♪ Kevin: On "Ask This Old House," our experts travel across the country to answer questions about your house.

♪ Today, Lee gives a driveway a coastal makeover... Lee: Look at that.

Nice.

Kevin: ...then we challenge our crew with a game of "What Is It?"

Jenn: Okay, boys.

It has spiral wires at the bottom.

And it spins.

Kevin: And are you concerned with radon levels in your home?

Ross helps a homeowner test and mitigate the problem.

Coming up next on "Ask This Old House."

Lee: Today I'm on my way to replace a gravel driveway with a seashell driveway.

This house is located on the coast of Massachusetts.

This homeowner is looking for that classic cape look, and the seashell driveway is a big part of it.

I love them.

I think they're really nautical and really beautiful to look at.

When you line them with cobblestones or some type of edging on them, they look really sharp.

Seashell driveways are very popular in coastal communities because of the product, you know?

You have the fishing industry, and so they're recycling the shells.

It's going to be a great transformation.

I'm excited to do this project.

It's going to look really nice.

Patrick: Hey, Lee.

Lee: Hi, Patrick.

How are you?

Patrick: Great.

Great.

Good to meet you.

Lee: Thank you.

Nice meeting you, too.

So I got an e-mail from you.

Something about a driveway.

Patrick: Yeah, yeah.

Living in Coastal Massachusetts, I see a lot of seashell driveways.

Lee: Okay.

Patrick: I love the look.

I would love to have one.

Lee: Alright.

Seashells, great.

I love them.

I have one.

They're beautiful to look at.

When you pull in the driveway, it's nice.

Patrick: Any drawbacks?

Lee: Drawbacks?

Shoveling snow.

Maybe a little rough on the feet.

Patrick: Mm-hmm.

That's alright.

I already have the gravel driveway.

Lee: So we're good.

Patrick: Yeah.

Lee: Alright.

So let's talk about the layout.

What are you thinking?

Patrick: So I was wondering if we could square this corner off.

Lee: Okay.

Are you gonna be okay going all the way back into the flower bed?

Patrick: No, I think that would get too close to the flower bed.

Lee: I agree.

Okay.

Patrick: I was actually wondering if we could shorten it a little bit.

Lee: Okay.

Patrick: 'Cause I don't need all this length.

Lee: Alright.

Perfect.

How about if we go right back to here to the septic tank?

Patrick: That's perfect.

Lee: It would be a nice, straight line.

And then coming into this area here, we might have to be eliminating that one step.

You okay with that?

Patrick: Oh, that's fine.

Lee: Okay.

Great.

Alright.

So, from there, all the way back over to this area.

What are you thinking over here?

Patrick: I was actually wondering if we could widen it a little bit.

Lee: Okay.

Patrick: I have two cars.

Lee: Sure.

Patrick: They fit as is, but just barely.

Lee: Okay.

Let's not encroach too much on the slope.

Because you got a slope.

Let's do about -- I don't know.

What do you think?

How about another 3 feet?

Patrick: Three feet is perfect.

Three feet is perfect.

How much material do we need?

Lee: So I like to do, um, length times width times depth.

Patrick: Okay.

Lee: But in a new setting, they recommend 3 inches of depth of the shells.

So we're gonna do some measurements.

Patrick: Should I help you measure?

Lee: Sure.

Let's go from the bottom, right where you're standing pretty much.

So we're roughly 30 feet.

And let's go wide.

So 30' by 20'.

Alright.

So I'm gonna call the supply company and give them the measurements that we have.

So we're 30' by 20' by 3 inches deep.

Patrick: Awesome.

♪ Lee: Okay, Patrick.

So now we got to gather up all the stone.

What do you think about the stone?

You want me to haul it out of here or do you want to keep it?

What do you think?

Patrick: There's actually a few projects I could use it for.

Lee: Good idea.

Okay.

So we'll repurpose it.

Patrick: It looks like a lot of work.

Lee: Yeah.

Patrick: How are we doing this?

Lee: Well, the old-fashioned way, we could rake it all up in small piles.

But I have this tool over here you can rent, and it's a power broom.

