Deep detail
Types of damp, methods we use, and what's right for your property.
Damp isn't one problem - it's three or four very different problems that look similar on the wall. Treatment that works brilliantly for one type does nothing for the others.
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Rising damp and chemical DPC injection
True rising damp is moisture wicking up from the ground through capillary action in mortar, usually because the original damp-proof course has failed or was never installed. It stops at around 1.0–1.2 metres above floor level, leaves a salt 'tide mark', and reads high on a calibrated meter at low level only.
The correct fix is a chemical DPC: silane/siloxane cream is injected into the mortar bed at low level, where it cures into a water-repellent barrier. Contaminated plaster (which holds hygroscopic salts) is hacked off to 1m, replaced with a salt-resistant render and skim, and re-decorated. We guarantee this work for 10 years in writing.
Penetrating damp from outside
Penetrating damp comes through the building envelope - failed pointing, cracked render, blocked or overflowing gutters, slipped tiles, cracked lead flashings, defective window cills, or bridged cavities full of mortar snots. It typically shows as wet patches at any height, often worse after rain and driven by wind direction.
We trace the source, fix the external defect (repointing, render patch, gutter clearance and realignment, flashings, cill repair), allow the wall to dry, then reinstate the inside. Treating the inside without fixing the outside is a waste of money - the damp just comes back the next storm.
Condensation and mould (the most common cause)
More than half of the 'damp' we're called to in Teesside is actually condensation: warm, moist indoor air (cooking, showering, drying clothes, breathing) hitting cold wall surfaces and depositing as water. The classic sign is black spotted mould in corners, behind wardrobes, on window reveals and in north-facing bedrooms.
The fix is rarely chemical. It's a combination of ventilation (extractor fans correctly sized for the room, trickle vents, a Positive Input Ventilation unit for the whole house if needed), insulation (cold spots and lintels), and behaviour change. We treat the mould safely with fungicidal wash, repaint with anti-mould paint, and explain how to keep it gone.
Cellar and basement tanking
Cellars and basements in older Middlesbrough and Stockton properties were never built to be habitable. To use them as storage, utility or living space, they need to be tanked. We use either a cementitious slurry system (bonded direct to sound masonry) or a cavity drain membrane system with a sump and pump - chosen based on water table, structure and how the room will be used.
Timber treatment - wet rot, dry rot, woodworm
Damp ruins timber. Wet rot is common in window cills, door frames and joist ends. True dry rot (Serpula lacrymans) is rarer but far more destructive, spreading hyphae through masonry to find new timber. Active woodworm (Common Furniture Beetle) shows as fresh, sharp-edged exit holes with bore dust. We identify which is which, treat with the right product, replace structurally lost timber with seasoned new section, and guarantee the treatment.
