Rising damp treatment in Boston

Rising damp is ground moisture climbing a wall through fine pores in brick and mortar. In most of England it is over-diagnosed. In Boston it deserves to be taken seriously. The town centre's Georgian and Victorian streets, the terraces off High Street, the older houses around Wide Bargate and down through Skirbeck, were built directly onto marine silt with either no damp proof course or a slate one that has long since cracked or been bridged. The ground they stand on was marsh before it was drained, and pumped drainage keeps the surface dry without doing much for the moisture held in the silt below.

That is why a tide mark on a hall wall in Boston is worth investigating rather than painting over. Left alone, rising damp ruins plaster, rots skirtings and floor joists, and carries ground salts into the wall that keep it damp permanently.

Signs it is actually rising damp

• A horizontal tide mark, usually stopping within a metre or so of the floor
• White fluffy salt deposits on the wall surface as it dries
• Peeling paint or paper at low level, with sound decoration above
• Damp, musty skirting boards and rotting floor timbers near external walls
• Plaster that feels cold and clammy at the base of the wall in dry weather

Condensation and penetrating damp mimic some of these signs, and each has a different fix. The specialist confirms the diagnosis with moisture profiling before recommending treatment, which protects you from paying for a chemical damp proof course you never needed.

How treatment usually works

1. Inspection and diagnosis. Moisture readings taken at intervals up the wall, a check for bridging, raised ground levels, leaking gutters and plumbing, and a look at the existing damp proof course if one exists.
2. Deal with the causes first. Raised flower beds, render bridging the damp course, and blocked air bricks are common in Boston's older streets and sometimes solve the problem on their own.
3. Remedial damp proof course. Where genuine rising damp is confirmed, a new chemical damp proof course is injected into the mortar bed and left to cure.
4. Salt-contaminated replastering. Affected plaster is removed to the specified height and replaced with a salt-resistant system, because contaminated plaster stays damp even after the wall dries.

Older and listed buildings

Parts of central Boston fall within the conservation area, and buildings near the Market Place, South Square and the riverside often need a gentler approach: lime-based plasters that let the wall breathe, and drainage or ventilation improvements before any injection is considered. If your property is listed, mention it when you enquire so the right method is proposed from the start.

What it costs

Cost depends on the length of wall affected, access, and how much replastering follows. A single wall in a terrace is a different job from the full perimeter of a detached house. The specialist quotes after inspecting, so the figure reflects your walls rather than a national average.

Related pages: damp surveys, condensation and mould, timber and woodworm.