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

♪♪ Today, Nathan heads to Tulsa to bring some curb appeal to a street-side utility cover in need of repair.

Then Ross will educate us on the dangers of low-level carbon monoxide exposure and what we can do to protect ourselves.

Plus, what do you do when your fireplace is covered in creosote?

Give Mark a call so he can work his magic.

That's all coming up next on "Ask This Old House."

♪♪ Nathan: I recently received an e-mail from a homeowner out in Tulsa, Oklahoma, who said he's got a little bit of a curb-appeal issue he'd like help with.

He moved out there about a year ago with the Tulsa Remote program, which is a really cool idea where they're actually giving you money to move to the city and work from there.

It's actually kind of an interesting idea considering so many people can work from home now.

Looking at the forecast, it looks like we have a little bit of rain coming.

Hopefully it holds out, but I'll grab my rain jacket, my tools, and we'll head on over.

Hi, Dwayne.

Dwayne: Hi.

Welcome to Tulsa.

Nathan: Nice to meet you.

Dwayne: Nice to meet you.

Nathan: I heard you're a new resident here.

Dwayne: Yeah, I just moved here about a year ago.

Nathan: What brings you to Tulsa?

Dwayne: Well, Tulsa Remote program.

I'm from Wisconsin, so a lot of stuff to do here that I didn't have, like the Gathering Place.

Nathan: Yeah.

Dwayne: There, Turkey Mountain.

Nathan: Oh, nice.

Dwayne: Paintballing indoor.

I mean, there's...

I can go on and on, but lots of things to do, and I absolutely love it.

Nathan: You wrote me about a curb-appeal project that you wanted to spruce up.

Where is that at?

Dwayne: Right over here.

Nathan: Right.

Dwayne: So, here is the project.

Nathan: Yep.

Dwayne: As you can see, the wood's rotting, a lot of green moss buildup here.

Wood's breaking down here.

I'm not even sure if it's up to code.

And the ground is also unstable, it seems like.

Nathan: So, it's seen some better days.

We can definitely make some improvements here.

So, first off, what we're working around is this gas meter here.

And they did do it right.

They enclosed three sides, but they left the top and the rear open, which is good.

That's to code.

We definitely want to replicate that.

We don't want to make it too tight.

We want to give, you know, emergency services or any utility services the opportunity to come if they need to shut it off in an emergency or if they need to swap a meter, give them the opportunity to work on it.

This one, you know, they drove some stakes in there.

I'd rather not drive any stakes in.

I'd rather try and make like a wide base that it'll just be really heavy and just sit down.

Dwayne: Okay.

Nathan: And that way, too, if they ever had to do a larger service on it, they could move it out of the way and put it back when they're done.

I think it's going to be a pretty fun project.

Want to give it a try?

Dwayne: Sounds good.

Let's do it.

Nathan: Let's just try pulling.

Seems pretty loose.

Let's try pulling this out, too.

Oh, yeah, that's even easier.

Hey.

Dwayne: Hey.

Nathan: This is the stuff I picked up, and I decided to set up under your awesome carport because it looks like the weather might change on us.

So, we'll try and build the whole unit here and then bring it out there and set it in place.

But I just want to show you what I picked up.

To start at the bottom, I have this pressure-treated 2x6.

So, what this is going to do for us, it's going to be in ground contact, so it's very rot-resistant.

That'll make a really nice base for us to build off of.

I'm going to do cedar for all the rest.

I'm going to do my posts out of cedar 2x4s.

I have some of this cedar fencing panel that we'll use and we'll run it horizontally.

Really nice, clean look.

And then I'll cap everything off with this cedar 2x6.

Over time, you can sand it, you can stain it, you can just let it gray out.

It'll really age nicely.

I thought it'd be a nice touch to maybe pick up some house numbers.

So, I picked up your five, five, four, six in these four-inch black numbers here.

You like the look?

Dwayne: Yeah, kind of pops.

Nathan: Yeah, and I think that'll fit nicely, too, if we're going to run these horizontally.

We'll pick a nice spot at the end of it and put those on.

Glue for any of our miters.

Attaching our base and our cap, we're going to use these 3-inch screws.

And then for attaching our cedar fence panels, I'm going to use these stainless screws.

