Warm weather can make concrete repair more challenging. Higher temperatures, direct sunlight and warm mixing water can all accelerate the setting time of cement-based products, reducing working time and increasing the risk of poor application.

For contractors working in civil engineering, water infrastructure, construction, rail and general concrete repair, preparation becomes even more important during hotter periods. Materials should be stored in a cool, shaded area before use, and clean, cool mixing water should be used wherever possible. Teams should also avoid leaving bags, tools or mixing water exposed to direct sunlight before application.

Where practical, work should be planned for the coolest part of a given day, typically the early morning. Smaller batches can also help users maintain control, particularly on detailed repairs or larger areas where finishing time is important. Substrates may need appropriate preparation to manage suction, and freshly applied material should be protected from direct sunlight – as this causes moisture evaporation and cracking.

Natural Cement also offers product options to support warm weather working. NATCEM® RETARDER is designed to slow the setting time of our products, helping extend workability when temperatures rise. This can be particularly useful where warm conditions would otherwise accelerate the set.

For applications where a naturally slower-set product is more suitable, NATCEM® TANK and NATCEM® DW can provide practical alternatives to NATCEM® 35 and NATCEM® AC. NATCEM® TANK sets in approximately 55–60 minutes, while NATCEM® DW sets in approximately 40–60 minutes. However, warm weather and warm water in the mixing process can still accelerate setting times, so good site practice remains essential.