Dutch Style Windmill
for
Lawn & Garden Storage

by Bill Cherry
January, 2000

In a backyard in North central Colorado, sits a very unique lawn & garden storage shed. It is a structure designed to resemble a Dutch or European windmill in outward appearance, while serving as storage for the lawn & garden tools and supplies used to maintain the surrounding lawn & flower beds.

Some Background Information...

Windmills of many different types have been in use throughout the world for a good part of recorded history. The type of windmill we know today as the European or Dutch windmill, was first built and used in Europe to mill grains, drain low lying areas, and to power other tools such as saw mills. The greatest concentration of these was probably during the 17th century, in the region known as Holland. The windmills in Holland had existed from about 1200AD, reaching a peak of approximately 9000 windmills in the 19th century. After this time, the number of windmills declined as the main tasks were switched to steam power and other types of power plants.

The types of windmills used in Europe varied greatly in size and style; but almost all were much larger than the "American" style of windmill or wind pump. The smaller windmills, such as the meadow mills and post mills were built such that the entire windmill and housing rotated to turn into the wind. But with the larger mills, this approach was not feasible. For these large mills, the main part of the windmill was stationary, with only the cap or "smock" turning into the wind. The smock or tower windmills often had a platform part way up the side of the windmill to allow access to "reef" the sails and control the brakes.

Often, the Holland drainage windmills would work in gangs to drain an area, with each group of windmills pumping the water to the next highest level; and the final set pumping the water beyond the dike that served as a barrier between the land and the sea. As an example, between the years of 1608 and 1612, the Beemster Lake was drained. This lake had a depth of 10 feet, and it was drained in one year with 26 windmills, working in two stages.

General Construction Details...

With the background above, we can see that this scale windmill project was intended to resemble the larger Dutch style, sometimes called the smock or tower mill, with a rounded cap. However, as this small structure is purely decorative, the head is fixed and does not rotate; and the sails are actually driven from the inside with an electric motor.

The entire structure is light framed construction, built from materials readily available at any home improvement center or lumber yard. The framing is done mostly with 2x4s & 2x6s and the siding is a composition siding with the appearance of lap board siding. One exception to this is the cap, where laminations of plywood are using for the framing members, to allow for the curved upper surface of the cap. This windmill is six sided, with all six sides, except for the front and back sides; which have the door and window installations. Each side was framed in 3 sections, the base section, the center or long section, and then finally an upper section. The following photos show the general framing details, and that of the cap. Note the use of plywood in the cap to allow for the curvature of the cap.

The need for the three framing sections described above is due to the taper in the sides at the various regions. The base framing section is from floor level up to the "waist" or widest point of the windmill tower. The center section goes from the top of this base section to the top of the windows, and then the top section on up to the top of the top. The cap sits on top of this final section, overhanging on the outside to provide the roof. A 2x6 is used at each corner to join the 6 sides. This 2x6 extends outwards enough to "frame" the siding, thus protecting the edges of the siding from the weather. The general dimensions & scale of the windmill are shown in this drawing.

Doors, Windows, & Trim Details…

As described earlier, the function purpose of this windmill is that of a lawn and garden storage shed. As such, it has two sets of doors and windows, installed in the front & back. The two sets of doors, allow a drive through arrangement for a garden or lawn tractor. Because, the height of the doors span the base region and part of the center region of the sides, they must be built with this same contour. This may proved to be one of the more difficult construction areas. The doors, front & back, are double doors, with a center latch. The center latch uses a pipe inserted (& removed from) slots cut into the door jam, in order to latch the doors tightly shut. Above each set of doors is a small window, to provide light to the interior.

In order to give the appearance of a platform around the windmill at sail height, a decorative platform was built on this windmill, with decorative tulips at each corner. The "platform" is supported by 2x2s rising upwards from the base section at each corner.

Details of the Sails…

The sails for this project are purely decorative and never intended to be driven by the wind. To the contrary, they are mounted to a central shaft which is driven from the inside by an electric motor. But this is not much different from some other restored windmills, such as the restored North windmill in Golden Gate Park in San Francisco. The four identical sails for this windmill are built from framing sections or ribs cut from 2x4s, with the leading & trailing edges being rounded 2x2s. Through the thickest part of the sail is a 2" steel tube, the same type as used in chain link fencing. These ribs are bolted into a wheel and shaft assembly, that extends into the cap of the windmill. The surface of the sails is covered with a plastic mesh material to give the appearance of the canvas and other sail material used on true windmills. Each sail is angled to give the appearance of a real windmill.

Drive Mechanism…

The central shaft of the sails extends into the cap of the windmill, supported by two bearings to support the weight and allow rotation. At the inner end of this shaft is a pulley driven by belt from an electric motor. The ratio of the pulleys is selected to allow the desired rotation speed and to provide the mechanical advantage necessary to turn the mass of the sail assembly. In addition, a lever shutoff is provided to allow better control on startup and shutdown (belt tension).

I'm sure there are many other ways to drive the sails if that is desired. This particular solution is presented as an example only; with the final solution left to the individual builder.

Additional Photos…

Here is the final appearance of the Dutch style windmill in it's setting within the yard.