How to avoid climate caused problems with wood furniture and Kitchen Cabinet Doors

23 January, 2014 BY JIM HILL

New home Cabinet Doors and remodeled homes with Replacement Cabinet Doors can face a difficult environment if relative humidity is left uncontrolled. Here’s why.

Ideally the woodâ_Ts moisture content in Kitchen Cabinet Doors will be matched to the average relative humidity of the region where the wood product will be used. This will allow the woodâ_Ts moisture content to be stable. When the wood moisture content and the local climate is closely matched, the finish on the cabinet door will keep the moisture content in the door from reacting too rapidly to relative humidity changes and, therefore prevent the damage those humidity swings could cause to an unfinished door.

Wood with moisture content of 7% is said to be at equilibrium (that is it wonâ_Tt take-on or give-off moisture) when relative humidity is at 30%. So wood with a moisture content of 7% will be stable when the humidity is 30%. As the relative humidity increases above 30% wood at 7% moisture content will absorb moisture, increasing the woodâ_Ts moisture content. When relative humidity decreases below 30% wood at 7% moisture will give off moisture. Itâ_Ts not the gaining or losing of moisture that is potentially damaging to wood products, itâ_Ts the speed of the change in moisture content. Unfinished wood will see the end-grain change moisture levels at a much faster rate than the center of the wood piece, and wood with large differences in moisture content across the length will develop significant internal stress. This internal stress can result in catastrophic damages, like cupping, warping, and even serious splitting.

Humidity is seldom constant and changes in relative humidity are certain. Thatâ_Ts where the cabinet doors finish offers protection. The finish is not intended to completely protect the door from the effects of humidity changes. But it is designed to slow the changes to the woodâ_Ts moisture content with the humidity fluctuations. When a rain storm approaches the relative humidity will spike but the finish on the cabinet doors will slow that high humidity from being absorbed into your doors so quickly as to cause damage. Moisture will still enter the doors, but before the wood moisture content is significantly increased, the storm will have passed and relative humidity will have returned to a point closer to the regions average level.

A more serious condition exists when an unfinished wood product has acclimated to a humidity level above 70%. If wood which has stabilized at this relative humidity is subjected to a very dry climate, with relative humidity levels around 10-15%, the high moisture content in the wood will boil-off very quickly. This condition where moisture leaves the end-grain faster than the moisture leaves the center (to replace it) is typically the major cause on end-grain splits. While end-grain splits are not even abnormal in hardwood lumber, that same end-grain split in the panel-cut of your Raised Panel Cabinet Door would be a serious defect.

The door styles most likely to show splits are Raised Panel Cabinet Doors. The area most susceptible to damage from rapid moisture loss is the end-grain on the raised panels. These panel cuts are where the panels are machined down from the A_-inch thickness in the canter to A¼-inch thickness where the panel tongue fits into the groove machined into the Rails. Splits caused by rapid moisture loss are common in these panel end-grains. Splits in the A_-inch thick panel center are much less common.

All traditional cope & stick cabinet doors have exposed end-grain on the stile ends which can show splitting with rapid moisture loss, although not as likely as the raised panel end-grain.

Mitered doors have the stile end-grain slightly protected because of their design so stile end-grain splits are somewhat less likely than in traditional doors.

Itâ_Ts important to remember that we are talking about the worst-case of an Un-finished cabinet door being exposed to an extreme climate change. While this perfect-storm of events is likely to damage unfinished cabinet doors, there is a preventive solution; Finish your cabinet doors as soon as they are delivered!

As a rule of thumb, wood products manufactured in a damp climate and shipped into a dry climate, unless finished very soon after delivery, have a high degree of potential danger, while wood products made in a dry climate can usually be shipped into a wet climate (or any other climate) with minimal likelihood of damage. This is because most climate-caused damage to a cabinet door comes from rapid moisture loss, and damage from rapid moisture gain is far less likely. That is one of the mail reasons we built our factory in Arizona. Arizonaâ_Ts dry climate allows our products to be shipped anywhere in the country with very little risk of climate related damage to the product.

The sealer and lacquer will slow the moisture migration, even in extreme climate conditions, to a point where your new doors will be a dependable, reliable, and beautiful addition to your home for generations.

