Wales
Basement Tanking in Gwynedd
Cementitious tanking and cavity drain systems for basements, cellars and below-ground rooms.
Basement Tanking in Gwynedd is work we take on regularly, and the Gwynedd housing stock is a big part of why.
Gwynedd is characterised by slate and stone cottages, quarry housing and exposed coastal properties, with extreme driving rain on slate and stone construction the recurring theme on the properties we survey. With among the highest rainfall in the UK with severe exposure, specification matters more in this part of the country than a national price list suggests.
Local factor. Snowdonia records some of the highest rainfall in britain, and any non-breathable render on stone here will trap water within a single winter.
Is basement tanking right for a Gwynedd property?
Choose tanking for cellar and basement conversions, persistently wet below-ground rooms, and any space you intend to make habitable.
That decision gets made at the survey, not on the phone. We will tell you plainly if a different system would serve the building better — including when a cheaper one would.
Guide price and specification
| Guide price | £115–£195 per m² |
|---|---|
| Applied thickness | Multi-coat cementitious system |
| Curing / drying | 7-14 days |
| Guarantee | 20 years |
| Coverage | All of Gwynedd — 10 towns and cities |
Indicative only, excluding scaffold, stripping and repairs. Try the guide-price tool for a range based on your property.
What is included
- Cementitious tanking slurries
- Cavity drain membrane systems
- Sump and pump installation
- Type A and Type C waterproofing
- Fillets and junction detailing
- Withstands hydrostatic pressure
- Suitable for habitable conversion
- Salt and negative pressure resistant
Basement Tanking across Gwynedd
Basement Tanking in Gwynedd
Tell us about the property and we will call you back to arrange a survey.
Other services in Gwynedd
What happens next
Four steps from enquiry to finished wall
Free survey
We visit, test the substrate, measure up and identify what caused any existing failure.
Written quote
An itemised fixed price with the system named, materials specified and scaffold included.
Booked in
An agreed start date, scaffold arranged, and a clear run of days set aside for your job.
Finished and guaranteed
Site cleared, scaffold struck, guarantee documents and system warranty issued.
FAQs
Basement Tanking in Gwynedd — questions
Can you match my existing render?
Usually, yes. We colour and texture match as closely as we can, though weathered render never matches a fresh batch exactly — we will be honest about how visible a patch will be.
Can any cellar be tanked?
Most can, but the right system depends on water pressure, structural condition and intended use. A survey establishes which approach is appropriate.
How long does basement tanking last?
A correctly designed and installed system carries a 20-year warranty. Type C systems need periodic pump servicing to maintain that.
How long does a rendering job take?
A typical three-bedroom semi is usually one to two weeks on site including scaffold, preparation, application and finishing. Weather, wall condition and the system chosen all move that.
Do I need planning permission to render my house?
Usually not on a standard house, but you will if the property is listed, in a conservation area, or if rendering would significantly change its appearance. We flag it at survey.
Will you need scaffolding?
For anything above single storey, yes — it is safer and produces a better finish than working off ladders or towers. Scaffold is included and itemised in the quote.
Basement Tanking quotes across Gwynedd
Free survey, honest advice on whether this is the right system, and a fixed written price.