Patrick: This thing right here?

It looks amazing.

Lee: It's similar to, like, a weed whacker, similar style, but it has a broom on it, and this will help us gather up all the stones.

Patrick: Okay.

Lee: Make sure with power tools we always have ear protection.

Okay?

And we have our safety glasses?

Perfect.

Patrick: Right here.

Lee: I'll show you how to start it up.

Turn it on.

[ Engine starts ] Patrick: I got this one.

Oh.

Okay.

I'll follow your lead.

Lee: Follow me, okay?

♪ ♪ We got some piles.

Now we got to put them in the wheelbarrow.

Do the best you can.

Take your time.

Patrick: How deep do you want to go?

Lee: I don't want to go too deep where we're getting into the sand level.

Want to stay in the hard level.

Patrick: One layer of stone.

Lee: Correct.

The hard pack.

Look there.

That's perfect.

We're in good shape.

We left the base.

And the lines are drawn out.

And that's where we're going to expand the driveway.

And to do that, let's take out these stone edgings.

So we got this grub axe.

Okay?

It's got a pick on one end.

So I'm going to go behind it and pop it up.

Patrick: Okay.

Lee: See that?

They come right up.

Coming out pretty good.

Patrick: Yeah.

Next job, we gotta do a sod cut.

I brought a sod-cutter machine that will slice underneath the grass and take that out nice.

Okay, Patrick.

We're going to remove the soil.

So this is a Portuguese grub hoe we're going to use.

And just pull it up like that.

Patrick: Okay.

Just start here and move along the line?

Lee: Yes.

That'd be great.

We're not going down too deep.

Just on the surface.

You know what I mean?

Don't be afraid of it.

Pull it back.

There you go.

Patrick: There we go.

Okay.

I see.

Lee: Okay.

Nice.

Patrick: You make it look a lot easier.

Lee: [ Laughs ] 30 years in the business.

Patrick: There you go.

Lee: Perfect.

You want the old man to finish up?

Patrick: Unless I'm messing it up.

Lee: No.

You're doing a good job.

The old man can finish it up, though.

You know what I mean?

[ Laughter ] Patrick: It's too bad you don't have some machine that does this.

Lee: I know, right?

I think we're in good shape with the edging, but I know the shells are on the way, so let's hold off.

Patrick: Okay.

Lee: Look at that.

Nice.

♪ Okay.

We got our shells delivered.

What do you think?

Patrick: Beautiful.

Smells like the ocean.

Lee: But that's gonna go away in a couple days.

Patrick: Okay.

Lee: Alright?

It looks like a local guy down here delivered it, so that's nice.

Patrick: Yeah.

Lee: But you got a good variety.

We got some clams.

This is a quahog it looks like.

This looks like a scallop.

What do you got over there?

Patrick: A clam?

Lee: That looks like a clam, yeah.

So, over time, this is gonna bleach out in the sun.

Patrick: Beautiful.

Lee: Alright.

So let's get back to putting some edging down, huh?

So now we're going to put the plumb line down.

♪ And I'm also going to want to use the 3/4-inch stone that came out of the driveway earlier.

We'll put that down, then we'll tamp it down by hand.

Let's get a few in, see what it looks like.

That's a good fit.

Patrick: Is that it?

Lee: Yep.

Perfect.

Get in there.

We'll give it a little tap.

Patrick: Last one.

Lee: We had enough, too.

Patrick: Ooh.

A fit.

Look at that.

Lee: Nice fit.

Looks pretty good.

Patrick: Oh, yes.

Beautiful.

Lee: Okay, now we got to spread some, uh, seashells.

So all we want to do is just cast it out.

♪ Patrick: Am I going too much with the spread here?

Lee: Nope.

That's pretty good.

Just get a good even coverage.

♪ Okay, Patrick.

What do you think?

Patrick: I think it looks great, Lee.

Lee: We can see the light at the end of the tunnel.

So now last step we got to do is we got to compact it.

Patrick: Okay.

Lee: Give you the blower.

Do me a favor.

Just clean up a little bit of the edges.

What do you think?

