As UK temperatures rise, are your waterproofing installations at risk?
Whether you're laying membranes, applying resin coatings, or using cementitious grouts, the hotter months being challenges that can compromise the performance of waterproofing and gas protection systems if not managed correctly.
This guide is designed to help site teams, contractors, and installers adapt to higher temperatures and maintain quality, compliance and performance across all Premcrete system installations.
Why Does Hot Weather Matter?
Extreme temperatures can accelerate cure times, soften adhesives, or increase the movement of materials. If these conditions aren't factored into your installation process, it can lead to:
- Membrane movement or deformation
- Reduced adhesion to substrates
- Premature curing and wastage of product
- Long-term failure of your waterproofing or gas protection system
Let’s break down how to prevent this for some of our most commonly specified systems.
1. Combi-Seal and Combi-Seal Plus
These membranes are manufactured with advanced MS Polymer and APAN™ fleece-bonding technology. Under rising temperatures, the membranes may move slightly due to retained moisture in the polymer matrix. Here's how to maintain system integrity:
- Mechanically fix lap joints through the area where HCR Butyl Tape has been applied.
- If fixings are made outside taped zones, apply Twinseal Compound GR to preserve gas tightness.
- Fixing to blinding concrete? Use Premcrete Metal Washer fixings at 500mm centres.
- Fixing to clay heave board? Staple at the lap joint using a heavy-duty staple gun at 200mm centres, and lay reinforcement spacer blocks to hold position.
2. Maxiprufe Plus
Premcrete's Maxiprufe Plus self-healing membrane can tolerate mechanical fixings throughout, but in high temperatures:
- Focus fixings along lap joints to ensure locked sheet integrity.
- Use appropriate fixings based on substrate (nails or staples).
- Reinforcement spacer blocks should always be used along laps for consistency.
3. MMA Resin Systems (Eponite MMA, Epocote MMA, Eposcreed MMA)
MMA systems cure rapidly – and that’s a challenge in summer heat:
- Pot life can drop to just a few minutes in direct sunlight.
- Apply during cooler hours when possible (early morning or late afternoon).
- Mix only what can be immediately applied.
- Spread product quickly after mixing to reduce internal heat build-up from exothermic reactions.
4. Hydroprufe 3000/8000 Membranes
These self-adhesive bitumen-based membranes are sensitive to heat:
- Exposure to high temperatures can soften the bitumen and weaken adhesion.
- Always ensure full support on vertical applications.
- Avoid leaving membranes exposed before backfilling.
5. Cementitious Mortars and Grouts
Hot weather causes rapid moisture loss, leading to shrinkage and cracking:
- Always ensure proper curing – avoid exposure to direct sun.
- Use a high-efficiency curing agent like Envirocure 90 (90% efficiency) to retain moisture and prevent premature drying.
- Consider shading or covering if curing outdoors in peak temperatures.
Summary Checklist for Hot Weather Installation
✅ Always follow product-specific fixing guidance
✅ Avoid midday installation where possible
✅ Use proper curing agents and reinforcement accessories
✅ Contact technical support if in doubt
Need Site-Specific Advice?
Premcrete’s technical support team is here to help you get it right the first time. Email us at technical@premcrete.com for tailored advice on product use in summer conditions, or to request a toolbox talk or on-site installation guidance.
Don’t let the sun compromise your substructure. Waterproofing is futureproofing — but only when installed right.