When considering a location to place your unfinished cabinet doors prior to finishing, ask yourself this question; would this be a place I would store an expensive piano or other piece of fine wood furniture? Click here to get Laura Ashley voucher codes for amazing furniture.

Here is a Glossary to help clarify Woodworking Terms used in the Cabinet Industry

January 2014 by Jim Hill
Accessories – Supplemental parts of the cabinet referred to as bells and whistles. Any nonessential component such as rollouts, pullouts, tilt-outs, hardware, etc.

Angled Corner – Any cabinet type designed to fit on an end of an upper or lower cabinet creating a fixed angle.

Applique – A carved or etched decorative piece of wood installed on the face of cabinets. Also referred to as an on lay.

Base Cabinet – Any cabinet type designed to install directly on the floor. Some form of a top will be applied in the field, such as laminate, wood or granite.

BERP – (Base End Raised Panel) A decorative panel, usually matching the door style, designed to be applied to the side or back of a cabinet, an island for example.

Bevel – A portion of material removed from the edge of a piece of wood. This technique can be used to create a natural finger-pull such as on a beveled-edge door. Also is used to create a specific angle when two pieces of wood are joined together. For example, when two pieces have a 45A° bevel they create a right angle when joined.

Blind Corner – Any cabinet type, upper or lower, designed to install into a corner of a room. Another cabinet will install directly adjacent to it hiding the blind portion. This gives access to an otherwise dead corner providing more storage.

Bumper Pads – A small spongy material placed on any cabinet door designed to soften the noise as the door is closed.

Bun Foot – A round decorative furniture grade foot used on the bottom corners of base cabinets.

Butt Doors – Two cabinet doors covering a single opening, normally too large for one door. The edges of both doors nearly meet. The opening does not have a center mullion.

Butt Joint – A term used when the edges of two pieces of wood are joined together.

Cathedral Arch – A term used when the top cabinet door has a curved shape in the panel and frame.

Center Stile – A vertical strip of hardwood that is a component of the face frame. It usually divides a cabinet opening equally. Also referred to as a mullion.

Cherry – A moderately hardwood having a fine to medium uniform grain.

Close Grain – Having fine and closely arranged fibers or fine texture. Maple is considered to have close grain.

Color Variation – A natural variation of color inherent in any wood species. Soil type, mineral deposits, water levels, temperature and geographical location are all factors in the degree of variation.

Concealed Hinge – A term used to describe a cabinet hinge that is not visible from the outside. Referred to as a cup hinge.

Corbel – A decorative wooden bracket used as a support mechanism for mantels, bar tops, etc.

Corner Blocks – Any type of wooden, plastic or metal component used to strengthen any joint. Typical application is where face frame and end panel are joined.

Crown Molding – A term for any molding that is applied to the top of upper cabinets.

Custom Cabinets – Cabinets built to suit very specific needs. They are generally not limited to product lines, dimensions or design. They are typically more expensive but donâ_Tt necessarily offer the best value available in the marketplace.

Dado – A 1/4″ +/- deep channel or groove cut across the woodâ_Ts grain is called a dado. A dado joint is formed when a cross member is fitted perpendicular into the channel.

Dentil Mould – A term used to describe a decorative tooth-like pattern on any trim molding.

Door Styles – A variety of cabinet doors the consumer has to choose from when designing their home. Some styles are:

Arched raised panel (arch can be any of several arch designs)

Square raised panel

Arched flat panel

Square flat panel

Mitered raised panel

Mitered flat panel

Dovetail – A term used to describe a joining process of two pieces of material. Both pieces have wing-shaped notches that interlock. Generally known as one of the strongest joints typically used in furniture and cabinet drawers.

Drawer Face – Finished front panel of the drawer assembly. The profiles will match the door chosen.

End Panel – The panel forming the cabinet side.

Engineered Wood – A term used to describe several new types of construction material. Fiberboard, such as MDF and HDF, are more dimensionally stable than solid wood.

Exposed Hinge – A term used to describe a cabinet hinge that is visible from the outside. Some types are barrel hinges.

Face Frame – The front facing of a cabinet typically constructed of hardwood. The vertical pieces, called â_ostiles,â__ and the horizontal pieces, called â_orails,â__ reinforce the cabinet structure and provide mounting support for doors and drawers.

