Ornamental parquetry floors are some of the most spectacular and satisfying wood working projects that I have ever had the pleasure of teaching. Parquet floors have graced palaces and historic buildings for many hundreds of years. These are floors considered by many people to be the most beautiful wood floors in the world.
As president of the International Parquetry Historical Society, I have been fortunate to be afforded the opportunity to study these works of art from around the world. I have been fascinated by these ornamental wood floors since I visited my first palace twenty-five years ago.
Ornamental parquetry is a mosaic of wood pieces used for ornamental flooring. It is a project that does not require thousands of dollars worth of tools and the skills of a third generation master craftsman but yields spectacular results. What makes it even more satisfying to me is it can utilize small or damaged pieces of wood that may not be suitable for other projects.
Many parquet patterns have been named after famous places or people. For example, the Monticello pattern is based on the floors in Thomas Jeffersons home. The Louvre pattern is from the French Louvre Museum in Paris. There is an unlimited amount of patterns that could be used to design parquet floors. I have collected thousands of pre-existing designs which I use as inspiration for my own creations. When designing parquet floors, one is only limited by their imagination.
There are two classes in the United States that are dedicated to designing and fabricating ornamental wood floors. I spent two weeks this year helping teach the Expert class and also one week teaching the Advanced class at the National Wood Flooring Associations Headquarters. In these classes, students are given a few different species of wood for designing their floors. Their first task is to design a pattern for their floor. Many things are taken into consideration such as the size and character of the room. Another parameter for the pattern is that it has to be made from available material. For instance there could be five inch wide white oak, three inch cherry and two inch walnut available. The design would incorporate them into the most efficient and aesthetically pleasing pattern.
A simple crosscut sled is the key
A cross cut sled facilitates cutting the pieces for parquet patterns. A table saw crosscut sled jig is a simple solution to the problems associated with making parquet patterns. Many of pieces can be small and the crosscut sled helps keep your fingers away from the table saw blade. In addition, the cross cut sled produces very accurate repeatable cuts.
The parquet pattern for the project in is referred to as the Canterbury pattern. This pattern lent itself to the very small sized scraps of walnut that were available. The walnuts thickness was cut in half to double the square footage that the wood would cover.
The Canterbury pattern is elegant and elaborate but easy to install because it is made into squares. Many parquet patterns are composed of pieces of wood cut at 45 degree and 90 degree angles. Most sleds are set to cut 90 degree cuts. Another board will have to be attached to the sled to cut the pieces at 45 degrees. I attach an isosceles triangular piece of plywood which has two equal length sides. Align it to the blade at 45 degrees. I use two common speed squares to set my 45 degree angle to the saw blade then screw the plywood piece to the sled with a few sheetrock screws.
Making scraps into parquet
The wood to produce the parquet piece came from scraps of 2" strip flooring. The boards are fed through the table saw and cut in half to make two 5/16" thick veneers. The veneer strips are placed flat on the table saw and sawn into two pieces around 0.954 inches wide. This method of producing veneers can be used to replace damaged wood floors. A wood floor that had to be removed can be recycled into a 5/16" thick parquet floor. The broken tongues and grooves from this floor are not needed.
The veneer pieces need to be cut with repeatable accuracy. A stop attached to the sleds angle fence will provide firm support at the end of the veneer piece during cutting. Attach a stop to the right hand side of the angle fence. I cut a small groove into the right hand side of my plywood triangle fence and adhere an inexpensive combination square with five minute epoxy. This makes a movable and lockable stop and the metal ruler holds the strips in place during cutting. The first 1 _" of the metal ruler needs to be trimmed off with a hack saw to prevent it from hitting the saw blade. Cut the ruler prior to installing it. The ruler does not have to be trimmed if the scale is not going to be used.
After your parquet pattern has been designed and your prototype parquet tile perfected, the individual pieces of the prototype are used to adjust the fences and stops on your sled. This will ensure your cross cut sled is precisely set to make accurate repeatable cuts.
