Rain stopped at the outside face, before it reaches your inside wall.
Exterior walls treated so wind-driven rain stops at the outside face: cracks cut open and filled, junctions sealed, then a flexible coating built over the whole elevation, not just patched where the damp shows inside.
- Free site inspection
- Written, itemised quote
- 1-year workmanship warranty
- Same-day callback
At a glance
Will exterior wall waterproofing stop the damp patch on my inside wall?
Only if the water is coming through that wall. Wind-driven rain gets into exterior plaster through hairline cracks, open mortar joints and unsealed window junctions, then shows up on the inside face. We trace where it's getting in, repair those routes, and coat the whole elevation with a flexible system that bridges hairline movement instead of splitting with it. Damp coming from a terrace, a leaking pipe or the plinth needs a different fix.
When this is the answer, and when it is not.
Sending you to the wrong service wastes your money and our time. This is how to tell.
This is likely right if
- A damp patch appears on the inside of an external wall during the monsoon and fades once the rain stops
- The south-west elevation takes the driven rain and its plaster is crazed with hairline cracks
- Exterior paint is blistering, chalking or lifting in sheets on one elevation but not the others
- The building is due for exterior repainting anyway and you want the water routes closed while access is up
Something else comes first if
- The damp sits at the bottom of the wall and stops about a metre up, that's rising damp through the plinth, and it needs plinth-level treatment, not a facade coating
- Water is tracking down from the terrace, parapet or a chajja above, that has to be waterproofed first, or the coating seals a wall that's still being fed from the top
- A concealed plumbing or drain line in the chase is leaking, the chase has to be opened and the line repaired before anything is coated over it
What the service includes.
Ingress survey
We walk the elevation and match the damp inside to what's happening outside, crack pattern, open mortar joints, window and sill junctions, the chajja underside, conduit and AC pipe penetrations, and where the old coating has lost its grip.
Moisture check and drying
Readings taken on the affected wall before we agree a start date. A wall still holding water can't be coated, the coating traps that water and blows off, so drying time is planned into the programme rather than skipped.
Crack cutting and joint sealing
Hairline crazing bridged, wider and live cracks cut back to a V-groove and filled with polymer-modified mortar, and window frames, sills and pipe penetrations sealed with a flexible sealant that can take movement.
Access and protection
Scaffolding or rope access as the elevation demands, with glass, grilles, sunshades, compound paving and anything below sheeted before the first tool comes out.
Primer and coating build
A primer chosen for the substrate and for what's already on the wall, then the waterproof coats applied to the stated film build across the full elevation, not only over the patch where the damp showed.
Wetting test and handover
The treated elevation wetted down and the inside face rechecked before we hand back, with the repairs, materials, coat count and the conditions of your written warranty recorded on paper.
Not included, or quoted separately
- Terrace, parapet-top, chajja-top and sunken-floor waterproofing, different systems on different substrates, quoted separately
- Plumbing, drainage and rainwater downpipe repair, including opening a chase to reach a leaking line
- Structural crack stitching, or any repair needing a structural engineer's design
- Re-plastering elevations where the existing plaster is hollow or debonded over large areas
- Making good and repainting the damaged inside face once the wall has dried out
The sequence.
Trace where the water gets in
Inside and outside inspected together, with the rain direction and the position of the damp both taken into account. If the source turns out to be the terrace, a chajja or a pipe, we tell you that instead of quoting a wall coating.
Survey, measurement and quotation
The elevation measured, the access method decided, and the repair scope written down crack by crack. The quotation names the system, the number of coats and the film build.
Set up access and protect
Scaffolding erected or rope access rigged, glass, grilles and paving sheeted, and a working sequence agreed so your windows aren't left open to the weather overnight.
Strip, repair and dry
Loose and chalking coating scraped and washed off, cracks cut and filled, junctions sealed, then the wall left to dry back to an acceptable moisture reading before anything is coated.
Prime and build the coats
Primer first, then the waterproof coats to the agreed thickness, with extra attention at cracks, junctions, copings and sill undersides, which is where water actually gets in.
Test, inspect and hand back
The elevation wetted, the inside face rechecked, snags closed, access dismantled and the site cleared, with your written record issued at handover.
What moves the price on this job.
We do not publish a rate, because it would change once someone measured your property. These are the variables that decide it.
- Measured elevation area, and how much of it sits at height rather than within reach from the ground
- The access method, ladder, scaffolding or rope access, and whether there's a setback wide enough to stand scaffolding in
- How much repair the plaster needs: crazing, live cracks, hollow patches and open junctions are the largest variable
- Whether the existing coating has to be stripped back to plaster or can be washed down and overcoated
- The waterproofing system specified and the film build it has to be applied to
- Whether the wall needs drying time before coating, which stretches the programme
Exterior Wall Waterproofing — your questions.
Can you do this work during the monsoon?
Not properly. The wall has to be dry when the coating goes on, and each coat needs dry weather to cure before the next one. Working in a wet spell traps moisture behind the film, which then blisters and peels once the sun is back on it. We can survey, quote and plan during the rains, and start once there's a settled dry spell.
The damp is inside. Why treat the outside wall?
Because that's where the water enters. On a driven-rain elevation, water passes through hairline cracks in the plaster and open mortar joints, moves through the wall and appears on the inner face, sometimes a metre away from the entry point. Sealing the inside face only traps that water in the wall and pushes the problem sideways. The inner face is repainted afterwards, once the wall has dried out.
Do you've to coat the whole elevation?
Yes, if the elevation takes driven rain. Coating only the wet patch leaves every other crack on that face open, and water simply enters through the next one. Treating the full elevation up to a natural break, a corner, a coping or a string course, also avoids a visible patch sitting in a different sheen and colour from the rest of the wall.
What about the wall shared with the building next door?
Where the setback is too narrow to work in, or the wall is shared with the building next door, there may be no way to reach the outside face at all. We'll say so at the survey rather than quote around it. What remains is treatment from your side, which manages the damp rather than stopping it at source, and we explain that difference before you decide.
Will waterproofing change how the wall looks?
Yes. These coatings are thicker and more flexible than exterior emulsion, so they sit slightly heavier over textured plaster and hold their own sheen. The colour choice is narrower than a standard exterior paint range, and a coating built to a stated film thickness reads as a more solid, uniform surface. We put a sample on your own wall and look at it wet and dry before you commit.
Let us look at your walls first.
Tell us about the property and we will set up a free colour and wall inspection. You get a written, itemised quotation afterwards, with no obligation to go ahead.
- We call you back the same day to get a picture of the property and the surfaces.
- We agree a time and come out for the free inspection.
- You get the written scope and itemised quotation.
- Nothing starts until you approve it.