Pointing is the term given to the final process of finishing brick, block or stone perpends and bed joints to give a neat, weatherproof appearance. Original pointing is either applied as construction proceeds (jointing) or is applied after construction has been completed.
Buildings are sometimes repointed to deal with deteriorated joints due to time and sometimes to provide a more durable finish and prevent Penetrating Dampness. The latter can lead to severe problems in older buildings and structures, as mistakenly, a very strong composition is often selected in the belief that it will give better protection.
Older buildings and structures were often constructed of porous materials bedded in a soft Lime Mortar. The effect of applying a modern hard mortar mix when repointing can be the suffocation of the building or structure.
|Instead of penetrating moisture being allowed to follow a natural route of evaporation via the Lime Mortar, moisture becomes trapped in the structure.This can lead to the movement of moisture to the internal faces of the building, spoiling decorations and causing damp stains. It can also lead to frost damage and unsightly salting.
Damp walls where moisture is trapped lose some of their natural thermal properties and therefore can become more susceptible to condensation and also lead to rapid heat loss.
The selection of materials and composition for repointing is critical and should be left to the professional. The final mix must be carefully matched to the brick or stone work and the original mortar to ensure it is durable but no stronger than the substrate.
The use of good quality materials, batch mixed, can ensure that shrinkage is kept to a minimum.
Externally applied hard renders have a similar effect to suffocating a building and will often debond from the substrate in large sheets particularly as a result of frost damage. Again specialist advice should be sought prior to applying rendering or rerendering, particularly if problems are being experienced with Penetrating Damp.
Protectahome carry out repointing and rerendering works (including Lime Pointing and Rendering) in association with specialist Structural Repairs and general Building Repairs. Able to deploy capable experienced personnel, we can ensure that the right materials are specified and that they are applied with skill and care.