Fillers – Pieces of hardwood matching a chosen cabinet color. Sizes range from 1″ to 6″ wide and 30″ to 96″ long. Common use is to fill the space where a modular cabinet does not fill a specific wall dimension.

Finishes – A term for the surface treatment of a wood product to enhance the beauty of its natural wood color and grain definition. Usually applied in steps, such as stain, sealer and a clear top coat such as a catalyzed varnish.

Flute – A concave shallow groove that is routed into a wood surface. Fluting is usually applied vertically. Common use is to overlay on a cabinet stile or filler for a decorative effect.

Framed Cabinet – A traditional style of cabinetry. The box is built behind a picture frame-like structure on which the doors and drawers are applied.

Frameless Cabinets – Often referred to as European-style cabinets. Components, doors and drawers are applied to the inside of the box thus eliminating the traditional face frame.

French Leg – A furniture-grade decorative leg used on the bottom corners of base cabinets.

Full Overlay – Doors and drawers are sized large enough to cover the cabinet face with only minimal clearances between them.

Furr-Down – A box-out at the ceiling typically 12″ high and 14″ deep. Often used for AC ductwork. Kitchen cabinets are installed up to it creating a step effect. Also called a soffit or bulkhead.

Galley Rail – Any molding using tiny spindles to create a front retainer along a plate rail cabinet top. It gets its name because of its likeness to galley rails used on ships.

Grain Variation – A term used to describe a species of woodâ_Ts natural dissimilar grain pattern.

Hickory – A heavy, hard, strong, stiff wood with a fine uniform grain.

Hinge – A mechanical device used to attach a cabinet door to a cabinet box. There are many styles offering different applications, degree of swing and visibility.

Joint – A construction term used when two pieces of material are joined or attached together. Common types are:

Cope and Stick
Mortise and Tenon
Tongue and Groove

Kerf – A saw cut that is made on the surface to relieve stress. It is used to create a curve, such as with a toe kick around a curved base cabinet.

Kiln Dry – A term used to describe the process of oven drying fresh cut lumber. The process removes excess moisture so raw lumber can be fabricated into a finished product.

Knob – A hardware item, typically round in shape, attached to doors and drawers for function and decoration.

Knot – A hard node in any wood species where a branch once grew.

Laminate – v. A term used when layers of wood are bonded together through a process of heat and pressure. n. The plastic product used to fabricate kitchen countertops.

Lazy Susan – A corner kitchen base cabinet utilizing kidney shaped shelves rotating on a center poll for easy access.

Maple – A hard closed grain, light colored wood.

MDF – (Medium Density Fiberboard) A common grade of engineered construction material.

Melamine – A slick plastic-like material used to cover a substrate of engineered wood or MDF. This material is popular because it is durable and easy to clean.

Millwork – Any type of machined woodwork.

Mineral Streak – A discoloration in any species of wood caused by mineral deposits the tree extracts from the soil. Commonly seen as a blackish-blue streak within the grain.

Miter – A joint made when two beveled surfaces form a specific angle. For example, two pieces of wood each beveled at 22 1/2A° will form a 45A° angle when joined together.

Modular – A standardized increment of measurements specific to a product. Modular cabinets are generally manufactured in 3″ increments.

Mortise and Tenon – A specific joining technique. The mortise (groove or slot) is cut into a piece of wood. The joint is made when an opposing piece cut with a tenon (a collared protrusion) is slipped into the mortise.

Mullion Doors – Also referred to as a divided light door. The solid center panel is omitted and replaced with horizontal and vertical mullions dividing the open panel into smaller panels. Clear, smoked, bronzed, opaque or leaded glass inserts (provided by the consumer) can fill these panels for the desired effect.

Nomenclature – A string of letters and numbers used to identify specific cabinet types or accessories.

Oak – A durable open grained hardwood.

Onlay – A carved or etched decorative ornament installed on the cabinet face. Also referred to as an appliquAc.

Open Grain – Large pores or course texture in grain. Oak is an example of an open-grained wood. (See Oak.)

Overlay – Decorative panels affixed to a cabinet surface or attached to the ends of upper or base cabinets.

