Damp proofing and timber treatment in Barnsley

Most damp in a house comes from one of a few places: the ground, the rain, the air inside, or a leak. A damp proofer worth calling works out which before recommending anything, because each needs a different fix.

In a Barnsley terrace that means checking the ground levels and air bricks outside, the pointing, gutters and downpipes, how the house is heated and aired, and the floor timbers underneath.

You should get a clear explanation in plain words, a quote that says what it covers, and honest advice on anything you can put right yourself. See how we approach damp proofing.

If moisture is rising from the ground past a failed damp proof course, the treatment is a new damp course and fresh plaster: see rising damp treatment.

If rain is getting in through worn pointing, cracked render or a leaking gutter, the treatment is outside, and then the wall is left to dry. The solid brick walls of Barnsley's terraces are especially open to it. See penetrating damp.

If the damp is condensation, the treatment is ventilation and steady heat, not damp proofing at all.

A typical Barnsley terrace has solid brick walls and, if it has a damp proof course at all, one that is more than a hundred years old. Where moisture from the ground is rising past it, a water-repellent cream injected along a mortar course near the bottom of the wall forms a new one.

Before injecting, anything bridging the old damp course has to go: a raised yard, a path, or render that runs down over it. Sometimes that alone solves the problem.

Afterwards the salt-damaged plaster is replaced, as salts left in the wall keep drawing in moisture. More on rising damp treatment.

The suspended timber floors in Barnsley's older terraces rest on joists a short way above the ground, kept dry by air flowing in through air bricks. When those air bricks are blocked, or the walls are damp, the joists and boards stay wet.

Wet timber is where rot starts, and woodworm does best in it too. Roof timbers suffer the same way under a leaking roof or a blocked gutter.

Treatment means fixing the damp, treating the sound timber with a preservative and replacing what has lost its strength with treated timber. See how timber is treated.

In a solid-walled terrace, timber touches the walls everywhere: skirting boards, the ends of floor joists, door frames and window boards. If the wall is damp, from rising damp, rain getting in or a leaking gutter, that timber stays wet and rots.

Often the first sign is a skirting board that has gone soft, or plaster above it that crumbles. Behind it, the joist ends may have rotted too.

The damp is fixed first. Then rotten timber is cut out and replaced with treated timber, and the timber around it is treated. Dry rot, which can spread across brickwork, is treated over a wider area. See wet and dry rot.

The common furniture beetle attacks softwood: floorboards, joists, stairs and roof timbers, all of which Barnsley's older houses are full of. It does best where the timber is damp, such as a floor that stays damp underneath (see timber treatment) or a roof that has leaked.

Fresh, pale dust below the holes and clean-edged holes mean it may still be active. Dark holes with no new dust usually mean it died out long ago.

Where it is active, the affected timber and the timber around it are treated so beetles die as they come out and new larvae cannot get in. See how woodworm is treated.