These have a nice head on them.

It's really going to hold that in, instead of using like a finish nail, which might pop out over time.

These will age really well.

They'll never rot.

So, I think we'll get started.

We'll move everything off and we'll get started by building the base.

Dwayne: Okay.

Nathan: Alright.

[ Saw whirs ] Alright.

So, now that we have a long point, I'm going to go 42 inches.

And then what we'll do is we'll use that as our long point.

So, we'll come back off of that.

And then the remainder, now we have another long point.

I'll cut another 2-foot piece and that will be all we need for the base.

Dwayne: So, my question is, what is the tint in here?

It looks like a greenish-blue tint.

Nathan: So, it's actually copper.

It's one of the major components that they infuse the wood with nowadays to keep the pests and the bugs from eating into it.

Now that we have a long point there...

...I'll just pull 2 feet off of that, and this will just be a regular 90-degree square cut.

It likes those short little square cuts.

Not those long miters.

Alright.

Alright.

So, now what we have is the three pieces we need to build up our base.

So, we've got a nice miter there.

Nice miter there.

And then what we were looking for is a minimum of 24 inches in between.

And we have 30.

So, now we're going to have plenty of room to move this back and forth.

We're not going to choke down on that gas meter at all.

So, to attach these together, I'm pretty much just going to do a few toe screws.

[ Drill whirs ] Alright.

Alright.

So, the easiest way to find the height for our posts that we're going to cut is just to lay out the material that we're going to use.

I'd rather not have to rip anything, have any custom pieces.

So, these come at 5 1/2 inches.

They're somewhat consistent.

They vary in size a little bit.

But if we just slam five of them together, we get 28 inches.

And we're looking probably... 27 inches was the old one.

A little bit higher won't be bad.

If I gap these a little bit, about an eighth, strong eighth in between each one, we may finish at about 28 1/2 inches.

I think that would be a good look for us.

So, we'll cut four posts.

Or, we're actually going to cut six because we're going to join them together.

We'll cut six pieces of that cedar 2x4 at 28 1/2 inches.

Dwayne: Okay.

Nathan: Alright, so we want to join two of these together, two of these together to make our post for the front.

And then these are going to be left single.

We'll add those to the rear.

[ Drill whirring ] Alright, so we got our base back up, we have our posts cut, and what we're going to do is think about our layout and our placement for these fencing boards as they come up.

So, we can flush it to the front like that if we want to, or we can hold it back a little bit, give it a little bit of a reveal.

Dwayne: I like it flush.

Nathan: You like it flush?

Alright, so that's easy.

It'll help us with our layout.

What we're going to do is flush that right to the front.

I'm just going to make a pencil mark.

Alright.

And then we'll do the sides.

So, what we did is we just created a setback.

So, now we know we have our post...

When we put our post in, it's going to come right into that corner and mount right there, and then we'll take our single, mount it back there.

Panels on the front.

It'll be nice and flush.

So, now we're ready to install these.

♪♪ ♪♪ We cut some of this extra 2x4.

It's actually pressure treated, but we're going to... we're going to use it anyways to stiffen up this top.

Alright, we're ready to start cutting these cedar fencing boards.

Luckily, I can get three pieces out of each 6-footer.

♪♪ So, I need five for each side and I need five for the front.

♪♪ ♪♪ ♪♪ Alright, now we're ready to finish off the top.

I grabbed a nice piece of premium 2x6 cedar, and it's going to be kind of like the bottom.

I'm just going to make it a little bit longer so we have a 1-inch overhang all the way around.

So, let's do a little glue on this miter.

♪♪ Alright.

You want to go see if it fits?

Dwayne: Yeah.

Nathan: Alright.

Alright.

Alright, lower it down.

Seems that wants to go down there.

Good.

So, the last thing that we're going to do is for a little added weight, I'm just going to drop a couple pavers in on that bottom plate.

Dwayne: Okay.

Nathan: If you feel like you need to add more over time, you can do that, but this is just a little bit of extra weight.

Alright, Dwayne, what do you think?

Dwayne: I think it looks great.

Nathan: Yeah, it came out nice.

You can let it gray out, you can paint it, you can stain it, add a little mulch or a little seed, let it blend right in.

