Rising Damp vs Lateral Damp vs Penetrating Damp: What's Actually Wrong With Your Wall

"Damp" gets used as one word for a handful of different problems, and that's exactly why so many damp treatments fail, the wrong product gets applied to the wrong kind of moisture, the wall looks fine for a few months, and then the same patch comes back. Before you buy anything, it's worth knowing which of the three you're actually dealing with.

This is moisture traveling up through a wall from the ground, usually because the original damp-proof course has failed or was never installed properly. It tends to show up low on a wall, think the bottom third or so, often with a tide-mark line, flaking paint, or that crumbling, powdery efflorescence look.

What treats it: DampChem is an injection fluid — a blended silica/silicone solution designed specifically for rising damp, applied at a rate of roughly 2–3 linear metres per litre to create a new chemical damp-proof course where the original one has failed.

This is moisture moving sideways through a wall, rather than rising from below — common in retaining walls, below-ground structures, or walls backing onto raised garden beds where soil sits against the structure. It doesn't always leave an obvious stain. Sometimes it's just a wall that never quite feels dry, or paint that keeps failing in the same spot no matter how many times it's redone.

What treats it: RefurbiSol is a pre-mixed liquid plaster additive formulated specifically for treating lateral damp and plaster tanking in below-ground applications.

This is water getting in from a specific point , a crack, a failed seal, a gap somewhere in the structure, rather than rising or moving laterally through the material itself. It can look similar to rising damp but usually has a clearer point of entry once you go looking for it.

What treats it: RefurbiCrete is a plaster additive designed to assist in plastering damp walls affected by rising or penetrating damp, formulated for ease of use.

Not everyone wants to commit to a 20l drum of material and that's a fair place to be. The Damp-DIY Kit is a collection of products designed to treat small areas of rising, lateral penetrating damp. Simply add cement, sand, some equipment and know-how.

Treating lateral damp with a rising-damp injection fluid — or the other way around — doesn't just waste money. It can mean the wall looks treated for a while, then fails again in exactly the same spot, and now there's paint or plaster over the top making the next diagnosis harder.

Figuring out which type of damp you're actually dealing with before you buy anything is the step that makes the rest of the job worth doing.

If you're genuinely unsure, send us a photo of the affected wall — where it is on the wall, how it looks, whether it's near ground level or below-grade — and we can help point you toward the right product before you commit to one.