Replastering Damp Walls

Damp and Mould Solutions’ replastering service is the perfect complement to our damp and mould remediation services. In most of our damp repairs, we remove damp and mould damaged plaster and apply fresh water-resistant render and plaster.

Replastering of Damp Walls is an important step of a full remediation service following the application of the Damp Proof Course. Our objective with all clients is to remove the source of the damp problems, and repair the visual appearance of the affected walls.

However, we also want our clients to be confident the problem will not return weeks or months after. When necessary the replastering is an essential step of the repair process.

Why Replastering Damp Walls Necessary

Our post-damp replastering service is important for multiple reasons. It is not only about repairing the visual damage caused by dampness. While repairing the appearance of damaged walls is important, ensuring that the underlying problems do not return causing further damage and cost is the primary concern.

Ensuring the root cause of the moisture damage is resolved is the only way to ensure a safe, healthy, and comfortable environment alongside the visual aesthetic restoration improvements.

Replacing Damp Wall Plaster

Damp and mould have a lasting effect on plaster once it has infiltrated the material. A range of common signs can identify the need for damp remediation, but further inspection is required to know the extent of damage. In many damp wall cases, the level of moisture contamination in damaged sections of the wall is beyond saving and needs to be replaced.

Cracks, Bubbling & Blistering: Structural damage to the plaster occurs where water and moisture have been contact with the wall and subsequently been absorbed.

Musty odor: Dampness often produces a musty or moldy smell. If you detect an unpleasant odor in the affected area, it may indicate dampness.

Dampness and Water Stains: Visible yellow stains on walls show exactly where the moisture has reached when moving through the plaster. Where the plaster is damp to the touch, mould will likely be already present due to the plaster’s inability to repel moisture.

Salt deposits: Dampness can dissolve salts in the wall material, and when the moisture evaporates, these salts may be left behind on the surface, appearing as white or efflorescent deposits.

The risk of not replacing wall plaster that has been affected by damp, is that salt deposits from the moisture will remain in the wall attracting damp problems after the work is completed.

Replastering and Salt Contamination 

Hygroscopic salts enter walls from damp environments. Typically from high humidity or water in the ground, but also from damage associated with plumbing issues and leaking pipes.

When the moisture penetrates the walls, the salts can find their way into brick and plaster through the tiny pores ultimately dissolving into the construction material. Once the moisture itself has evaporated or dried out, the salt itself can be left behind leaving a crystalized white residue.

Similar to ordinary table salt, hygroscopic salt absorbs and attracts water from its surroundings which can lead to a recurrence of damp wall problems if not treated and completely removed.

Replastering walls by repairing only the visible damage can miss the highly integral requirement of identifying and resolving any present and future moisture infiltration.

Wall Plaster Salt Contamination Treatment

The first step for replastering treatment is to ensure that the path of water is prevented from recurring. Identifying and eliminating the source of dampness such as leaks or damp proof course issues is crucial.

Once the area is ready to be worked on, the most effective way of dealing with salt contamination in wall plaster is to remove plaster that contains any hygroscopic salts. If the salts are not removed prior to replastering damp walls, they will attract water even after a damp course is applied.

This is an important step in the process before starting replastering repair work that ensures the problem is not just delayed instead of resolved.

Treat & Seal Wall: Following the removal of damaged plaster, the walls must be treated with a dampproofing solution. A damp proof membrane can add further moisture protection.

Delaying Replastering: Time is a factor when it comes to replastering damp walls. We advise that the replastering should be delayed for long enough so any salts are dispersed.

Salt Retardant Plaster: Instead of replastering walls with standard plaster, the best choice is to use salt retardant plaster which is designed to hold back any hydroscopic salts still present in the walls during the complete drying period and beyond.

Waterproofing Additives: Adding additives that contain waterproofing is important as an additional barrier for keeping salts away from the freshly replastered walls. Waterproofing additives allow the safe passage of water vapor.

Monitor and maintain: Regularly inspect the treated area for signs of recurring dampness, leaks, or mold. Address any issues promptly to prevent further damage.