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FAQS - Retaining Walls

Why should I use Allan Block for my landscape project?

For more than 20 years Allan Block has made it easy to Plan, Design and Build landscape walls of distinction. Allan Block has a solution for almost any landscape application. View the Allan Block publications Landscape Lifestyles and Landscape Walls Installation Manual for some great ideas.


How high of a wall can I build with Allan Block?

Allan Block walls have been built over 40 feet in height (12.2m). More practical landscape walls, 6 feet in height and under (1.8m), are made easy by following the Allan Block publication Landscape Walls Installation Manual or the Allan Block Installation Guides.


Do I need a concrete footing for the blocks?

No. Allan Block is designed to sit on a compacted granular base. This saves time and money while providing a solid base for the blocks. See the Landscape Walls Installation Manual for the recommended depth and width of base for your wall.


What is that white stuff on my retaining wall blocks?

Occasionally, some blocks may have a whitish residue upon them. The whitish colored residue is called efflorescence. Efflorescence is a natural by-product from the cement hydration process and can be found in any concrete or mortar product. Calcium oxide inside the paver reacts with water in the capillaries and forms calcium hydroxide. This seeps to the surface and reacts with the carbon dioxide in the air to form calcium carbonate, a whitish residue. When moisture on the surface evaporates, the white efflorescence becomes visible.

If efflorescence is present, it will wear off over the course of time with traffic and the elements. If you wish to speed up the removal of efflorescence, Calstone recommends the Aldon Paver Restore.