Dwayne: Sounds good.

Thanks for coming to Tulsa.

And maybe next time we'll have some fun.

Nathan: We'll be back.

♪♪ Kevin: Hey, Ross.

Ross: Hey, Kevin.

Kevin: More detectors you got here.

What are we talking about?

Ross: Talking about carbon monoxide, especially low-level carbon monoxide.

Kevin: Oh, okay.

I was going to say, we have talked about carbon monoxide before.

Ross: Right.

Kevin: So, alright.

So, what do you mean, low-level?

Ross: Right.

Carbon monoxide comes when you burn stuff, right?

So, fossil fuels, oil, gas, propane, wood.

And when you burn things like that, carbon monoxide is one of the by-products of combustion.

Kevin: And we have combustion in our houses in a whole bunch of different places, whether it's the furnace in the basement or the gas stove or I guess even our fireplace.

Ross: That's right.

So, when those don't burn right, we introduce carbon monoxide.

And if they don't vent to the outside, they come back into the building.

Kevin: Right.

Ross: Okay.

So, the first line of defense is your UL-rated carbon monoxide alarms.

These are them right here.

You see them on the ceilings.

Kevin: Yeah.

Ross: Right?

And they are there to give you life safety.

Meaning if they beep, you need to call 911.

You need to get out, right?

Kevin: Right.

They're basically code, right?

I mean, I have to have these or should have these in my house.

Ross: They're code.

Kevin: For good reason.

Ross: Exactly right.

Yep.

And they have to be specific areas around the house.

Very, very important.

Right?

The other thing that people don't realize, though, is that they have thresholds that they have to meet to be UL-rated, okay?

So, 70 parts per million for up to four hours is where the first tier that this thing will alert you at.

Kevin: Whoa, wait, wait.

You're telling me that it's not just the amount of carbon monoxide in the building, but it's got to be there for four hours?

Ross: That's right.

Kevin: This won't go off until four hours has passed?

Ross: That's right.

At 70 parts per million.

Kevin: Aah!

Ross: Exactly.

Right.

So, it's concentration in time.

And a lot of people don't realize that.

If it goes to 150 parts per million, it will have to be there for up to 50 minutes before it alerts you.

And the same thing when it gets to 400 parts per million, it's 15 minutes, right?

So, it's there to make sure that it alerts you properly so that you don't die.

Kevin: But if this isn't going off, it doesn't necessarily mean I don't have carbon monoxide in my building?

Ross: Right.

It's crazy, right?

You could be at 20 parts per million forever and it would never, never go off.

Kevin: Well, now I have a headache.

Okay.

So, that's what these things do?

Ross: So, these are low-level carbon monoxide monitors.

So, these monitor carbon monoxide and they measure all the way down to five parts per million.

Okay, and they give you a continuous readout.

You can see it's zero right now.

Of course, if we had carbon monoxide, that level would increase and it would tell you what it is, real time.

Kevin: So, that's actually really good to know because, as you say, it will tell me if I have it and it will tell me at what levels.

Ross: At what levels.

Exactly.

Kevin: Will it alarm?

Ross: And it will alarm.

It will start off with a visual alert and then it will go to an audio alert -- it will beep.

Kevin: at what level?

Or do I set that?

Ross: So, it depends on the manufacturer.

Yeah, so some of them start at 10, 15, and up to 30.

Kevin: Yeah.

Okay.

So, why is it so bad for us?

Like, what actually is going on?

Because, you know, you guys have described carbon monoxide as odorless, tasteless.

You can't see it.

Ross: That's right.

Kevin: It's pretty insidious.

Ross: That's right.

Kevin: But what is it doing to us?

This makes us sick.

Ross: So, yeah.

So, when you have carbon monoxide in your building and you breathe it in, right, your red blood cells will go after the carbon monoxide versus the oxygen.

So you're actually replacing oxygen in your red blood cells with carbon monoxide.

Kevin: Mm.

Ross: So, you're slowly increasing the carbon monoxide of your red blood cells over time.

And then it starts off with, you know, headaches, fatigue, and then it can increase all the way to nausea and flu-like symptoms, and then eventually, obviously, you can get into death, like we talked about before.

