surface damage, and consolidation treatments for friable stone. However, if the stone is severely decayed or structurally compromised, replacement with new Bath stone may be necessary. We assess each case individually to recommend the most appropriate and cost-effective solution.

Stone cleaning removes surface dirt, biological growth, pollution staining, and discolouration from the existing stone without altering its structure. Stone restoration goes further and involves repairing or replacing damaged stone, repointing mortar joints, rebuilding deteriorated sections, and conserving the structural integrity of the stonework. Many projects require both cleaning and restoration to achieve the best results.

Vale Stone Masonry provides professional stone masonry services across Cardiff, Penarth, Barry, Cowbridge, Dinas Powys, Sully, Llandaff, and the wider Vale of Glamorgan and South Wales region. Whether you need stone restoration, Bath stone cleaning, stone carving, or repointing, we cover both residential and commercial properties throughout the area. Get in touch to discuss your project.

The duration of stone cleaning varies considerably depending on the size of the area being treated, the type of stone, the level of soiling or biological growth, and the cleaning method required. Every job is different and we always assess each project individually before giving any indication of timescales. For a realistic estimate specific to your property, contact us for a free assessment.

The cost of stone masonry restoration in Cardiff varies depending on the scope of work, the type of stone, and the condition of the existing stonework. As a guide, day rates for skilled stonemasons in the Cardiff area typically range from £250 to £350 per day. For a free, no-obligation quote tailored to your specific project, please contact Vale Stone Masonry on 01446 622122 or 07500 871 637.

Take a look at our testimonials page which is always updated with current jobs or pay a visit to one of our ongoing jobs to see the transformation, simply contact us today to arrange a visit.

Yes, we often do commercial and domestic work which is then settled by insurance. To request for more information simply contact us today.

No we always do our best to stay as traditional as possible & our rule of thumb is that no chemicals should be used on bath stone. To request for more information simply contact us today.