The veneer strips first angle cuts are done on the left side of the angle fence. The cut end of the veneer strip is then placed against the stop on the right hand side of the angle fence and trimmed to length. Just slide the sled back and forth over the table saw to cut the pieces. The sled is pulled back towards you and away from the blade to remove the finished piece. I place the different size pieces into separate boxes. I have one box with small separate compartments that I use when it is time to assemble the parquet tiles.
It is easier to install the pieces as fully assembled parquet squares rather than each piece by itself. You can use packing tape to keep the parquets together before installing them on the floor. I prefer gluing them to pieces of forty pound Kraft paper using a starch based wallpaper glue.
The most elaborate method is to adhere the parquet tiles to pieces of _" Baltic Birch plywood. The plywood pieces are slightly smaller than the parquet tiles itself. The parquet pieces are glued to the plywood using a urethane adhesive. PVA glues do work but require something like a vacuum press bag to ensure the parquet pieces are completely held down while the adhesive dries. A parquet tile made in this manner can also easily be inserted into the center of a normal strip wood floor as focal point.
To assemble the parquet squares, it helps to make a frame to hold them. All it takes is three boards attached to your work table. One side is left open to slide the finished parquet out. A piece of forty pound Kraft paper is put down first. Roll the starch based glue onto the Kraft paper. The pieces of parquet are assembled on top of the glue covered Kraft paper. When complete, slide out the tile and then the next one is ready to be assembled. The paper side of the parquet will actually be the top side of the parquet. A little water will remove the paper during installation.
Small things that could ruin the floor
It very disheartening to have problems with a floor after it is completed. Moisture related problems account for more than 90% of all wood flooring complaints. Your parquet wood should be within 4% of the subfloor moisture content. It is best install a wood floor with the moisture content of the wood and subfloor in the middle of the expected yearly moisture range of the home. Installing the wood too high on the moisture range will result in gaps in the floor during the dry season. Installing the floor too dry will cause cupping during the humid seasons. The U.S. Forrest Product Laboratory created map that indicates the expected average interior seasonal moisture range for different regions of the United States. The data provides a starting point to estimate what the expected moisture range might be for your project.
Parquet floors do not add any structural support to the floor. The subfloor structure should be above minimum design standards. I prefer to have double layer of plywood that is a total of 1 1/8" thick. The layers are installed perpendicular to each other with adhesive and fasteners. The sheet are fastened and installed in accordance with the manufactures recommendations. The clearance between the plywood sheets is generally around 1/8". Tongue and groove products may have this clearance already incorporated in their design.
To paraphrase, I install _" thick sheets of plywood perpendicular to the existing _" subfloor. I adhere the plywood using a urethane construction adhesive and fastened per manufactures instructions.
The subfloor should be flat within 1/8" over six feet. Flat does not mean level; flat means it should not have ups and downs like a roller coaster ride. A subfloor that resembles a roller coaster could create void areas under the parquet tiles. It would add a great degree of difficulty to sanding and finishing the floor. The ups and downs also change the distance across the floor from point to point. This will throw the pattern of your parquet floor off.
There are many ways parquet squares can be laid out. The main objective is to keep the parquet squares symmetrical with the walls. The focal point of the room may slightly change how the floor is installed. The parquet squares may need to line up with a focal point such as the stairs or a fireplace.
Borders or aprons can be added around the outside of the floor. A border is usually an ornate band of flooring installed on the outer peripheral of the floor. The apron is generally made from normal strips of wood flooring. This border serves as a transition for the decorative floor to the walls. The aprons and borders can add beauty to the floor and also help make the floor installation easier. The width of the border or apron can be adjusted to compensate for many design considerations. They can help hide walls that are not straight, reduce the number of parquet squares that need to be cut, help transition into another room or incorporate a focal point with the parquet floor.
Most rooms are not perfectly square. One or all the walls may not be quite straight. The difference that the walls are out can be split by adjusting the center line of the room. The center line of the room is found by measuring the width of the room at both ends and marking their centers. Use a chalk line to snap a line between the two points. The line that goes between these points will at the midpoint across the room and if a wall is out of square the difference will be split between the two sides.
