Carpentry and Woodworking - Wood species for exterior use?

I want to improve the appearance of the exterior of my frony
entrance door by adding false columns (pilasters?) and a pediment.
I was thinking of a design using fluted molding with a pilfer block at the bottom (a concrete stoop). I'm currently in Columbus and stopped at a
"wood products" store that manufactures molding. This particular
shop only uses poplar in making moldings and the salesman was
honest enough to tell me that poplar would not hold up in an exterior
application.

At Lowe's or Home Depot there are about 5 different displays of
moldings, varying from clear wood to primed MDF to polyurethane.

What species of wood is appropriate for use in triming the exteriors
of homes? Seems like there might be an "encycopedia" of what
woods to use where, but I don't know where to look for same.
Can anyone share their knowledge and wisdom in this area?

Thanks,
Jim

Almost anything used outdoors will require paint or other protection from the elements in order to endure. Few woods are intrisically weather-proof: white oak, spanish cedar, IPE, teak, to name a few. Woods commonly used on the exterior of a house: douglas fir and pine, but nicely tooled woods will generally be poplar.

Hope this helps.

JTeller,

If the application is not structural, I would highly recommend cellular PVC. It cuts like wood, sands like wood, routes like wood. It has the same density as white pine. You use conventional fasteners, although stainless steel is recommended. It's almost impossible to make it split, even if you drive a 16p nail at the very edge. If you miss the nail with a hammer, no problem. It doesn't dent easily. It needs no paint or treatment for durability, but can be painted with acrylic latex.

I am retrimming the entire exterior of my house with it. I've already completed three gables, including the triangular gable vents. I am almost ready to begin the soffits, fascia, etc. So far, I'm very favorably impressed. I don't have to worry about rot ever again.

There are many brands out there. You may have to look around to find the actual profiles you are looking for. You will probably end of buying from more than one source. Try a local lumber yard before you buy...much cheaper that the L and HD places.

Good luck,

Thanks for the info. No matter what the product I will be
painting the trim most likely a white (latex or enamel).

Chris: I am reading into your reply that its ok to use
poplar on this project, as long as I am sure to protect it
with a good finish? Is that a correct assumption? The
original; sales person suggested I use a 2 part epoxy finish
on all sides. Seems logical to paint all sides (and easy too)
but I think expoxy might be a bit of overkill.

Randy: Thanks very much for relating your experience with
the PVC products. We have a PVC fence and love it. I have
seen the product at HD (or maybe Loews) but can't remember
the price range. What I do remember is there wasn't much selection
of profiles. I had not thought about looking for these products
at local lumber yards. One or both of those stores carries a
urethane product line, but its quite expensive. But if either that
or the PVC cuts down on finish time, waste, maintenance and yhe effects of a clumsy amateur carpenter, then the extra material cost may be well worth it.

Chris: Do you have opinions on using PVC or urethane moldings?

Thanks,
Jim

I have used the dimensional (cellular) PVC (AZEK brand), shingle molding, dental molding, bed molding and brick molding. As I mentions before, not all came from the same manufacturer, but I did get it all from one local supplier, with the exception of the dental molding. Believe or not HD has the exact profile available that was originally on my house in PVC. I also purchased pre-assembled gable vents from the same lumber yard. On the WEB, I've seen just about any profile you could possibly ask for.

I have no experience with urethane.

As for price, it's not cheap. However, it depends on what you compare it with. I think the dimensional stuff I've bought runs about the same per lineal foot as cedar.

On another note, if you want white, you may not have to paint at all. It doesn't need paint for durability. If you do paint it, it supposedly last for many more years than painted wood because it is dimensionally stable and doesn't absorb moisture, which is one of the leading causes of paint failure.

As for installation, I am using a 16ga. nail gun with 2.5" stainless steel nails and stainless steel finish head screws where more strength is needed. You can also glue joints with PVC glue, which basically makes the two pieces you joined one piece. It is also recommended that you use the highest quality latex caulk...no silicone. I used DynaFlex 230.

I am not familiar with the new PVC products, but they sound good.

Lots of wood is on the outside of buildings and performs well when caulked, primed, and painted. Most exterior wood is painted. Epoxy would be overkill of great proportions.

I use wood all the time. I would use it in your application. If replacement and deterioration are problems in terms of difficulty or expense, the PVC products might bear considering.

Hope this helps.