Everbuild 402 Water Seal 5L

In-Depth Look

Rain soaking into porous masonry on exposed walls can add to damp problems. Everbuild 402 Water Seal reduces how much water soaks into brickwork without noticeably changing its appearance. It does not cure existing damp or fix defects such as cracked render or failed pointing, so deal with those first.

How It Works

The product is a clear liquid that soaks into the pores of masonry rather than forming a surface film. Once absorbed, it makes the surface water-repellent, so rain beads on the surface. Because it sits within the pores, it does not leave a glossy or wet-look finish. The treated surface remains breathable, so moisture vapour from inside the wall can still escape.

Application and Coverage

Apply to dry or damp (not wet) masonry using a brush, roller or low-pressure garden sprayer. Two coats are recommended, with the second applied within about an hour while the first is still wet. Coverage varies with how porous the surface is, so check the label and allow enough for two coats. It is for outdoor use only.

Summary

Everbuild 402 Water Seal is a clear, breathable silicone resin based water repellent for exterior brick, stone and render, applied in two coats wet-on-wet.

How It Compares

Everbuild 402 Water Seal is a transparent water repellent for mineral surfaces such as brick, stone, render and pebbledash. It is silicone resin based, contains no harmful solvents and is non-flammable. Water beads on the treated surface, and the surface is described as still breathing, so moisture vapour can evaporate. It may be applied to dry or damp surfaces, but not wet ones, using a brush, spray or garden sprayer. Two coats are recommended, with the second applied within about an hour while the first is still wet. It is for outdoor use only. Check the label for coverage.

A water repellent reduces the water entering a surface. It does not repair cracks, failed pointing or gutter faults.

For gaps and cracks, see the Everbuild Weather Mate sealant. The 1200 gauge damp proof membrane is below-ground damp protection, which is a different job. Our guide to choosing building materials has more.

Common Questions

What does a water repellent do to brickwork? Water beads and runs off, and the wall can still let vapour out.

Can I apply it to damp walls? The maker says dry or damp but not wet. Do not apply in rain or frost, and check the label.

Will it change how the wall looks? The maker describes a clear finish. Test a small area first.

Does it cure damp? No. It reduces water soaking in. Fix leaks, cracks, pointing and gutters first.

How many coats? Two, with the second coat applied within the hour while the first is still wet, according to the maker.

Is there anything to protect? Wear gloves and eye protection when spraying, and protect plants, glass and nearby surfaces. Follow the manufacturer’s instructions and use a competent person where required.

What surfaces is it for? Mineral surfaces such as brick, stone, render and pebbledash. It is for outdoor use only. Check the label for coverage and for the surfaces it suits.

How do I apply it? By brush, spray or garden sprayer. The label gives the rate to apply, so check it before you start.

A water repellent does not deal with the cause of a leak. Look at gutters, pointing and cracks around the wall, since water entering through a defect can keep entering whatever is on the surface.