When we think of construction challenges in the UK, rain and cold often come to mind — but don’t be fooled. Hot weather brings its own unique set of issues, especially when it comes to working with certain construction products. As summer temperatures rise, products can behave unpredictably, application windows can shrink, and both materials and workers are put under added stress.
From faster curing times to reduced workability, hot conditions can affect everything from cementitious materials to sealants, resins, and coatings. What works perfectly in spring can become a race against the clock in the hotter months. That’s why it’s crucial to adjust your approach when the mercury climbs — not just to maintain quality, but to protect your workforce and stay compliant with safety standards.
In this guide, we’ve rounded up the most important hints and tips to keep your projects on track when things heat up. Whether you’re on a busy city site or a remote rural project, these practical pointers will help you work smarter and safer all summer long.
Watch Your Water Ratios
Tip: Don’t overcompensate with water.
In hot, summer weather, mixes can dry faster — which tempts many to add more water. But this can be a critical mistake. Overwatering weakens the product, reduces durability, and can lead to cracking, dusting, or delamination.
Instead, use admixtures designed for warm-weather use. These can improve workability without compromising strength or longevity. Always follow the technical data sheet (TDS) for guidance.
Also cooling mixing water for cement based products can lower the initial temperature of the product
rbs Flow Plasticiser
An economical high performance water reducer based upon polycarboxylate ether, it is designed to improve the workability of the concrete with minimal effects on other properties. Reduced shrinkage, increased early and final strength.
rbs SBR Bond
A water-based non-ionically stabilized hydrolysis-resistant dispersion of a carboxylated styrenebutadiene copolymer. The dispersion is freezethaw stable. At higher temperatures (>25°C) the addition of rbs SBR Bond prevents a premature stiffening of the mortar.
rbs Greentard Liquid TF
An aqueous biodegradable top face retarder for application onto freshly placed horizontal concrete to produce an exposed aggregate surface. It is excellent for receiving subsequent concrete or toppings and also to give decorative finishes.
Store Materials & Equipment in the Shade
Tip: Keep products and equipment cool before use.
Leaving bags of cement, tubes of sealant, or drums of resin in direct sunlight can raise internal temperatures dramatically — which shortens pot life and affects application properties. Some materials may even start reacting inside their packaging.
Store products and equipment, especially the mixing equipment in a cool, shaded, and dry areas — ideally indoors — and try to bring only what’s needed to the working area. Cover pallets with reflective tarps or canopies if storage space is limited. Always read the storage instructions for products carefully.
Surface Temperatures Matter
Tip: Check that substrates aren’t too hot to work on.
Surfaces like concrete, asphalt, or metal can absorb and retain heat, sometimes reaching over 50°C even if the air temperature feels moderate. Applying coatings, adhesives, or repair mortars onto superheated surfaces can cause rapid curing, bubbles, or bonding failure.
Always check surface temperature before application — not just ambient temperature. Infrared thermometers are inexpensive and extremely useful for this purpose.
rbs Bluecure R90
Is formulated with solvents and inert hydrocarbons and is designed to provide a fast drying, flexible, tough and impervious high efficiency membrane that protects the concrete surface from rapid water evaporation during the initial curing stages.
rbs Greencure Sealer
A ultra low odour single pack white polymeric aqueous emulsion designed to impregnate concrete surfaces thus acting as a curing aid, surface sealer, dustproofer and hardener.
rbs Greencure Super
A spray on temporary membrane to retain moisture in freshly placed concrete. It is formulated to prevent evaporation of the gauging water and provides an efficient method for curing concrete. Gives reduced shrinkage and cracking and creates a more durable, hard wearing surface.
Keep an Eye on Open Times
Tip: Act fast — open and working times shrink in the heat.
Many products have an “open time” that shortens significantly in hot conditions. For example, epoxies may set faster, or cementitious grouts may become unworkable sooner than expected.
To avoid waste and rework:
- Only mix what can be applied within the adjusted working time.
- Use smaller batch sizes.
- Have all tools and team members ready before mixing begins.
Resapol’s technical team can often provide summer specific advice, so don’t hesitate to reach out.
Hydration and Team Safety
Tip: Shift working hours earlier to avoid peak midday heat.
Shifting work schedules to start earlier in the morning helps avoid the peak midday sun. This not only reduces physical strain on your team but also means that temperature-sensitive materials — like resins, coatings, and cement-based products — can be applied in more stable conditions.
Early starts can reduce the risk of flash setting, help materials cure more predictably, and minimise the chance of surface defects caused by excessive heat or direct sunlight.
Tip: Keep your crew cool and hydrated in the summer.
It’s not just the products that need care — your team does too. Provide shaded rest areas, regular water breaks, and watch for signs of heat stress. Don’t forget to apply suncream if working outside. Safety first, always.
Consult Resapol
Tip: When in doubt, ask.
Hot weather can dramatically affect performance — especially for specialist materials – some may be suitable for warm weather, others may require different curing techniques or special primers. If you are unsure, speak to the manufacturer or your local Resapol technical expert for tailored advice. We will be able to help with alternatives, accessories and best practice techniques tailored to your site conditions.
Summary
Hot weather might be a welcome change in the UK during the summer — but it still calls for smart planning, proper storage, and product-specific know-how. Follow these tips to maintain high standards, protect your materials, and keep everyone on site safe.
Stay smart, safe and make the most of the sunshine.
Resapol are here to support you whatever the weather, with excellent technical advice and same / next day delivery on a large number of products. With our depots strategically situated across the UK, so shipping to you is both quick and efficient.