Caernarfon, Gwynedd
Stone that was built
to breathe, and then sealed.
Caernarfon's older stock is stone and slate, put up long before anyone thought about impermeable barriers. Almost all of it has since been rendered, painted or floored in something that stops it drying — and that single decision causes more damp here than the weather does.
The local stock
What Caernarfon is built from.
Historic stone, tight streets
Solid stone with lime mortar, shared party walls and very little space between buildings. Rain reaches the wall but sun and wind often do not, so drying is slow and any impermeable coating turns a damp wall into a permanently wet one.
Slate-hung and rendered stone
Slate-hung weather elevations over stone, frequently over-rendered in cement. The slate is doing its job; the render behind it traps what gets past. Failures show at the junctions rather than in the middle of a wall.
Empty, unheated, unventilated
A property closed up from October to March with the heating off grows mould whether or not it has a water problem. It is the most common call we get in Caernarfon in spring, and the fix is management rather than treatment.
Concrete over an earth solum
A concrete slab laid over what used to be an earth or slab floor pushes moisture sideways into the base of the walls. The tide mark that follows gets diagnosed as rising damp and injected, and it comes straight back.
Worth knowing
Yn Gymraeg, os yw'n well gennych.
Caernarfon has among the highest proportions of Welsh speakers anywhere in Wales, and a survey is easier to follow in the language you think in. We are happy to carry out the visit and talk it through in Welsh.
The written report is produced in English as standard — say the word if you would prefer it the other way round and we will sort it.
What you get
The survey itself.
Internal moisture profile
Readings at height intervals across affected walls, so a pattern emerges rather than a single number.
Salt analysis
Hygroscopic salts separate genuine rising damp from a leak or from condensation. It is the test most treatment quotes skip.
External defect inspection
Render, pointing, downpipes, ground levels, slate. The cause is outside far more often than it is in the wall.
Air and surface conditions
Temperature, humidity and surface readings — the evidence that separates a ventilation problem from water ingress.
Independent and insured. We survey; we do not sell treatments, so there is no quote waiting at the end of the report.
Nearby
Also covered from Llangefni.
Caernarfon and the surrounding area
Find out what it actually is.
Tell us the postcode and what you are seeing.