Wednesday, July 8, 2009

Deck Stain Problems

We are in the middle of deck season again and we continue to receive calls from clients across the country continually dissatisfied with the deck products they have used to protect their deck or other exterior wood. We continue to fight the fight for homeowners confused by the array of products advertised and sold and the various confusing choices available.

I believe deck care is probably one of the most frustrating and disappointing aspects of home care and maintenance for many homeowners. There are many false claims with regard to frequency of maintenance and long-term performance. Most of the products heavily advertised and sold in the big warehouses and depot type stores continue to fail, yet are difficult to strip and maintain. Many of the products are chosen based on consumer publications and various so-called “test results”. We seek to share here and on our website the input we received from clients as well as a results of our continued testing of the various products available.

One of the best-known water sealers available is mostly paraffin wax and mineral spirits. The wax does a great job of beading water for a few months, then weathers away, and the wood is left unprotected the rest of the year. Once wax is applied to the wood it makes future wood care difficult and generally will compromise future results of anything applied later. Many of the new acrylics and water-based stains are proving problematic after the second or third maintenance coat leads to buildup of product, trapping of moisture, and peeling. The acrylic products however are very difficult to strip if you have a failure. Most readily available deck strippers will not break the bond of an acrylic resin product. We are highly frustrated at the amount of stripper needed to undo the disappointing results of many of the water-based deck and log care products being sold. Even the good old fashioned oil base stains are short lived, and many times lead to darkening and mildew issues in some climates.

A majority of the products currently sold lead to future stripping at some point in the maintenance process. By choosing the proper application techniques and the proper products for any particular project, we can eliminate millions of gallons of strippers and harsh chemistry being rinsed into backyard soils and streams.

The horizontal nature of a deck exposes the wood the maximum sunlight and whether exposure. Rain, snow, and ice lays on the surface for extended periods of time, the sun heats and degrades the surface , moisture is drawn into end grain and uncoated backside, grit and sand are ground into the surface, and the deck faces abrasion from furniture, dogs, and humans.

In the past, the majority of decks were built with pressure treated wood. Old-growth forests, which were a great source of quality stable wood are virtually nonexistent now. Second growth forests are younger fast-growing trees that are high in sapwood and knots. Milling procedures for smaller trees result in mostly face grain lumber which leads to various problems with staining or coating.

In some cases treated lumber is “pre-coated” and some new wood must be stripped before the proper stain can be applied. Look at the tags on wood for finishing schedule instruction.

Once a poor performing product is applied, homeowners are faced with a vicious cycle of repair and maintenance that usually ends up leading to stripping the failed product. During the first few years, the wood becomes deteriorated, and future results with any product are somewhat compromised. Clients will then try another product that may lead to equally disappointing results and the cycle continues.

Common problems with deck care and deck stains:

Historically, there are several other factors that led to the common dissatisfaction with deck care in general.

1. Decks constructed with wet wood

2. Incorrect product choice for staining or finishing.

3. Lack of a sealer or coating on the bottom side and end grain saw cuts.

4.Many confusing choices available that are heavily advertised and sold by suppliers with little experience or real-world testing. Most employees in the warehouse and national paint stores are seasonal and temporary help with little wood care experience.

The ultimate key to proper wood care and satisfactory deck maintenance should start before the deck is even constructed. We should assure that the wood is properly dried, coated on the backside, and sealed on the end grain where saw cuts are made. Once the deck is constructed, it is difficult to seal the end grain (a big source of moisture intrusion), and it is difficult to seal the underside (a cause of cupping). With these two sources of moisture intrusion, you have a deck that is prone to the boards expanding and contracting as moisture levels in the wood increase and decrease due to existing conditions. The expansion and contraction of the wood, combined with moisture exiting the wood will cause compromised results with most stains and wood coatings, and will usually lead to eventual warping, splitting, and cupping of the wood.

Seal all saw cuts when the deck is built and saw cuts are made. Open end-grain is another tremendous source of moisture intrusion. Saw cuts cannot be sealed once the deck is built. The solution to this common problem is to get your wood a few weeks before the deck is going to be built, and stack it with spacers allowing air movement through the stack . This allows the wood to dry slowly before the deck is built. Once the wood is dry, a sealer or waterproof or can be applied to the backside and all saw cuts as the deck is being built. Once construction is completed, the topside of the deck can be stained, sealed, or finished with the appropriate product.

So what do you do if your deck is already constructed? We recommend a waterproofing sealer to be applied to the bottom side of the deck either by mini roller on an extension, or a pump sprayer. Try to flood material into cracks between the boards and end grain saw cuts when coating the top of the floor. By eliminating all sources of moisture intrusion, we reduce the expansion and contraction of the wood that leads to cupping, warping, and splitting.

Selecting your stain or wood protection

There is no single best product for every deck or log home, rather there is a specific best product for each individual project based on existing conditions, client expectations, and maintenance capabilities.

Before making a choice of the wood stain or finish, a few questions need to be asked of the client:

1. Is this new or existing wood? Is it pressure treated?

2 Is the wood IPE, or Other Exotic Wood? Cedar, or Redwood?

3 Is the deck covered or in full sun?

4 Is the client willing to completely remove any existing coating? Many times when a previous sealer or stain has been applied, we must completely remove any existing failed stain to get good performance out of a new product.

New wood also presents a variety of issues to consider as to when to stain or coat, the preparation required, and the best longest lasting protection.

Ipe, Mahogany, Tiger Wood, and other exotic hardwoods always present a unique challenges to successful staining and beautifying.

One TIME on Ipe (Brazillian Walnut)

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