It’s that time of year again when it’s no fun to be on a building site when temperatures have dropped significantly or the rain is driving horizontally. It’s not just you and the packed lunch that need to be protected. The Brick Development Association make a number of recommendations for protecting newly laid masonry in colder months.  

(Picture courtesty of Ockwells.com)

  • Brickwork should be kept clean and protected from rainfall, snow and contamination.
  • Avoid mortar smearing or splashing as the work proceeds.
  • Staining of brickwork often comes from excessive wetting or saturation of recently built brickwork.
  • During breaks in construction, take particular care to keep bricks and brickwork in progress covered with waterproof sheeting.
  • Bricklaying should normally stop when the temperature is 3° Celsius and falling and not begin again until the temperature reaches 3° Celsius and rising.
  • If overnight frost is likely before the mortar within newly constructed brickwork has fully set, it should be protected with an insulating layer of hessian underneath the polythene. This would normally give some protection to the mortar joints from overnight frost.

If frost attacks mortar it loses its key and the strength of the wall can be compromised. Rain penetration can also wash fines onto brickwork or into a cavity making the wall look unsightly. Both can also worsen sound insulation if mortar is forced into a cavity. Likewise timber frame sheathing can swell when wet and reduce the cavities' acoustic performance. 

So don’t forget your polythene membrane and hessian to keep your masonry looking good.

You can also keep it all year round as it can also be used in hot weather to protect the mortar from drying out too quickly. Don’t be tempted to wet it first though as this will likely just lead to staining of the brickwork.

Further information

To download the guidance or read up on their technical documents, visit:

http://www.brick.org.uk/2016/09/good-site-practice-workmanship/

http://www.brick.org.uk/category/publications/bda-guides/

 

By LABC