Damp proofing in Dartford? Get an independent survey first

Why the survey comes before damp proofing in Dartford

A free damp survey in Dartford is usually a sales visit with a meter. The meter reads high on a wall that is wet for any reason, and on salts in old plaster even when the wall is dry, so a high reading proves very little. An independent survey finds the cause, and only the cause tells you whether damp proofing is the remedy at all.

The quote we are most often asked to check in Dartford is chemical injection along the front and rear walls of a Victorian or interwar house, with a metre of hacking off and replastering. In a large share of those houses the existing course is intact and has been bridged by a raised yard or driveway, or the damp follows the rain and comes from a gutter or a gully. Injection leaves the bridge in place, and the new plaster simply hides the problem for a winter or two.

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 Dartford 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.

Dartford walls, and what they actually need

Most older Dartford houses are yellow stock brick in lime mortar, with a slate or bitumen course a couple of courses above the original ground. They cope well with damp so long as the ground stays below the course and the brick can dry out. The newer homes by the river are cavity built with modern membranes, where damp is almost always about ventilation, construction moisture or a detail such as a door threshold or balcony outlet.

The Darent runs north through the town to the Thames, and the land falls from the chalk of the downs to the river flats and the Dartford and Stone marshes. Chalk quarrying shaped the riverside for a century, which is why so much of the newer housing sits on reworked ground and why some gardens end at a cliff of white rock. Uphill, the chalk is overlain in places by clays and gravels that hold water for longer, so two streets a few hundred metres apart can behave quite differently after a wet week.

• Lowering yards, drives and patios so the existing damp proof course is clear again, or adding a gravel drain alongside
• Clearing and repairing gullies and downpipes, which on chalk shows up quickly as drier walls
• Removing salt contaminated plaster only where it is, and replacing it with a breathable finish
• Fixing extract ventilation in flats rather than applying anything to the walls

The signs of a damp proofing job worth paying for

• The contractor can tell you the cause in a sentence and show you the evidence
• The quote mentions what is happening outside the Dartford house, not only inside
• Plaster removal is limited to where salts actually are, with a height that matches the readings
• Materials are named and suit the wall, rather than a standard system applied to every house
• The guarantee is insurance backed or otherwise protected, and states exactly what it covers
• Nobody pressed you to sign on the day

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 Dartford house?
• Can I have the survey in writing before I decide?

When a damp proof course is the right answer

There are walls in Dartford 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 Dartford 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.

Buying in Dartford often means choosing between an older terrace near the station and a newer home by the river. They fail differently. On the terrace, a homebuyer report flagging damp usually means ground level or rainwater, and the fix is modest if it is diagnosed properly. On the new build, damp in the first year or two is often construction moisture or ventilation, and some of it may still be the developer's responsibility under warranty. Either way, an independent survey before exchange tells you which.

After the survey you have the cause in writing, a list of what needs doing in order, and what does not. If damp proofing is part of it, the report specifies the walls, the height and the finish, so the quotes you collect in Dartford are for the same job. If it is not, you have the evidence to say no to the quote you were given.

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

Around Dartford

Town centre and West Hill

Victorian and Edwardian terraces, many now flats or let, with rear yards that have been concreted and re concreted. Rear wall damp in a kitchen extension is usually a yard level or a leaking waste, not rising damp.

Wilmington and Joydens Wood

Interwar and post war semis and bungalows on larger plots. Driveways and patios laid across the front and side are the classic bridging fault, along with airbricks buried behind them.

Greenhithe, Stone and Swanscombe

Older terraces near the river alongside large recent developments on former industrial land. New build questions here are about ventilation, construction moisture and drainage settling in made ground.

Damp proofing questions in Dartford

Nearby

• Damp proofing in Swanley
• Damp proofing in Gravesend

Book a survey before you pay for damp proofing

Holding a damp proofing quote? Book a survey and we will tell you whether it matches what is actually wrong with your Dartford home.

Book a Survey or call 07386 225526