Relative Humidity, Part II

I’ve thought long and hard about the best analogy for lumber acclimation to diverse environments, and the best advice I can give is the same advice that’s been given for years, and by people much more informed than myself on the subject: Proper acclimation continues to be the key to a positive installation result.

Think of a set of brand new kitchen sponges. Each comes sealed in the packaging with equivalent moisture content. There IS some moisture in these items—we can see that over the life of the sponge and its behavior after several uses. The drying and wetting processes of normal usage expand and contract the sponge based on the equivalent moisture found in the item.

Consider the two pictures of the same sponge here. The heater is currently running, so the air inside this place is likely as dry as Death Valley (in terms of relative humidity). The heating system installed here has no humidifier, so the only source of additional moisture is a pot of simmering water that I occasionally keep on the stove.

In the first shot, we see the sponge, dried beyond its normal level of atmospheric equilibrium by the heating of the house. This isn’t a natural state, but is a product of an extreme environment. It is, however, instructive to think of the necessity of acclimation for interior jobs such as flooring and ceiling installation.

Now, in the second shot, the sponge has been saturated and wrung out. The sponge has lengthened by over a centimeter, over ten percent! (I should have photographed the thickness of the sponge as well. Or perhaps a dry and wet one back to back. Oh, well. Ansel Adams I am not. In any event, the sponge very nearly doubled in thickness after being soaked.) Now, I understand comparing sponges to lumber is a little further than comparing apples and oranges. The processes that drive the expansion and contraction of the sponge are quite similar to those that affect lumber, or any other organic building material.

It bears mention that other factors remain in play regarding the chemical composition of lumber. Thermal expansion and contraction is another force that should be considered when installing your product. Drive over a bridge of any length sometime. The expansion joints are necessary to keep the structure looking and performing more or less the same under a wide range of atmospheric conditions. On an atomic level, heat will generate greater elemental activity, making the matter expand. (Water is a funny element in this regard—Freezing this liquid actually causes an expansion of the matter at play.)

A person can get as scientific as they want when considering the affects of humidity on their installation, but the best policy remains the one that has been in play for hundreds of years: Allow ample time (we recommend a minimum of three weeks) to allow your product to adjust to its new environment. This isn’t perfect, but very few things ever are. This rule of thumb works very well for most exterior (and interior—the time may be sped a bit in this case) installations.

Deck Tiles and Hanover Accessories: A Winning Combination!

Rooftops and other decks of limited elevation can present challenging design issues. A good work-around of many difficulties is provided by deck tiles and Hanover Elevator® pedestals.

The Hanover Elevators® are the best such product on the market—that’s the reason we offer this system exclusively.

Incorporation of Hanover Elevators® and Compensators® can accommodate construction up to 24” above the working surface. EPDM shims are available to make finish leveling a snap! Use of bracing to comprise the working grid in concert with the tile-lock system creates a sturdy deck that can last a lifetime. In cases where some roof access is necessary occasionally, these deck tiles are just what the roof doctor ordered!

Setup is simple—just layout the grid (2x2 tiles or custom sizing available), and start the placement of the elevators. This link to a handy sizing chart for estimating makes the job a breeze!

The first thing one notices about the Hanover pedestals is their sturdiness. These pedestals are thick, and are built to last. Projects with other products specified should strongly consider this Hanover system as an affordable and superior alternative.

Photo courtesy of D&L Sons Renovations, LLC.

I’ve written before about design alternatives that can accomplish just about anything outside of the two-foot limitation of the Hanover product.(link to WD art) These on-site grids can do the trick as well, so depending on the severity of the roof slope, you can choose the method of tile installation that is right for your job.

More technical and specifics of all our Hanover products available at the following links:

Elevator® Flyer

Compensator® Leveling

Hi-Tab™ Ped/Flex Shims

Spacer Tab

Compensator® Detail

Elevator® Bracing

If we can help with your design, give us a ring at 816.506.4131, or contact us via the web. We’re happy to help get you on the right path to a beautiful outdoor solution this coming season!

Acclimation: The best way to protect your investment

(This is a reprint of an article posted last June. It bears repeating, as it's the primary insurance of a quality installation.) Too often in the contracting field, unnecessary and easily avoidable errors are made due to deadlines and impatience. I’ve been a culprit of this myself. Needing to have a job done by date X, corners are occasionally cut, and it almost always shows.

When a commitment is made to a high-end decking material such as Ipe, Cumaru, or Tigerwood, it’s essential to remember that with the solid durability and resilience of these species come a few concessions. The most important allowance any contractor or homeowner can make to assure the highest quality installation is proper acclimation of the building materials.

If I were contracting an exterior siding or decking job, I would certainly allow the delivered wood to be sorted, spaced, and stacked with adequate spacing to assure proper air-drying for all four surfaces of the material. Cover it, forget about it for a week or two. Catch up on some other projects. It’s so easy to get anxious for delivery of the stock and immediately start pounding through the inventory to finish the contract. Sooner than later, this oversight will show up.

It doesn’t always necessarily happen. But I wouldn’t want to assume the risk of anything but the highest-quality installation. If the homeowner/project manager is already investing several dollars per square foot for a high-end material, the project should likely be budgeted to allow for this crucial acclimation of the lumber. Especially in the instance of finish boards, risers, skirt boards, and other applications which require direct fastening and/or plugging, having as close to a fully acclimated lumber member will prevent splitting from shrinkage or swelling of the stock when it has not yet fully adapted to the local climate.

Less splitting, a truer feel of the finish presentation of the product, and a happier customer are what can be gained by simply exercising just a bit of prudence, and sometimes allowing a job a week or two allowance providing the stock, the builder, the architect, and the homeowner a proper chance at the highest-quality overall installation.