We are seeing more and more use of PVC on homes. Vinyl siding and vinyl windows have been around for years. Now PVC trim is starting to become more common on the exterior of homes than wood. We all can understand why: we want to find the most resilient, maintenance free products we can and PVC initially presents as your best shot at that. However, what seems good on the surface does not carry through as you might hope.
Let’s talk about Vinyl windows for a short moment. The situation is much the same with vinyl windows as it is with PVC trim. Vinyl windows initially sound like the answer to all of your questions. Let’s say I have this old home with century old windows that probably haven’t been touched in over 30 years. They don’t work so great, they look a little rough, and they need regular maintenance. Vinyl windows have none of those issues. Once they are installed, they look good enough, function good enough, and have zero maintenance. Problem solved. Phew.
Now we fast forward 10 years. Does the situation look so good? Not likely. The function has likely already diminished, some glass may be fogging up, and you want to change the color scheme of your house but are stuck with that awful white vinyl window.
If we continue on another 10 years, you are likely now forced to consider replacing those vinyl windows. Soon enough you will be tossing your 20 year old vinyl windows in a landfill on top of your old 100 year old windows. If you had not tossed your original windows in the trash, they would have lasted indefinitely. They need maintenance, yes, but the amount of time you can get away with neglecting maintenance on them is likely longer than the full life of the vinyl saviors you so coveted. The large majority of the windows we work on have not been cared for in 30-50 years with no detrimental effect.
Polyvinyl Chloride in any form just doesn’t bring to the table everything you had hoped it would. It also leaves an awful mess behind it. So here are just 5 reasons to avoid the temptation to use PVC on your old home.
- Most Installers don’t know how to Install it Properly. Carpenters are often the folks installing your exterior trim. Carpenters work with wood, or at least that is how it started. PVC is not wood. If you deal with PVC like you do wood there can be major problems. Wood expands in width (across the grain) and not very much in length. PVC expends in length. A lot. expansion and contraction can create major gaps in improperly installed PVC trim. These gaps often put more stress on the caulk filling them than it can handle and the seal breaks. This allows water in. Even though PVC does not rot or encourage mold growth, I can assure you that everything behind it, from the sheething to the studs and drywall most certainly do when they get wet.
- PVC gets very Hot. Why does that matter? Although PVC takes paint just fine that doesn’t mean it will look good painted, particularly a dark color. A dark paint will make the trim even hotter and expand even more. It will certainly start to cook that paint off far sooner than you had hoped and you will likely see white lines where joints between boards failed. If you read the product literature on PVC trim you will find that they advise you to not paint their product a dark color.
- PVC does not absorb moisture. Yes, this is a positive thing in many ways but it also can be harmful. First, your paint takes a good deal longer to fully cure because paint was built with the expectation to have wood absorbing some of the moisture. Full cure on PVC takes up to 30 days; full cure on wood trim is usually half that time. That is a very large window for things to go wrong. Second, any moisture that does get behind it has no way to get out. Wood trim would be able to absorb small amounts of moisture from behind and release it to the exterior with no harm done. If there was more than a small amount that is getting in the wood trim would certainly absorb that and rot can happen. But you would also be warned before the problem got out of hand. The paint would quickly begin to fail in that area and you essentially be notified that something bad is going on. PVC would do no such thing. It would continue to look pristine while rot is devouring your sheathing and framing.
- PVC doesn’t break down and is one of the least recyclable materials out there. Once it is produced it is pretty much here to stay. Let’s just pretend that the trim installed on your house stay there forever. What about the cut-offs? They will go to a landfill and stay there forever, slowly leaking harmful dioxins into the environment. What about all of the PVC sawdust? Same thing. Meanwhile, if you used wood, the cutoffs don’t have to have the same outcome. I have brought them home to throw in my wood burning stove many times. I have regularly used our wood sawdust in my compost and mulch. Our local lumber yard sends their sawdust off to local farms for animal bedding and floor covering.
- The production of PVC is extremely bad for the environment. The dioxins released during production are some of the most toxic chemicals out there. The level of harm that these chemicals can do is quite high. According to the EPA, there is no safe level of dioxin for humans or other animals. Further, they assert that the levels in humans and children is already high enough to present health problems. What about wood? Oh yeah, it spends its pre-lumber life as a tree. Producing oxygen. Sucking up CO2.
