TAKE CARE OF YOUR MAC
Here is where you'll find advice and ideas on everything from weather exposure, oiling and what's in a log. This info is based on years of experience working with cypress timbers.
WHAT'S IN A LOG
Macrocarpa and Cypress timbers are well known for their natural durability. Naturally, under the building code, our Heart Mac is durable to H3.1 (equivalent to treated radiata pine). This means it can be used for above ground, external applications like cladding and fascia.
The logs them selves have very little sapwood in them. Sapwood is the outer layer of new wood that forms just under the bark. In mac the sapwood ring is very small and this means that most of the log can be used for heartwood applications. Mac Sapwood is also resistant to borer in a natural state and is widely used in areas where this is a serious problem.
Heartwood is defined as ''the inner layers of the wood, which, in the growing tree, have ceased to contain living cells, and in which the reserve materials (e.g., starch) have been removed or converted into heartwood substance" (IAWA 1964, p. 32). In some species, heartwood may be distinguished from sapwood by a darker colour, lower permeability, and increased decay resistance.
OILING, TINTING, PAINTING
There are many options for protecting your timber, however we recommend oiling the timber, regardless of its application. Why?
When the timber is sawn and put into exposed conditions, if the timber dries too quickly it may check/crack. While this occurs in the natural drying process, we want to prevent it opening up too much.
Oiling the timber is like conditioning or moisturising your face in the morning. It keeps the timber from drying too quickly and helps bring out the grain in the timber. It also protects and repels water.
Painting our timber is perfectly ok, but beware of dark colours. Ensure that dark colours don't absorb too much heat from sunlight as this can cause the timber to dry rapidly.
Tinting. Also part of this protection of the timber you can choose from a wide variety of colours and tints. We stock the following products and are able to pre-oil these products to save you time.
CHECKING AND SHAKE
Checking and shake are terms used to describe the natural cracking that occurs in the timber. While we work hard to prevent checking and remove shake, it's important to understand that they are simply part of the nature of the timber product.
Shakes are natural occurring defects in standing trees caused by a lengthwise separation of latewood fibers. Shakes were once thought to be caused by external stress factors such as wind and temperature extremes (often called wind shakes); however, research has found that a bacterium is the true cause of shake. Reference
Checks occur due to the top layers of the timber drying to rapidly. At MacDirect we take care to ensure we dry our timber over a minimum of 4 weeks, both air drying (out of direct sunlight) and kiln drying.
While we can't 100% prevent checking we aim to minimise it. See the oil section to see how to best protect from checking
Dry Timber: We supply dry timber at 16%. So it's important to allow your timber to acclimatise in the space that it will be installed. Otherwise you could see additional shrinkage of up to 2mm. Timber will absorb moisture as well so always acclimatise it.
Natural timber is a lot of nuances. It is a natural product and was growing just a short time before you received it. There are many factors to consider when using timber that can differ from tree to tree. So if you are unsure about what to use and how to use it, call us. We will be able to ensure you get what you expect.