Peninsula – Similar in design to an island except open on only three sides. Often used in â_oLâ__ shaped kitchens as serving bars that separate the kitchen from the dining or family room.

Plywood – Multiple layers of wood veneer bonded by an adhesive forming panels of varying thickness.

Pull – A hardware item, usually crescent shaped, attached to doors and drawers for function and decoration.

Rabbet – A technique for joining two pieces at right angles. A portion of material is removed from the edge of one piece similar to the thickness of the other piece. When the two are attached the joint is strengthened. Also called a half-lap joint.

Racking – Generally caused by poor installation. The cabinet is twisted out of square resulting in poor door and drawer alignment and operation.

Rail – A horizontal door or cabinet frame component.

Reveal – The exposed portion of the cabinet face frame when the cabinet door and drawer are closed.

Rope Molding – A piece of molding milled to appear twisted like rope.

Rout – To drill or gouge out an area of wood for decorative or joining purposes.

RTF – (Rigid Thermo Foil) Used as a laminate in the process of fabricating a one-piece door.

Sapwood – Younger, softer outer portion of the tree trunk, just under the bark.

Scribe Allowance – Face frame extensions beyond the cabinet box for trimming to ensure proper fit.

Scribe Molding – A generic piece of molding, usually 1/4″ thick and up to 1″ wide, for the purpose of trimming and concealing any discrepancy where the cabinet meets a sheetrock wall.

Semi-Concealed Hinge – A term used to describe a cabinet hinge that is barely visible from the outside. Some types are called kerf or knuckle hinges.

Semi-Custom Cabinets – Cabinets built in 1/8″ increments, opposed to modular cabinets built in 3″ increments. Most have certain limitations in their product lines but are usually more flexible in dimension and design than a typical modular or stock cabinet product. They are typically more expensive but donâ_Tt necessarily offer the best value available in the marketplace.

Skin – A 3/16″-thick veneer panel generally used on the ends or backs of upper or base cabinets.

Soffit – A box-out at the ceiling typically 12″ high and 14″ deep. Often used for AC ductwork. Kitchen cabinets are installed up to it creating a step effect. Also called a fur-down or bulkhead.

Standard Overlay – A door style designed with a specific hinge type. The cabinet door overlaps the cabinet opening 1/2″ on all four sides.

Stile – A vertical door or cabinet frame component.

Stretcher or Nailer – A structural component of the cabinet box. They are hidden horizontal members connecting the end panels at back of cabinet. During the installation process 2″ to 3″ screws are used to mount the cabinet to the wall through the stretchers.

Substrate – The original surface or the structural material beneath the layer of veneer or laminate.

TERP – (Tall End Raised Panel) A decorative panel, usually matching the door style, designed to be applied to the side or back of a cabinet, a pantry or refrigerator end panel.

Thermofoil – A 100% flexible vinyl laminate that is applied to the substrate by using an adhesive or heat and pressure.

Tilt-Out Trays – A popular accessory item ideal for storing sponges and other dishwashing supplies. They are plastic trays attached to the back of false fronts at the sink area.

Toe Kick – The recessed area at the bottom of base cabinets usually 4″ high and 3″ deep.

Tongue and Groove – A specific joining technique, the groove is cut into one piece of wood. The joint is made when an opposing piece cut with a tongue (a collared protrusion) is slipped into the groove.

Valance – A decorative hardwood panel installed across an open area, generally used above desks or sinks.

Varnish – A hard, transparent coating used to protect the cabinet surface.

Veneer – A thin layer of wood (1/32″) of solid wood that is applied with an adhesive to a substrate.

VERP – (Vanity End Raised Panel) A decorative panel, usually matching the door style, applied to the side or back of a cabinet, a vanity end panel.

Wainscot – A wooden facing or paneling that is generally applied to a wall or large end panel of a cabinet.

Wall Cabinet – Any cabinet type designed to install at or above eye level. Common application is 18″ above the kitchen base cabinets. Also referred to as an upper cabinet.

Warp – Any wood product that distorts or twists out of shape. The general cause is excessive heat or moisture.

WERP – (Wall End Raised Panel) A decorative panel, usually matching the door style, applied to the side or back of an upper cabinet.