Patrick: I think it looks great.

Lee: Not bad.

Patrick: Thank you very much.

Lee: Good day's work.

So, homework -- I need you to backfill it with some loom all the way around the block.

Patrick: Okay.

Lee: Just a little bit of loom on the backside.

And just get a little pile of this stuff.

Maybe a yard or something like that.

Just for touch-up.

You know what I mean?

Patrick: Okay.

Just to fill in where I need?

Lee: Wherever you think you need it.

Good luck with it.

Patrick: Thank you very much.

Lee: Take care.

Nice to meet you.

Patrick: You too.

Thank you.

♪ [ Saw buzzing ] [ Hammering ] [ Saw scratching ] Okay, boys.

It's shaped like a broom.

Kevin: What?

Jenn: Has spiral wires at the bottom.

And it spins.

What is it?

Richard: I know that one.

Kevin: Somebody's never used a broom.

Richard: Tommy, you and I were just talking about this.

I know we're starting to shop for nursing homes.

I know you've been looking.

Kevin: Starting to?

Richard: Yeah.

And the one I was at the other day, it was unbelievable.

You know, they got bingo at 3:00, Jeopardy!

at 5:00, and you want to come down -- Sometimes you can't make the 3:00 bingo.

Alright.

Well, it is...portable bingo.

Tom: Are there any numbers on those things?

Jenn: [ Laughs ] Tom: It's not what it is.

Kevin: Oh, my gosh.

Richard: My hand's stuck!

Jenn: Very creative.

Tom: Not even close.

This is massager.

A back massager.

Turn around, sonny.

Jenn: Oh, my goodness.

Kevin: No, no, no.

Richard: Come on!

We're all on the team.

Tom: You're gonna love this.

Look at that.

How's that feel, huh?

Let's get the back of your neck like that.

Kevin: Oh, watch the quaff.

A little lower.

Tom: Come around this way.

The handle's not long enough for that.

Jenn: Okay, okay!

Tom: Long way around.

Alright.

Wake up.

Wake up.

Wake up.

Kevin: Did you stop?

Oh.

Tom: That's it.

That's exactly what it is.

Kevin: Very nice... but not what it is.

I don't know what you all do to walk your hamster... [ Laughter ] But this... Jenn: What do you do?

Kevin: ...is my hamster walker.

Harry, my hamster, used to be on the wheel, just look at the same thing all day long.

Tom: That's what they do.

Kevin: And that seemed a little cruel.

So now I put him in and I take him out, and we walk.

And I send him forward and backwards while I walk.

Richard: He's lot a lot of weight, too.

Jenn: Very good exercise.

Kevin: The whole neighborhood.

Sprint.

[ Laughter ] Richard: Those little legs!

Those little legs!

Jenn: Okay, okay.

You're the closest because you had it touching the ground.

Tom: Oh, that's it?

Jenn: What it actually does is it picks up nuts.

Kevin: Hamster nuts?

Jenn: It could be hamster nuts, the shrapnel, but... Acorns.

Tom: Acorns.

Okay.

Jenn: All you do is wheel it right over.

Tom: Look at that!

Jenn: It's fun for all ages.

Young and old.

Richard: Any kind of nuts?

Like, macadamia?

Jenn: You can even do it from your wheelchair.

Tom: How about chestnuts?

Jenn: Chestnuts.

Tom: Look at that.

Jenn: And then you have your collection.

And there you go.

Kevin: Let me just see right here.

E7.

Richard: Oh!

Bingo!

[ Laughter ] I'm headed to a home that has elevated radon levels.

Radon is a naturally occurring radioactive gas formed from a byproduct of uranium, which is found in rocks and soil beneath our feet.

That radon gas can rise up and enter through the slab, foundation wall, through a water pipe, or a sump-pump basin.

And if the concentration rises too high, it can become problematic because it's the number-one cause of lung cancer for nonsmokers.

Now, the only way to test is actually to monitor.

You can't detect it with your nose.

It's invisible.

It's odorless.

And in this case, the homeowner installed a monitoring system, so we know that they have an elevated radon level.

