Timber Floor Cupping

As you can see moisture and wood don t go well together.

Timber floor cupping.

Cupping is a result of the changes in moisture in the room. Any wood floor can suffer from cupping. Leaks in pluming systems and fixtures sink dishwasher icemaker and toilet overflows. See the picture at the top of this post for an example of a cupped floor.

It ends up looking a little like an accordion. Wood cupping develops a set in boards ultimately boards that have cupped due to these moisture differences develop a set and remain cupped even when the boards have dried. If you imagine a picture of a child drawing a boat in the water then the water will give you a good idea of what a cupped floor looks like. When the moisture increases the wood swells and then when it decreases the wood shrinks.

Wood is hygroscopic so it gains or loses moisture in your home seasonally. Cupping is a common problem found in hardwood floors. This makes the wood appear to be in a u shape. Wet crawlspaces and basements will cup a floor as moisture moves upward.

This imbalance could either be moisture from the concrete environmental conditions in the space being to dry and drying out the top of the wood and or a wood floor that wasn t properly acclimated to the environment prior to installation. Cupping dry or wet wood floors can be caused by humidity lack of humidity temp water. There are a number of potential causes of site related wood floor cupping. The center of the board dips below the edges.

Cupping in solid wood floors. How our 950 moisture meter works is it has a hygrometer built in to read temp humidity and calculates your the emc equilibrium moisture content of what your wood floor should be. The simplest way to think of wood floor cupping is to imagine the edges of each plank sticking up higher than the centers. Cupping means that the wood that is raised on the edges of each individual floor board.

Cupping can also occur in rooms with dry humidity. Boards will remain cupped. Water vapor emissions from concrete. The paper will curl up away from the water.

They bow inward resembling the bowl of a spoon or the inside of a cup. Wood is hygroscopic in nature and thereby tends to absorb moisture from its surroundings causing problems in hardwood floors. Wet maintenance can cause cupping. As the name implies the surfaces of boards that suffer from cuppinghave a concave shape.

You can observe this dramatically in an interior wood floor that has been flooded then dried. It is not hard to see the effect in wood flooring either. The general effect is easy to demonstrate by putting a small strip of paper onto a small drop of water. The cupping is due to some type of moisture imbalance in the wood flooring itself.

Site related causes of wood floor cupping. Cupping occurs in solid wood flooring as a result of an elevated mc in the bottom of the flooring compared with the mc of the face.