Penetrating Damp Treatmentin Harrow & Surrounding Areas

Mortar joints are the sacrificial part of a wall, and on exposed London elevations they erode until rain sits in open joints and tracks inwards. Repointing puts that right, but only with a mix appropriate to the brick: a hard cement-rich mortar on soft Victorian stock brick forces moisture to escape through the brick face instead of the joint, and the faces then spall.

We cut out defective joints to a proper depth rather than skimming over them, match the mix and joint profile to the existing wall, and deal with the whole affected area so water is not simply diverted a metre sideways.

Cracked, hollow or blown render is worse than no render, because it collects water behind the face and holds it against the masonry. Tapping the elevation finds the debonded areas. Depending on extent, the repair is a cut-out-and-patch, a full re-render, or a change of system where the original mix was unsuitable for the substrate.

Where a solid wall is simply saturating through under driven rain, a breathable water-repellent façade cream can be specified. It reduces absorption while still letting the wall release vapour, which is the opposite of a sealing paint.

Windows and doors concentrate water. Perished mastic, a missing or reversed drip on a sill, a cracked cill, failed lead trays and open joints under copings and parapets all put water directly into the reveal, which is why staining so often frames an opening.

Repairs here are small in scale and disproportionately effective: renewing seals, reinstating throating or drip details, bedding loose copings and repairing defective sills.

A split downpipe, blocked gutter, failed gutter joint or overflowing hopper will soak a wall faster than any amount of driven rain, and will do it in a narrow vertical band that is easy to identify. Chimney flashings, abutments, valleys and flat-roof upstands cause the same pattern at high level and on ceilings.

We inspect and address these as part of the diagnosis, because there is no sense in repointing a wall that is being hosed by a broken pipe.

In cavity-walled properties, water crossing the cavity is usually mechanical: mortar droppings on ties, debris at the base, insulation slumped or badly fitted, or a tie sloping the wrong way. The pattern is often a discrete damp spot rather than a spread.

Where masonry has cracked because ties or embedded steel are corroding, the brickwork repair and any helical stitching are carried out alongside the damp work so the wall is sound as well as dry.

In houses and flats the priority is normally minimum disruption and a clean decoration-ready finish. In commercial premises: shops, offices, workshops; the same technical repairs are staged around trading hours, stock and access equipment, and high-level work on parapets and flat-roof details features more often.

Either way the quotation is a fixed price for a defined scope, paid 50% deposit and 50% on completion by bank transfer.