So we've got to install an active system to solve their radon problems.

I'm headed to the homeowner's house right now to take a look.

♪ You must be Vincent.

Vincent: I am.

Ross?

Ross: Yeah.

Nice to meet you.

Vincent: Nice to meet you.

Ross: So you wrote in about elevated radon levels.

So tell me the backstory on how you came to that.

Vincent: I did.

So, I just recently inherited the house from my grandparents, and I would say about five years ago, uh, their dog died of lung cancer.

Ross: Oh, wow.

Vincent: And I learned that's pretty rare, especially since the dog wasn't among smokers.

Ross: Mhm.

Vincent: So I did a little research, found out about radon, and found out that radon does cause lung cancer.

Ross: Yeah, radon is actually the number-one cause of lung cancer for nonsmokers.

And then pets are at a higher risk because of the fast respiratory rate.

They're indoors, you know, for long periods of time.

And radon gas likes to settle in the basement, where a lot of times pets spend a long period of time, as well.

Vincent: Yeah, so now I'm kind of worried about myself, but also my new dog, Daisy, who's running around here somewhere.

So I did a little bit of research, and I've noticed that the neighbors over there have their own radon mitigation system.

Vincent: I can see that.

The white pipe coming up the side.

Vincent: If they have it, I mean, we definitely have an issue.

And so I bought a radon test and noticed like very high levels of radon.

Ross: You do?

So you already have a radon monitor?

Vincent: I do.

Ross: Okay.

So can we take a look at that?

Vincent: Yeah, sure.

It's right inside.

Ross: Awesome.

Vincent: Alright, Ross, I got the radon monitor right here.

Ross: Well, you're already one step ahead.

What we usually like to do is test with a continuous monitor like that to just see what the radon levels are over time.

So, how long has that been installed?

Vincent: This has been here for about three months, and I have some of the data right here.

So, this is, like, my three-month average.

And we're looking at, like, a 12.7.

Ross: That's picocuries per liter.

And the EPA recommends an action level of 4.

So you're about three times the EPA limit on the average right now.

Vincent: Wow.

Ross: The other thing to point out here is that if you look at the one-day average, you can see over the course of this last day, it literally fluctuated from 3 to 15.

So, a lot of people think that radon levels are static.

Like, you do a short-term test, and that's it.

But this is why we stress continuous monitoring, is that it's very dynamic, it's always changing.

You add cold weather outside.

You add in, you know, exhaust fans like ventilation systems, bath exhaust, dryer venting.

You add in high groundwater, like, with a lot of rain.

You add wind.

You add those things.

It's gonna change, right?

It's gonna create more chances for radon gas to get pulled into the basement.

Vincent: Okay.

Ross: So, with this, we recommend action for sure.

Vincent: And what goes into that?

Ross: So that would be a radon mitigation system.

And we call that an active sub-slab depressurization system.

That's a fancy way of saying we're gonna take a white PVC pipe, we're gonna drill a hole in the slab, stick a pipe down through it.

We're then gonna bring that pipe up, bring it out through the side of the building, through the rim joist, and bring it up the side of the building.

We're gonna put a fan on it so that it's active, meaning it's operational.

And that's gonna create a suction underneath the slab.

So we're giving an escape path for that radon to basically get pulled from below the slab and run it out through the roof.

Vincent: Okay.

Ross: Never having a chance for it to actually enter the basement.

Vincent: Okay.

Ross: This can be really easy to do or it can be really complicated to do depending on the age of the house.

I assume the house is pretty old, but how old is it?

Vincent: Yeah.

It's about 100 years old.

Ross: Okay, so, with an older house like this, we probably have compacted dirt and soil underneath our slab.

In a new house, we'd have a nice gravel base.

So when we put that fan down in a new home, it's usually pretty easy to create that suction throughout the entire concrete slab because you have a gravel base that allows all that radon gas to move.

Vincent: Okay.

Ross: In an older house, it might be a little bit more complicated because of the compacted earth.

We don't have that kind of passageway.

You know, we call that pressure-field extension.

We don't have enough airflow underneath the slab.

