» Installation of edge-grain solid wood tops

For a long-lasting, great-looking kitchen countertops, bar tops, butcher block counter tops or kitchen island tops, some specific directions concerning storing, installation and maintenance must be followed. Failure to comply with the prescribed procedure might trigger damages that are not covered by our warranty. 

Storing and handling

Ideally, boards should be stored flat against the ground. If the boards are to be stored on level supports, please ensure the supports are evenly distributed along the board. In a tight space, you can also store the boards leaning against the wall at a pretty sharp angle.
Do not store the boards outdoors, in an excessively dry or moist environment, or near a heat source.
We also recommend that the protective plastic sheet not be removed too long before installation and cutting. Large wooden tops are usually quite heavy, so please handle them with care, to avoid injuries and damages to the product.

 Finishing the wood countertop 

A large variety of finishes can be successfully employed in order to grant your wood top protection, enhance its beauty or create special effects. Varnish, lacquer, shellac, wax, oil, natural resins and wood stains can each constitute the best finishing choice under certain circumstances.
Largely, if the food were to be prepared directly on the wood top (which is, you will cut and chop food directly on the wood top, without using a cutting board), then the mineral oil would be the most recommended finishing type. 

If the top is mainly a dining area, or if you’ll use cutting boards when cooking, then a polyurethane-based varnish would be greatly preferred, as it offers a better overall protection.
Regardless the finishing type, the solid wood tops should be finished after the shaping/ trimming is done and prior to installation.

Oiling the top 

The mineral oil finishing allows you to use the wood top as a large cutting board or a similarly large food preparation area. It is a penetrating finishing, versatile, easy to apply, inexpensive, yet offering fairly good overall protection. Whenever the wood surface gathers too many scratches and cut marks, you can make it look new again by sanding it gently and re-coating with oil.

Our company supplies the Proterra 11066, a food grade mineral oil, an ecological, biodegradable product specially designed for this type of application. Alternatively, you can use linseed oil, walnut oil or tung oil. The later two will also darken the wood. Most drugstores also sell generic, clear-colored food-grade mineral oil that can be successfully used as a wood finishing. In order for the mineral oil to seal the wood pores effectively, it must be applied correctly. Please follow these instructions: 

• Using a clean paintbrush, apply the oil abundantly onto the wood surface. Insist on the end-grain area, where the pores are wider and the wood is more prone to absorbing moisture. Make sure the oil is applied evenly on both sides of the wooden top. 
• Let the wood absorb the oil into its fiber. Depending on the wood type and the environmental conditions, this process can take between 1 and 6 hours. The Proterra oil we supply is one of the fastest absorbing oil finishing. If you choose to use tung oil, teak oil, or walnut oil instead, please note that these products take usually longer to cure. 
• Repeat the process for a second coat of oil. Allow drying, and then apply the third coat. At this point, the wood should be soaked in oil and you should allow it to dry overnight. 
• Remove the excess oil with a paper towel or a clean cloth and your top is ready for installation. 

Please be advised that, after the installation, the top side should be periodically oiled (once every month during the first year and at least twice a year ever after). Also, please note that mineral oil will not protect the wood very well against food marks and water splashes marks. You can however, significantly improve its water repelling and stain deterring properties by mixing equal parts of mineral oil and beeswax and here is how: 

• Heat the mineral oil in a metal can. Don’t overdo it, though; if the oil starts smoking, you heat it too much. 
• Slowly add the beeswax and stir the mixture while heating. Please use caution, as this mixture is highly flammable. 
• When the mixture is homogenous, pour it on the wood surface and spread it evenly onto it using a clean paintbrush. 
• Remove the excess with a dry cloth before the mixture starts drying up.
•  After the mixture is cured, polish the surface using another dry, clean cloth.
•  Dispose the clothes in a sealed bag or container after use. 

Varnishing the top 

A varnish finishing will not allow you to cut or chop directly on the wood top, but instead, will provide a superior protection to the wood without requiring periodic maintenance and subsequent re-applying. The varnish is especially strongly recommended whereas a lot of moisture is implied (such as bathroom vanity tops or the immediate vicinity of the kitchen sink). In this kind of situations, the mineral oil does not offer a full protection, so mold and black stains can eventually appear.

