Damp Proofing and Property and Preservation in Cambridge UK Anglia

DRYING OUT FOLLOWING DAMP-PROOFING/REPLASTERING

It must be remembered that, even after the insertion of a damp-proofing course, the moisture already present in the wall can only escape by evaporation. As a general guide, the drying rate is given as 1 month for every 25mm of wall thickness (BRE Digest 163, 'Drying out buildings'). Therefore a 225mm (9") solid wall will take approximately 9 - 12 to months to dry. NB Thicker walls will take correspondingly longer.

The drying out of the wall and the new plaster will depend on conditions in individual buildings/rooms and will be affected by ventilation and the type and thickness of masonry, how wet it was to start with, salt contamination levels, the seasons of the year, and current weather; so drying may take considerably longer.

Damp Proofing and Property and Preservation in Cambridge UK Anglia

External finishes, e.g. plastic coatings/paint/render, will considerably extend this time period.

After replastering the walls must be allowed to dry completely before applying a water-based trade matt emulsion paint, and at least six months must elapse before using wallpaper, gloss paint or ceramic tiles.

  • Delay any decoration for at least 4-6 weeks following replastering and allow for good natural ventilation to enhance drying. After this time period only use a non vinyl based emulsion.* Do not apply direct heat or accelerated drying methods, but gentle back ground heat and natural ventilation should be used.
  • Do not use wallpaper, textured wall coatings, oil-based paints or vinyl emulsions for at least 6 months on a standard 225mm wall. (Longer on thicker walls and ideally at least 12 months before papering)
  • Maintain good ventilation around walls and do not cover the walls with stored items or large pieces of furniture until the surface has fully dried out.

NB Redecoration carried out within the 9 - 12 month drying period using impervious wall coverings or paint will cause decorative finishes to bubble when residual moisture is prevented from dispersing, and may also cause the new plaster to lose key.

* Examples of suitable paint

Albany Supercover, Dulux Super Matt, Crown Cover Matt, Permoglaze High-opacity Emulsion or Leyland Super Matt.

These paints can be supplied by Brewers decorating suppliers at

4 Clifton Road Industrial Estate
Cambridge
Cambridgeshire
CB1 7EA

Tel: 01223 411420

Damp Proofing and Property and Preservation in Cambridge UK Anglia