So we're gonna do some tests to verify that.

Vincent: Okay.

Ross: Other thing is well water.

Are you on a well or domestic-water well from a town?

Vincent: There's no well water.

Ross: No well.

Okay.

Great.

That would be the other thing that's completely separate.

But radon gas can enter through the well water on a well system, but you don't have that issue, so we don't have to worry about that.

Next thing is we're gonna call a certified radon-mitigation company to come help us out.

I already did that.

And so Chris should be here.

I'm gonna go meet him outside, and we'll get started.

Vincent: Thank you, Ross.

Ross: Alright.

Cool.

Thanks.

Alright.

Vincent, meet Chris.

Chris, Vincent.

Chris: Hey.

Nice to meet you.

Ross: He's gonna help us with the radon-mitigation system.

And so we'll start with a visual inspection.

Vincent: Okay.

Chris: Alright.

Sounds good.

Ross: So what we're ultimately doing here is looking for any openings in the slab.

Chris: So I'm gonna have to put some mortar right here.

It looks like there's another opening over here.

Ross: So what we're trying to do is because we want to seal that up so that, when we create that suction beneath the slab, we're pulling the radon gas beneath the slab and not from the basement space.

Vincent: Okay.

Chris: Looks like there's a clean-out over here that I'll have to seal, put a cover and seal with some caulking.

Ross: Yeah, so we'll seal up that corner clean-out.

Still give you access if you need to access it, but at least it's gonna be sealed up so that radon can't come up through that opening there.

Vincent: Okay.

The other thing we're gonna to do is grab samplers.

So what those are, in the four corners, Chris is gonna set up a very accurate radon monitor, and we're gonna leave the house for 30 minutes, and we're gonna watch the radon levels in the four corners to see how the radon moves through the basement.

Is it more in this corner Is it more in that corner?

Is it more in that corner?

Where is it?

Is it equally dispersed?

We're trying to figure out how that radon flows through the basement.

Vincent: Okay, and that's how you determine which access point to put the mitigation system in.

Ross: That's exactly right.

Yeah.

The hottest spot, I mean, the part that has the highest radon level, is ideally where we create that suction point and drill that hole through the slab, yep.

So we've got the results of the grab samples.

So let me show you that.

So we were at between 5 and 7 in all of the other three corners, but this corner was almost 22.

Vincent: Wow.

Ross: So this was definitely the hottest radon level.

So this would be the best place to create that suction point to basically pull that radon gas and let it get out of the building.

Vincent: Okay.

Ross: So, Chris, what do you think for location wise?

Chris: Yeah, I think a good place to go out would be up in between these two joists.

So if we could move this, we might be able to drill a hole right here, if that's okay.

Vincent: Yeah, absolutely.

Let's get that out of the way.

Ross: Okay.

So we'll do a hole here.

And we're also gonna drill three other holes at the other three corners.

So when we hook up a Shop-Vac, we can actually measure the pressure between this hole and the other three corners of the basement so we can understand how much airflow we have underneath the slab.

Okay, so we've got the four 1-inch holes in the four different areas of the basement.

We've got Chris with the Shop-Vac over there at the main suction point.

And what we're looking for is airflow pathways from the holes that we've drilled back to the main hole, okay?

So the first thing I do is for visual representation is smoke.

So this is theatrical fog.

And so without the fan running, we can just see that nothing's really going down the hole.

But now, Chris, if you can turn on that Shop-Vac... [ Whirring ] He's pulling a negative pressure.

Watch this.

See it?

Vincent: Wow.

Ross: We're good.

Chris: Yep.

Ross: So we're proving that we have an air pathway from this hole back to that hole when he creates that suction.

Vincent: Okay.

Ross: So that's visual.

And now we can also do it with pressure, right?

So this is the one that we see the most.

This is called a manometer.

What it is is a pressure gauge that measures the differential of pressure between this tube and this opening right here.

So we're measuring the pressure below the slab with reference to this basement space.

Vincent: Okay.

Ross: So we can see that we're at a very, very low level, alright?

Now if we turn the Shop-Vac on.

Chris, if you can turn that on for us.

