In this video, architect Steve Baczek walks through some of his favorite ways to deal with the bottom of a wall assembly, which he details with a furring strip rainscreen.
We have a lot of detailed animations on ProTradecraft; many of them show how to install wooden furring strips as a rainscreen system. But one of the tricky parts of an assembly like that is keeping pests out while letting airflow in. Of course, liquid water must be able to drain out, too, or it wouldn't be much of a rainscreen. It would be more like a reservoir.
Transcript:
Hey, Steve Baczek, architect. Yeah, coming to you from Vibe Studio. Today, we're going to talk about what happens at the bottom of that 1x3 wood furring rainscreen system.
I do have a couple of photos here. There are some other things you can do down there, too, that we can certainly talk about, but these are the two that I have done and that are probably the more common solutions.
Option 1: cost-effective mesh and flashing
So, I would say this one's a pretty cost-effective solution. You can see we have our 1x3 here, and that goes all the way to the bottom of the wall. And we have our other one there.
Notice that we have our Zip System wall there, and we have tape at the bottom. We have our wood sill down there, so we're basically just flashing over the edge of that panel and sealing that bottom edge of the Zip panel up and flashing it properly so that any water that comes down this system will drain out and drip and go down into our little stone gutter system on this particular house.
But what exactly is this material? Well, what we're looking to do is—we have a 3/4-inch space here that we basically have to fill up. So we need some kind of mesh, compressible filler screen.
In this case here, this is a ridge vent product. I want to say this is a Cobra Vent, if I remember correctly. But it basically comes in a roll—I think it's like 12 inches wide, I don't know, 25 feet long or something—and you'd have to just sit there with your utility knife and cut it up into different strips.
These are probably on the order of about three inches, plus or minus. And of course, it is right in that 3/4-inch range of compression. And then we just hit it with a couple of roofing nails or cap nails.
Installing the mesh at the bottom of the wall
Remember, it just needs to be suspended in space long enough so that when we come in here and we put in our piece of lap siding, that'll push up against it and create that nice little sandwich in there.
You know, some of the other things that I have seen people do are come in and put a piece of screen, staple the screen, and let it fall. And then, after they put the furring strips, they'll take that screen and just fold it up on the face, and then they'll tack it to the face.
So basically, what you're looking at is that you have the furring strip on top of the Zip, and that screen comes down, and they'll staple it to the Zip, and then basically just fold it around so you get closure on that space with just basically an insect screen.
It's not quite as durable—I like this mesh here.
I don't know if one takes longer than the other. I think that's subject to who's putting it in. You know, this can be pretty efficient, and you can get one of the younger guys to do this. It's a pretty easy step.
Option 2: using Cor-A-Vent for rainscreen bug control
If we're looking for some alternatives, this is a product called Cor-A-Vent. And Cor-A-Vent actually comes sized appropriately. So this is 3/4 of an inch, and I want to say this is 2 1/2 inches. They have some different sizes there.
Basically, what it is—you can see this is corrugated, right? I mean, it's like corrugated cardboard. Obviously, we don't want to use cardboard here because we would have a mold farm because of the food-based nutrients in the cardboard for the mold to sustain life.
The plastic—so water can come down, and it basically goes through those corrugations and drains out. But also important to know—air can get into that system and be able to move upwards very easily. So we get the free draining, but we also need that vertical rise through that system.
And then the other thing to notice here is that you have to plan appropriately because the wood furring is coming down and sitting on top of that, right?
So you could do it in between, but this is far easier—then you don't have to cut pieces, just the end piece, instead of trying to fit it in between all of these pieces.
Anyways, that's the bottom of a rainscreen system—couple techniques that we use to vent it. Hopefully, you enjoyed that.
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