Masonry work with frost

What to do during cold weather

In case of frost it should be checked in individual cases whether masonry can even be built, and if so, this may only take place under special protective measures (winter construction site, heated full weather protection). If no special measures were taken, masonry work should be stopped in case of expected frost and for temperatures ≤ +5 °C. The same applies to normal, light-weight and thin-bed mortar.

The strength formation of the mortar slows down with decreasing temperatures and practically stops at - 10 °C. Due to the volume increase when water changes into ice, fresh or still hardly firm mortar is disrupted in its structure. Frost effects early on impacts the required mortar strength permanently. Later frost effects, e.g. 14 days later no longer impact the tensile strength.

As a rule frost protection agents are not allowed and no frozen building materials may be used. Fresh masonry must be covered in time before frost occurs. Continuing to brick up on frozen masonry is not allowed. The use of thawing salts is not permitted. If parts of the masonry are nevertheless damaged by frost, these parts must be removed prior to continuing construction.