[ Whirring ] Now watch it go up to 0.02.

Right?

0.18 -- So we have that negative pressure now, again proving that we have an air path underneath.

Vincent: Okay.

Ross: Alright?

So if we put a fan there, we're gonna create a suction here.

We're gonna get that radon gas out.

Vincent: Great.

Ross: Awesome.

Okay.

So that's great for this hole.

Next up, we do the same test at the other two holes, make sure we have an air pathway back to the fan, and then we can let Chris get to work.

Vincent: Okay.

Great.

Chris: Sounds good.

♪ Ross: Now that Chris has made a 4.5-inch hole opening, we can remove the material underneath that opening to make sure that we have a proper reservoir or sump to allow that radon gas to collect to be pulled up to the suction point.

Now we'll use a host of different fittings to allow that 4-inch PVC pipe to transition to 3-inch to then run up the wall and out through the rim joist.

♪ ♪ With that made, we can have a fan on the exterior of the building and have Heath, the electrician, wire up that fan, and we're in business.

♪ Alright, Heath.

Perfect timing!

Heath: How are you, Ross?

Ross: We ran the radon fan.

The mitigation system is in.

We are ready for power.

Heath: Yeah, I get the easy part.

Just a little bit power over here, and we'll be good.

So, looking at the basement, it looks like it's pretty simple to get to.

All we have to do is install this weatherproof disconnect outside.

It's our service switch, so it's just simply this on-and-off.

And all that's involved in this is really the plastic housing.

We're gonna have a piece of conduit go up.

It's a standard switch.

Ross: Yep.

Heath: But you can see inside, when you put that on, it just simply toggles it on and off.

Ross: Nice.

Heath: And with the cover, we have the option to lock it on or off, as well.

So we'll keep this thing running.

Ross: Yeah.

So keep it on all the time.

But if you need to service it, it's nice to kill it.

Heath: That's it.

Ross: Alright.

Cool.

I'm gonna go see Chris back inside.

♪ ♪ ♪ Alright, Vincent, the radon-mitigation system is in.

It's operational.

The fan is moving air.

Vincent: Great.

Chris: So, just a couple of things.

This is a manometer.

And as long as the fluid is higher here than it is here and doesn't look like it's even, like that, then that means the fan is working.

Vincent: Okay.

Chris: So if the fan ever stops, that will even out at zero.

Ross: That's a good visual indicator just to make sure it's working.

Vincent: Yeah.

Chris: Yep.

Also, this alarm will go off.

Once a minute, it'll beep to let you know the fan's not working.

Vincent: Okay.

Chris: All our information is on here, so if that ever stops, just feel free to give us a call.

Vincent: I will.

So how long does the fan last for?

Chris: On average, the fan will last for about 10 years.

There's a 5-year warranty on the fan.

Vincent: Oh.

Okay.

Chris: So if it ever dies, then just give us a call, and we'll come out and swap it out.

Vincent: Okay.

Great.

Chris: So, also, over here, we have a continuous radon monitor.

So we're gonna leave that for a few days, let that run to make sure that the levels stay below 4.

Vincent: Okay.

Chris: It's important to test every couple of years after to make sure the system is still working.

Ross: What's great about that, you already have a continuous monitor, so you can just leave that in place, and then, that way, you always have continuous monitoring every minute forever.

Vincent: Okay.

Ross: Yep.

Chris: So is there any other questions?

Vincent: No.

Thank you guys so much.

I really appreciate it.

Daisy and I thank you.

Ross: Awesome.

Awesome.

Vincent: Thank you, Chris.

Chris: Thank you.

Alright.

Take care.

Vincent: You too.

Ross: We'll see ya.

♪ Kevin: Next time, does your furniture have water stains?

Tommy gives a few tips on ways to remove them.

Tom: Look at that, huh?

Kevin: Then Jenn discusses the importance of soil selection when choosing houseplants.

And Mark helps a homeowner repoint their brick floor.

Mark: You can see water got in and eroded it, right?

You know, it's very soft.

And then there's holes.

Kevin: All that on "Ask This Old House."