Learn about cellular PVC, a synthetic material that looks like wood and can be cut and painted just like wood, but doesn't rot, making it perfect for exterior trim. Find out about its other benefits over wood and get tips on how to work with it.
LESLIE: Well, if you’ve ever torn out a rotted piece of trim  off the outside of your home, you know how difficult it can be to prevent just that from happening.
TOM: True. And in some ways, the rot process starts from the very moment it is installed. It’s just a matter of time before it gets so bad that you have to replace it.
But what if there was a material that looks, cuts and paints just like wood but it can never rot? Well, there is. It’s called cellular PVC. There is a wide range of manufacturers that make it and here to tell us all about that is Tom Silva , the general contractor for TV’s This Old House .
TOM SILVA: Thanks, guys. It’s nice to be here.
TOM: Now, we’ve had synthetic materials around for years but what really seems to make this stuff stand out is that you can work it just like wood, correct?
TOM SILVA: Exactly. Same tools for using the PVC  that you use when dealing with wood. It cuts easy, it planes, it sands. You can mold it, you can turn it. I’ve easily turned it on a lathe.
TOM: Oh, is that right?
TOM SILVA: Yeah. Heated it and bent and made big arches out of it. So you can do all kinds of things with it.
TOM: And most importantly, it doesn’t rot.
TOM SILVA: It doesn’t rot. It’s not organic, so it doesn’t take on moisture, it doesn’t take on an insect. They can’t eat it; they don’t like it.
TOM: Now, I’ve had an experience with insects. In fact, we had a carpenter-bee  problem at my garage and we had – the bees would attack the fascia over and over again. I’d treat them every year, I’d fill the holes. And you know what stopped them? Replacing it with cellular PVC.
TOM SILVA: Yeah.
TOM: And it was funny because they would sort of fly around it and go, "Looks like wood. Doesn’t take like wood."
TOM SILVA: Yeah. Yeah. "I can’t land on it. This stuff isn’t any good. I don’t want to eat this." Yeah, yeah.
No. But it is great stuff. I mean it’s waterproof, basically, so water can’t get into it. Insects don’t get into it. It doesn’t peel, it doesn’t chip. You can paint it; you don’t have to paint it. I don’t recommend painting it with a real dark color. I wouldn’t use black or a dark brown, because it does expand and contract just like wood. But the difference is it expands and contracts over length, not width.
TOM: Oh, interesting. So it’ll stretch.
TOM SILVA: It’ll stretch. So you want to make sure that when you put it on in the summertime, you allow for it to compress in the wintertime. So if you have a board that’s going to go from point A to point B and it’s like 18 feet long, you want to make that board 18 foot, ½-inch and force it into the opening because it will shrink down. If you cut it to fit in there just nice, in the wintertime, you’ll have a ½-inch gap on one end or the other.
TOM: Interesting. Now, where are some of the places it makes the most sense to use PVC trim?
TOM SILVA: Well, I tell you, I’m using it more and more everywhere. It is a little more money; there is no question about it. But again, the working tools are the same. But let’s say around a garage door , where the trim hits the concrete. Window sills.
TOM: Now, that’s a good point because that is a spot that rots every single time.
TOM SILVA: All the time.
LESLIE: It’s just an invitation for rot.
TOM SILVA: Yeah. All the time.
TOM: Yeah, the wood strikes the concrete, concrete is wet all the time, water gets drawn up. Rot, carpenter ants, you name it.
TOM SILVA: That’s right, that’s right. So any place like a threshold: underneath the threshold of a door and up against the house where you may have a flashing detail under a sliding-glass door where you’re into the deck.
TOM SILVA: Anywhere that water splashing off the house can run down. The list can go on and on and on.
It’s just a great – it’s a great product. You can screw it, you can glue it. If you scratch it, you can sand it, fill it, whatever you want to do. They have epoxies that basically glue it together that are very, very strong.
LESLIE: Mm-hmm. Now, we’re even seeing these synthetics in so many other places, as far as decking and railings. Do you recommend those, as well, especially if you’re in a moister climate?
TOM SILVA: Absolutely. I just renovated my house. Now, my house is 1845, 1850. And there isn’t a piece of trim on my house that is now not PVC.
TOM: Wow. That’s quite an endorsement.
TOM SILVA: I made my railings – I have a curved stairway that enters into my house. Just a small stairway. And I actually bent all the curves. All the risers, all the stringers, everything are solid PVC.
TOM: You want to spend the time repairing other people’s houses, not your own.
TOM SILVA: Well, this is something that I had to do. It was long overdue.
TOM: Tom Silva from TV’s This Old House, great advice. Thanks so much for stopping by The Money Pit.
TOM SILVA: My pleasure.
LESLIE: Alright. You can catch the current season of This Old House and Ask This Old House on PBS. For your local listings and some great step-by-step videos on home improvement projects that you can tackle, visit ThisOldHouse.com.
TOM: And This Old House and Ask This Old House are brought to you by Lumber Liquidators. Lumber Liquidators, hardwood floors for less.