All clay bricks have a durability designation rating and it is important to know which bricks to use and where. Generally external works such as retaining walls, garden walls and copings, and building features such as sloping areas, parapets, sills and areas between ground level and DPC are subject to more severe exposure than the rest of the building.
This, coupled with the geographical location classed as severe or very severe, must be designed and constructed with due consideration.
Bricks fall into three durability categories.
F2 – Frost resistant – can be used in all normal building situations and degrees of exposure.
F1 – Moderately frost resistant, are also durable, except where they may remain saturated and are subjected to repeated freezing and thawing. Generally, they can be used between DPC and eaves although caution should be exercised on sites in elevated, exposed locations i.e. within close proximity to the seaside or buildings on high ground.
F1 rated products should not be used:
- Below ground level DPC.
- For cills
- For coping/cappings
- Beneath cappings
- In projecting details (plinths)
- In exposed site locations.
- In landscaping.
F0 – Not frost resistant – should not be used externally.
Note: Bricks with any of these ratings do not look different so ask your supplier for the rating.