Why clinker and brick need attention
Clinker itself usually absorbs less than ordinary brick or concrete, but that does not mean the problem disappears. The most happens in the joints, which absorb water, collect dirt and are the first to turn green. Through them moisture gets into the masonry, and in winter there is the risk of frost damage.
The second typical problem is efflorescence, that is a whitish deposit on the surface. It is caused by salts migrating from the masonry with the water. Limiting water absorption helps reduce this phenomenon.
Efflorescence on masonry
The whitish deposit on clinker and brick is often a natural process, especially on new masonry. Part of the efflorescence goes away over time, to remove the rest you use dedicated products. Impregnation done on a clean, dry surface limits water getting in, which drives the formation of efflorescence.
Note
Do not impregnate masonry with fresh efflorescence or masonry that is damp after construction. First remove the deposit with a suitable product and let the masonry dry, otherwise you seal the problem under the protective layer.
Cleaning before impregnation
As with any surface, impregnation only makes sense on clean and dry masonry. Green deposits, dirt and streaks you remove with a product for the given surface, efflorescence with a product intended for it. Only then, after thorough drying, do you move on to protection.
Impregnating clinker and brick step by step
- 1Clean the masonry and joints. Remove deposits, dirt and efflorescence, paying special attention to the joints, which soil most strongly.
- 2Let the masonry dry thoroughly. Masonry and joints must be dry deep down, not only on the surface. After washing and rain wait accordingly long.
- 3Do a test. Apply the product to an inconspicuous spot to judge absorbency and a possible change in look.
- 4Apply the impregnation evenly. Spread the product on the bricks and in the joints, without gaps. The joints, as the most absorbent part, may need more product.
- 5Apply a second coat if needed. On absorbent masonry two coats are sometimes applied. The number of coats and the interval is on the label.
The most common mistakes with clinker and brick
- Impregnating masonry with fresh efflorescence or masonry damp after construction.
- Skipping the joints, which are the weakest point of the surface.
- Applying to dirty or overgrown masonry.
- Working in rain or just before it.
- Skipping the test on coloured or unusual clinker.
Frequently asked questions
Do I need to impregnate clinker if it absorbs little?
Clinker itself usually absorbs little, but the joints do. Through them moisture gets in, dirt collects and green growth appears. Impregnation, especially of the joints, limits these problems.
How do I remove efflorescence from brick?
Part of the efflorescence goes away over time on its own. The rest you remove with a product intended for efflorescence, according to its instructions. Only after removing the deposit and drying the masonry is impregnation worth it.
Does the impregnation change the look of the brick?
Water repellent impregnations usually keep the natural look, but on some surfaces they can slightly deepen the colour. It is best to check this with a test in an inconspicuous spot.
Does impregnation protect the masonry from frost?
It limits water absorption, and less water in the masonry means a lower risk of frost damage. It is an important help, but it does not replace the correct construction and drainage of the masonry.
