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Posts Tagged ‘wood pergola kits’

Should I Use Polyurethane on My Pergola or Arbor?

Saturday, August 28th, 2010

Question: I just bought a brand new pergola kit from, and now I’m looking to add a finish to the wood.  I’m used to working with indoor furniture and woodworking and use polyurethane on most every project that I work on.  I’m wondering if polyurethan works for an outdoor project as well?

Answer: That depends.  First and foremost, there are two different types of polyurethane, one made for indoor materials and another that is specifically formulated for an outdoor application.  The outdoor version has special additives that make it suitable for withstanding the rigors of outdoor life, especially UV rays.  The second aspect of this decision is regarding the wood.  If your pergola or arbor is made from an oily wood like Shorea or Teak, then polyurethane won’t work.  A poly finish on one of these woods will act like a sealant on the wood, and then the oils will need to come to the surface at which point the poly cover will bubble and peal.  It will then be very difficult to remove.  So, if you bought a pergola kit made from Cedar or Redwood, you’ll be OK.

Which wood should I use for my pergola or arbor?

Tuesday, August 17th, 2010

There are not too many domestic woods that are suitable for an outdoor project like this.  Here’s a list of domestic woods that you’ll be able to find for your pergola or arbor.

  • Southern Yellow Pine - It’s cheap and readily available, but you’ll have to treat it for it to last more than a couple of seasons.  It also is bug food and has sap when not treated.  $3 per linear foot.
  • Douglas Fir - This strong, northwestern softwood is stable and sap-free in clear, vertical-grain cuts. Less rot resistant than red cedar and redwood.  $29 per linear foot.
  • Redwood - Premium western softwood that’s stable and sap-free. Clear grades like this are costly.  About $37.50 per linear foot
  • Eastern White Cedar - It grows on the eastern half of the US.  It’s a stable and sap-free with small, tight knots. $27.50 per linear foot.
  • Cypress - This is a tropical wood that grows in the US, and there aren’t many, it has a tan color and is related to redwood.  It is stable and sap-free. Can have small, tight knots.  $17.50 per linear foot.  This is a great wood, that has a middle range price.
  • Western Red Cedar - A Pacific Northwest wood with superior rot and insect resistance. Stable and sap-free. $6.50 per linear foot.  This is a favorite of ours because of it’s value.  Dollar for dollar, you won’t find a better wood for performance and looks.

Cedar vs. Treated Lumber

Wednesday, June 2nd, 2010

Picking the right wood for your garden structure will determine many things about it. The wood choice will determine its overall look, color, longevity, and in many ways its design. Cedar and pressure treated pine are by far, the most commonly used woods for outdoor projects like a pergola, arbor or trellis. So, this article will outline a few point that are involved in that decision to help you end up with the wood that fits your backyard or garden.

The vast majority of pressure treated wood at your local hardware store will be yellow pine.  It is typically a yellowish color, that can look a little green when treated.  The main benefit of using pressure treated yellow pine is its cost. This route will give you the cheapest pergola possible without stealing it. So, if the price is your main concern, then the decision has already been made and you will have a pine arbor. There are some other factors involved in the choice for most people, though. One being environmental, because most treated wood is treated with a three chemicals known as CCA, chrome, copper and arsenic, with arsenic being very dangerous to your health. If you are a do it yourself kind of person, then you will end up with this stuff in your lungs after the project, and if your kids will be playing on it then they will have it on them too. And, don’t even think about growing grapes on your arbor that’s has been treated with CCA. In the treating process, these chemicals are added to the wood, often, when it still has a very high moisture content. This plays a part in the cheaper price, because you don’t have to dry it, but it also might lead to some downfalls in your garden structure. Wet wood will change in shape considerably as it dries, which can lead to bowing, warping and cracking in your pergola or arbor. Overall, treated yellow pine is satisfying many people out there that have built their decks and hardscape using this choice.

In the US, cedar is a very popular choice of wood for outdoor projects.  There are many benefits to using cedar, and a few drawbacks.  The main drawback being that it is a softwood, like pine, which alone might not be considered a drawback.  But, if your pergola design needs a wood that is very hard and dense, for example if there were any moving parts that might wear or it would be subject to scratching from a nearby or attached object, then being a softwood might pose a problem.  If you need a wood that is very heavy, then Cedar isn’t the right choice.  The benefits are many, starting with its resistance to the effects of weathering.  Cedar has a natural chemical compound in it that makes it resist weather effects, moisture, mold and insects.  It also has a pleasing odor.  Cedar has a reddish brown color, and is generally easy to sand, cut and finish.  Though, it isn’t as readily available as treated pine, you will find it in almost any lumber yard or DIY store.

Overall, cedar, in particular western red cedar, is the best choice for a backyard structure, due to it’s natural weather and insect resistance, and being readily available when compared to pressure treated wood.