Check to see if this line will work for the rooms layout. Place enough parquet squares to go across the room. The line can be adjusted if it saves cutting parquets at the wall. Perform any adjustments needed and then find the center of this line from the other two walls. Place a mark exactly in the middle between the other two walls on the main center line. This point can also be moved if it saves cutting parquet squares. If all else fails, remember there is a good possibility that the floor may look better with a border and apron anyway.
The parquet square requires two main working lines. The second line needs to be perpendicular to the first. There are many ways to do this but none work as well as the trammel point method. I do think lasers are fun to play with but trammel points are more accurate and cost less. Find a stick about as long as half the width of room. Drill two holes at one end of the stick (three to be safe) about a foot apart which are big enough to hold a pencil. Place a nail in the other end and tap into the subfloor at the point which has been determined to be the center of the room. Place the pencil in the closest hole and mark where the pencil crosses the first line at twelve oclock and six oclock positions. Remove the nail from the subfloor and tap it in at six oclock. Move the pencil to the hole farther away from the nail. The lengths of the arcs have to increase so they will intersect at the nine o clock and six oclock positions. Swing the pencil and mark an arc at the nine oclock and three oclock points. Remove the nail from the subfloor and tap it in at twelve oclock. Swing the pencil and mark an arc at the nine oclock and three oclock points again. Hopefully you moved the pencil far enough out on the stick that the arcs intersect. Snap a chalk line between the points where the arcs intersect at nine oclock and three oclock. This second line is perfectly perpendicular to the first.
The parquet squares can wander off course during installation. Snap a grid with a chalk line onto the subfloor. Each square of the grid should correspond to the size of the parquet squares. These lines will help you correct any deviations as they occur.
Install straight boards temporarily on the first and second center lines. They will be used as backer boards to keep your parquet squares straight during initial installation. The parquet squares will be installed in four quadrants. It makes no difference which quadrant is started first. Start in the center of the floor working away from the backer boards.
There are many types of adhesive sold for parquet floors. Urethane adhesives resist glue-joint failures caused from hygromechanical movements. In other words, urethane adhesives hold well over many years of floor expansion and contractions due to moisture changes. The adhesive should be applied as per manufacturers instructions on the container. The notches on the specified trowel meter the correct amount of adhesive onto the subfloor; so follow the instructions on the adhesive container or the wood floor might fall apart.
Be conservative with the size of the area that you first apply adhesive. Remove any adhesive that becomes stiff before you have a chance to install over it. The tiles are installed with the paper side up. Gently work the parquet square into the adhesive in such a way that adhesive is not caught between the edges of the parquet squares. Work the parquet square gently back and forth to assure they adhere properly. After a few tiles are installed, sparingly wet the paper on the parquet squares with a sponge or spray bottle. After approximately twenty seconds, pull the paper off the parquet and adjust any parquet squares or individual pieces that are not aligned. Remove any excess moisture on the parquet wood or it will distort.
Complete the first quadrant and remove one of the backer boards. The second quadrant will use a backer board on one side and the already installed parquet squares on the other side for alignment. Do not walk on parquet squares until the adhesive has set. Depending on the adhesive, this should be around eight hours. Leaving room for a border and apron will allow an access around the room while the adhesive is curing. In other words, do not parquet yourself into a corner.
Sanding & Finishing
In the past, sanding and finishing parquet flooring required the talents of an expert wood floor professional. There are now new machines that are available where the direction of the wood grain or differences in wood densities does not make a difference. I use a machine called a tri-planetary sander during the final steps of the sanding process. The tri-planetary sander helps flatten a floor to achieve a piano top quality surface.
The tri-planetary sander has three eight-inch disks revolving on one large disk that spins in the opposite direction. This machine aids in achieving flawless floors but it is almost impossible to find at a tool rental shop. Many home centers rent a machine called a U-Sand. The machine is basically four random orbital sanders combined together. These types of machines work well but are slower than using a large belt or drum machine. Many expert wood floor professions use tri-planetary sanders and multi-disk machines on parquet floors at the very end of the sanding process. When using any sanding machine, always try to keep the floor clean. Any abrasive grit or dirt left on the floor during sanding result in making scratches on the floor. Saw dust on the floor will hinder the effectiveness of your abrasive.