Concrete Vs Styrofoam Keystone

Though keystones no longer serve the structural purpose they were originally designed for, their presence has become commonplace in modern architecture. Styrofoam keystones coated with a cementitious product (to look like concrete) are easily installed into architectural mouldings, adding a focus point to the window or door surround, by breaking the trim into 2 halves instead of one monolithic piece.

Styrofoam Keystones on House
Styrofoam keystones provide a variety of advantages over traditional concrete keystones. Due to the lightweight nature of styrofoam, the product is transported and installed much easier. While a 12" styrofoam keystone may weigh up to 5lbs, a comparable concrete keystone will come out to as much as 50lbs. This means that not only is it more easily delivered, but it does not require structural support when being installed.

Pre-Coated Styrofoam Keystone
Along with styrofoam keystones' light weight, is a drastic reduction in costs. As mentioned, because styrofoam is lighter weight than concrete, transportation costs are lowered, and less engineering and material is required to install the product. The manufacturing process of styrofoam keystones also allows many more units to be made simultaneously than concrete keystones, further benefitting from economies of scale.

One of the most common questions is whether styrofoam keystones product will stand up to impact and abuse. The answer, simply put, is yes. The pre-coated styrofoam-core keystone is manufactured using an impact-resistant base coat, containing cement, fibreglass fibres and acylics. This combination provides high impact resistance, flexibility and durability. Beneath the 2 layers of this cement coating lies a fibreglass mesh to further reinforce the surfaces and prevent damage. The installation location of keystones must be taken into consideration as well; they are used over top of windows and doors, where there are not high amounts of pedestrian traffic.