Ideally, the varnish should be applied with professional equipment operated in a special environment by knowledgeable personnel. Nevertheless, you can get comparable results at home, with only a paintbrush and a bit of skill. For countertop applications, water-based and polyurethane-based varnishes are the most common options. Regardless the type, however, the finishing process follows common guidelines. 

• Always apply the varnish in an environment as dust-free as possible.
•  Always apply the varnish only with a new, clean, natural bristle brush.
•  Always use new varnish; the varnish that has been already used several times will surely contain small lumps of dried varnish. 
• Always use a varnish with a very good self-leveling ability. You can test that on a piece of scrap wood before starting the finishing proper. The bristle marks disappearing shortly after the brush stroke proves a good self-leveling capacity. 
• Apply the varnish with smooth and long strokes, along the grain.
•  Allow drying; depending on the varnish you use, that can take up to 24 hours. 
• Gently sand the finished area with a fine sanding pad 
• Remove the resulting sanding dust with a moist cloth and allow drying.
•  Re-apply a second coat and a third one, if necessary, using exactly the same steps.

Attaching the top to the cabinet box 

The solid wood top must be attached to the cabinet box using only wood screws and washers. Do not glue the top on the cabinet box. The top and the box expand and contract at different rates, therefore cracks might eventually appear, most probably on the cabinets' surface.
The proper way of installing a solid wood top is using metal fixings along the cabinet box, as shown in the drawing on the right.

The metal fixings must be uniformly distributed throughout the length of the top, spaced at a 1' - 1.5' distance from each other. Across the width, the top is usually fixed to each metal support with three screws, one in the middle, one toward the front edge and one toward the rear edge. The supports must be perfectly leveled; otherwise tensions can develop in the wood, leading to warping, cupping, or cracks.

We recommend pre-drilling the screw holes into the wood countertop, in order to avoid cracks and splits. For the same reason, it is a good idea not to over tighten the screws. Wood displays natural movements, usually following changes in the environmental humidity.
The finishing will considerably diminish the extent of such movements, but will not eliminate them altogether. Due to the panel's laminated structure, the lengthwise movements are negligible, so the installer should pay attention to the movements occurring across the panel's width.

In order to prevent the development of inner tensions, the holes in the metal fixings should be elongated in the direction of the movements (see picture). When the rear edge of the counter top is installed against a wall, the wall might restrict the top's natural movements, leading to undesired tensions in the wood. To avoid this, you can allow a 5-10 mm joint between the wall and the countertop edge and caulk it with a thin bid of acid-free silicone.

Additionally, you can firmly fix the rear edge to the metal supports underneath and thus, allow the natural movements to occur at the expense of the opposite edge. In this case, the holes in the metal fixings corresponding to the rear edge will be no larger than the screws diameter, while the holes corresponding to the middle section and the front edge will be elongated as previously shown.

Joining two sections of solid wood surface 

This is a pretty straightforward operation that can be easily done by press-gluing the boards. All you need is a good adhesive and a perfectly flat surface. If the total width is not too big, you can press the boards using clamps; alternatively, you can use tighten bolts and washers attached on the bottom side, as shown in Drawing #2.

The panels' edges are straight, at a perfect straight angle and the lamellas all have the same width. Consequently, if the boards are pressed properly, the seam will be invisible. After the seam is cured, the gauge hiding the bolt can be covered with silicone caulking. Additionally, a few biscuit joints along the seam will grant extra stability. 

Sink inserts 

A sink insert is usually associated with increased moisture, therefore, regardless of whether the sink is over mounted or under mounted, the edge grain of the sink cutout must be carefully sealed, using a polyurethane-based varnish, as mineral oil finishing might not always grant the necessary protection for this area.

Ideally, the whole portion of countertop supporting the sink should be finished with polyurethane-based varnish. The sink's edges must be caulked properly, in order to prevent water infiltration between the sink and the wood surface. For configurations stipulating multiple sinks, the distance between them should be kept to at least 8". 

Dishwashers underneath the countertop 

If dishwashers are installed underneath a solid wood countertop, an aluminum foil must be applied to the bottom side of the top, in order to give additional protection against heat and moisture. 

Unsupported ends 

We do not recommend allowing unsupported ends longer than 1.5'. The average specific weight of the hardwoods species we promote is about 46 lb/ cubic foot, so the unsupported section might, over time, bend under its own weight.