There are many Allan Block retaining wall cap options, each with their strengths and weaknesses. First, I’ll give you an overview, then application specific strengths an weaknesses.
The 12” wide caps are available in the classic style and come in grey and charcoal color. They are lighter to work with, and curve the tightest. Their main strength is the smoothest in which they curve. The narrower the cap, the smoother curve they can be made into. These are the narrowest cap Allan Block makes.
Their big drawback is they do not make nice 90-degree inside or outside corners. Because they are 12”x12” when you cut a 45-degree angle one side ends up being too short to make a nice 90-degree corner.
18” wide classic caps are available in both Grey and Charcoal. These are best used when there is a retaining wall that has straight sections as well as curves. Pairing the 18” wide cap with an 18” wide block allows you to offset the seams (running bond), and strengthen the wall. A cap glued to 2 blocks will help lock the top row together much better than gluing 1 cap to 1 block.
The wider the cap is, the less pieces you need to install, this is why contractors often choose to use a wider cap.
So far, we have been talking about the classic style caps. These are available in both the 12 and 18” caps. The classic style is a simple split face look. New to the market is the PRO MAX cap.
The PRO MAX cap is only available in 18” wide, and comes in both grey and Charcoal. This cap has a higher appearance, and a beveled edge on either side. It looks great, and compliments the block with the same beveled edge. This PRO MAX cap was designed to allow room for retaining wall lights to be installed under it shining down on the retaining wall.
On straight walls this cap looks, and functions great. Gentle curves can be made, however tight curved walls are very tedious to make. Several cuts have to be made under the cap to allow it to “CLEAR” the lip. In general, this cap shines on straight walls, but is not ideal for tight curves.
When placing caps on a curved wall wedges are cut on each side of the cap to make the cap curve with the wall. The Pro Max cap has a nice bevel on either end of the cap and when you cut it off, you lose this look. Outside curves are not affected by this, but inside curve are. This is not a huge issue, but the look will be slightly different. Fortunately, most people will not notice this.
The color variations between styles do not match. A 12” Charcoal cap will not be the same color as an 18” charcoal cap. Even the greys between classic and Pro Max are different.
A trained, certified, and experienced Allan Block installer will choose the right style and width of cap for your project, all you have to do is choose between grey and charcoal!