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Porthmadog, Gwynedd

Basement Tanking in Porthmadog

Cementitious tanking and cavity drain systems for basements, cellars and below-ground rooms.

If you are weighing up basement tanking in Porthmadog, the starting point is what your walls are actually built from.

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.

Local conditions bring among the highest rainfall in the UK with severe exposure, and that has a direct bearing on which systems are worth specifying. Snowdonia records some of the highest rainfall in britain, and any non-breathable render on stone here will trap water within a single winter.

When basement tanking is the right call. Choose tanking for cellar and basement conversions, persistently wet below-ground rooms, and any space you intend to make habitable.

Guide price in Porthmadog

Guide price£115–£195 per m²
Applied thicknessMulti-coat cementitious system
Guarantee20 years

Indicative only. The guide-price tool gives a range for your property; the survey gives the fixed price.

What the job includes

  • Cementitious tanking slurries
  • Cavity drain membrane systems
  • Sump and pump installation
  • Type A and Type C waterproofing
  • Fillets and junction detailing
  • Withstands hydrostatic pressure

We will survey the property, tell you what the walls actually need, and put it in writing with a fixed price.

Also covering near Porthmadog

Basement Tanking in Porthmadog

Tell us about the property and we will call you back to arrange a survey.

Free survey · no obligation · fixed written quote

Guaranteed workmanship
Free written survey
System-warranted builds
UK-wide coverage
Fixed price, no surprises

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 Porthmadog

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.

How long before I can paint new render?

Through-coloured systems need no painting at all. Sand and cement should cure for around 28 days before masonry paint goes anywhere near it.

Do you take a deposit?

For most domestic jobs we take a deposit to cover materials and scaffold, with the balance on completion. Terms are set out clearly in the written quote.

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.

Free survey in Porthmadog

We will confirm whether basement tanking suits your walls before quoting a price.

Call Get a quote