Structural timber — joists, rafters, floorboards, and roof timbers — forms the skeleton of your property. When it is affected by rot or woodworm, the integrity of the entire building is compromised. Timber decay is progressive, hidden, and far more serious than most homeowners realise until significant damage has already occurred.
Timber decay thrives in damp, poorly ventilated conditions — which is why it so often accompanies damp problems in Irish properties. By the time decay becomes visible, it has usually been progressing for months or years within the structure.
Despite its name, dry rot requires moisture to begin — but once established it can spread rapidly through masonry as well as timber, even crossing gaps. It presents as cracked, cube-like timber with a distinctive musty smell and often a grey, cotton-wool-like mycelium. It is the most serious form of timber decay and requires urgent treatment.
Wet rot requires a continuously damp environment to survive. It causes timber to become soft, spongy, and discoloured — darkening significantly compared to surrounding sound wood. It is more localised than dry rot but still causes serious structural weakening if left untreated.
Woodworm is the larval stage of wood-boring beetles. The larvae tunnel through timber for years before emerging as adult beetles, leaving the characteristic small round exit holes. Heavy infestation severely weakens structural timbers. Fresh flight holes (clean edges, pale interior) indicate active infestation requiring treatment.
Affected floor joists, rafters, and roof timbers can fail structurally. In severe cases, floors become unsafe and roofs require significant repair. Insurance claims for undisclosed timber decay are frequently disputed. Early treatment is always a fraction of the cost of structural repair.
Timber decay does not pause. Every month without treatment means more of your structural timber is being compromised — and the repair cost grows accordingly. If you've spotted any of the warning signs, act now before it becomes a structural issue.