Damp proofing in Gravesend? Get an independent survey first

Why the survey comes before damp proofing in Gravesend

Damp proofing is the answer to one specific fault, a missing or failed damp proof course, and that fault is far rarer in Gravesend than the quotes suggest. Before anyone drills a wall, somebody with nothing to sell should establish why it is wet. That is the whole of what we do. We carry out no treatment, so the survey is not a route to a sale.

In the Victorian streets the familiar quote is injection along the party and rear walls with full replastering in a sand and cement mix. Injecting a party wall is almost never justified, because it is sheltered and often shares its moisture with the house next door. Along the rear, the yard and the downpipes are usually the cause. In the riverside conversions the quote is often tanking an above ground wall that is wet from failed stucco or a parapet.

Injection, tanking, membranes: what they are for

Injection is for rising damp: groundwater drawn up a wall that has no working course. Tanking and cavity drain membranes are for walls below ground that hold back soil and water, such as cellars and basements. Salt resistant replastering is for walls where years of damp have left salts in the old plaster. Ventilation is for condensation. A quote that applies one of them to the wrong problem will fail however well it is installed.

In Gravesend the commonest mismatch we see is injection and a cement based replaster on a wall whose real trouble is outside: open joints, raised ground or a leaking downpipe. Fix those and the wall often dries without anything being injected at all.

Gravesend walls, and what they actually need

Gravesend's older walls are soft stock brick in lime mortar, sometimes behind stucco, and they need to breathe. A gypsum or cement plaster sealing the inside face pushes moisture higher and leaves salts behind. Lime or a breathable lightweight plaster suits them, and so does keeping the ground clear of the course outside.

The town sits on chalk, which was quarried heavily around Northfleet and Swanscombe, and the riverside flats are low and alluvial. On the chalk, water drains quickly and damp tends to follow the weather. Near the river the water table is high and responds to tides and rainfall, which affects cellars and basement flats. The Thames itself is the source of the exposure: easterly and westerly winds funnel along it and drive rain into the north facing elevations of the riverside streets.

• Lowering rear yards or adding a drained channel along the wall where the ground has risen
• Repairing and repainting stucco in a breathable finish instead of sealing it
• Fixing parapet gutters, hoppers and soil stacks on converted buildings, usually through the freeholder
• Improving extract ventilation and heating in post war houses with mould

What proper damp proofing should look like

• A written diagnosis first, with readings and photographs, saying why the wall is wet
• External causes fixed before or alongside any internal work: ground levels, gutters, pointing, render
• A damp proof course only where one is missing or has genuinely failed, at the right height for the Gravesend house in question
• Salt contaminated plaster removed and replaced with a suitable breathable or salt resistant finish, not sealed over
• Drying time allowed before decoration, because a wall that has been wet for years does not dry in a week
• A guarantee that names the walls treated and the cause addressed, from a firm that will still be there

Questions to put to anyone quoting

• Why is this wall wet, and what is the evidence?
• Have you checked the ground level, gutters and pointing outside, and what did you find?
• Would the damp stop if those were fixed, and how do you know it would not?
• Why this height of replastering, and why this material?
• What exactly does the guarantee cover if the damp comes back in this Gravesend house?
• Can I have the survey in writing before I decide?

When a damp proof course is the right answer

There are walls in Gravesend that do need a damp proof course. A solid wall built without one, or with a slate or bitumen course that has cracked or been cut through, that is wet at low level with nothing outside to explain it and with the readings falling off with height, is a reasonable candidate. When we find that, the report says so and specifies where and how high, so you can get comparable quotes.

Our survey fees are published on the prices page and fixed before we visit. Set against a damp proofing job on a Gravesend house, which typically runs to several times that once plaster removal and making good are included, the survey is small. When it shows that a wall needs a gutter repair rather than an injected course, it pays for itself several times over.

If you are buying an older Gravesend house and the homebuyer report mentions damp, the wall in question is probably solid brick and the reading may be salts, a raised yard or a gutter. For a flat in a converted riverside building, the cause may belong to the freeholder. An independent survey before exchange says which, and gives you a basis to negotiate or to ask the seller or freeholder to act.

What you do with the report is up to you. Most people fix the outside faults first, which are usually the cheapest, and give the wall a season to dry. Some take the specification to two or three Gravesend contractors. Some send it back to the firm that quoted, which often changes the quote.

For the full picture of what a survey here involves, see damp surveys in Gravesend.

Around Gravesend

The riverside and old town

Older buildings with basements, shops with flats above, and conversions. Defective parapet gutters and stucco are the recurring causes, and responsibility often sits with a freeholder rather than a flat owner.

Milton and Windmill Hill

Long runs of Victorian terraces on rising ground. Rear yards, lean to roofs and suspended timber floors with airbricks that have disappeared under paving are where most of the trouble starts.

Riverview Park, Singlewell and Istead Rise

Mid and late twentieth century housing. Mould in bedrooms and bathrooms, failed extract fans and cavity insulation problems make up most of the surveys here.

Damp proofing questions in Gravesend

Nearby

• Damp proofing in Dartford
• Damp proofing in Rochester
• Damp proofing in Snodland

Book a survey before you pay for damp proofing

An independent survey before you pay for damp proofing in Gravesend. Fixed fee, same day reply, written report within 24 hours.

Book a Survey or call 07386 225526