You say Palladium, I say Palladian

A palladian window is a large window divided in three parts: a central sash that is arched at the top and two sashes on each side of it that are smaller than the central sash; the smaller sashes are rectangular, topped with flat lintels.  This style of window is also called a palladium window depending on where you look on the internet.  Needless to say, this window is very common in the D.C. metro area with some of the production home builders like NV homes, Winchester homes, Pulte homes, and Toll Brothers.  The challenge for a bricklayer is how to cross over this style window with a brick arch.  Cast stone commonly is used.

Here is a palladian surround we did for Plus One Masonry @ Pulte homes.  As you can see the lines are clean and the look maintains it's colonial architecture.  There are several examples of historical palladian/colonial buildings in Annapolis Maryland one of which is the Hammond-Harwood House

And a modern example in Baltimore is a multiple building project at Johns Hopkins University for Henry J Knott Masonry.  Here it is 3D google maps.

Getting back to the residential palladian window, here is the design we use for a brick arch.  There are two  tricks to making it look good in my opinion.  First is how the radial arch and the lintel jack arch come to a natural meeting point on each side of the 1/2 round window. Second is to avoid small brick pieces if possible.  You do this by starting with a 7" long radial brick, and by the time you are to the 5th course on the 1/2 round center, the bonded arch meets up with the bonded lintel wing.

My vote is for calling it a palladian window.

Cast Stone Arch

Chuck of Oswald Masonry placed an order for jack arches, sills, and radial arches made of cast stone for a 5 unit townhouse. Cast stone or precast is a concrete product that essentially is man made limestone. We fabricate cast stone in our shop using raw materials in a mix of approximately 70% sand, 20% portland cement, 10% water, and less than 1% admixture of superplasticizer and water reducer. Here are pictures of the stone starting at the CAD design.

full scale paper template

template made into a wooden mold


We use the dry tamp method to make our cast stone at Archway System. Dry tamp uses zero slump concrete (the consistency of pancake mix if you only used half the milk the recipe called for). We make a custom mold of what the finished stone is going to look like and add the mix into the mold. We then use a vibrating rammer to tamp the mix into the mold face down. Epoxy coated rebar is inserted in the middle of the stone for reinforcement and then more mix is added and tamped until the desired thickness is achieved. The mold is then flipped onto a table and the mold is removed.

stone flipped out of mold



The stone is then "pointed up" by hand to fix any imperfections that happened when removing the mold. Then the mold is put back together and the process repeated all day long.

5 cast stone arches


Cast stone cures in warm temperature and high humidity on these tables and is about 95% cured after 7 days. The arches are rock solid after a few days and the brick layer installs the cast stone above the windows.

Maple Lawn in Howard County Maryland/Oswald Masonry