Kevin: You're basically suffocating, essentially, from the inside out.

Ross: Exactly right.

Yep.

Kevin: Phew.

Ross: Yeah.

So, very scary.

Kevin: Alright.

So, just a little bit of pushback.

If you're telling me that there's a device on the market and it's UL-rated and it has to be in our houses per code or whatever and it's not going to alarm until we get...70 parts per million for four hours?

Ross: That's right.

Yeah.

Kevin: That suggests to me that levels below that aren't something that I should be worried about.

Otherwise, these guys would be changing their rules.

Ross: That's right.

Kevin: Why do I care if it's 20 parts per million?

Ross: Well, there are multiple studies that have been released that talk about how at risk you are at different levels.

Right, and so depending on if you're an infant, pregnant, you know, an elderly person, immunocompromised, different levels of CO are going to affect you differently, right?

Kevin: So, vulnerable populations are going to be affected.

I get it.

Ross: Absolutely.

Yeah.

And so, if you look at some of the EPA and some of the other standards that are out there, like OSHA, for example, basically has an eight-hour time average of 35.

So, if you're indoors for up to eight hours, you should never see more than 35 parts per million.

That's, of course, half.

Kevin: And so, if I'm a perfectly healthy person, is there a level that I'm comfortable with or...?

Ross: I mean, me personally, zero is where I'm trying to be.

Kevin: Well, look at you, man.

Just look at you.

You're a zero ppm kind of guy.

Ross: I'm just not happy with CO in my space, in my space, in any house, in any indoor environment, right, we don't want carbon monoxide.

There's a reason why it's called the silent killer.

Right?

And even at low-level amounts, it's still going to affect us in a negative way.

Kevin: It's persuasive when I hear that these don't tell me if it's there and those tell me if it is there.

So, how much?

And where do I put them?

Ross: Yeah, so, $100 to $200 for the price point.

And then on top of that, location.

You know, what we would recommend -- where do you spend the most amount of your time?

It's in the bedroom, right?

That's where we're most vulnerable.

So, eight hours a day in the bedroom, that's the first place.

If I could pick one location, it's going to be the bed or near the group of bedrooms in your house.

If I could take it a step further, depending on the size of the house, maybe one of the basement, maybe one on the first floor as well, depending on where you have other carbon-monoxide-generating devices, like fireplaces, furnaces, boilers, et cetera.

Kevin: Cool.

Yeah.

Listen, I thought we were done talking about carbon monoxide, but lots more to learn.

Ross: Yeah.

Kevin: Thank you.

Ross: Awesome.

Alli: Mark, hi!

Mark: Hey, Alli.

How you doing?

Alli: I'm great.

Mark: Alright.

Alli: Welcome to our home.

Mark: I love this room.

This is great.

Alli: Yeah.

We call this the big room.

Mark: Okay.

That fits.

Alli: There's a lot of.

historical details that we really love about this house.

Mark: Yeah, I noticed two fireplaces in there.

That's awesome.

Alli: You have two in there.

Now, one in the formal dining room here.

Mark: Wow.

Alli: We have a total of ten.

Mark: Ten?!

Alli: [ Laughing ] Yeah.

Mark: You're lucky.

Alli: Yeah, and like any house, we end up spending the most amount of time here in the kitchen.

Mark: Okay.

Alli: So, the fireplace we wrote you about is here.

Mark: Right.

Alli: There's a lot of cool things about it, but some cleanup that we want to do, especially with the creosote buildup, before we're really comfortable using it.

Mark: Okay.

Alright.

Couple things that I do notice.

I love that grill over there.

You can use that for cooking, which is fantastic.

I really love this cooking arm right here, so you can take your pot out, put your pot back, boil your water.

But, unfortunately, what I also noticed was all this creosote back here can be dangerous.

Alli: Yes, a lot of cleanup that we've been trying to do.

So, we burnt a couple of creosote logs.

We've taken some dish soap and scrubbing over here.

But as we're getting into more of the buildup of the creosote, a little unsure of the next steps we should be taking.

Mark: The main issue with creosote is that it is extremely flammable.

The more creosote that you have, the bigger the risk.

I think we can handle it.

It is pretty bad.

First thing I want to do, though, is grab my flashlight.

We should check everything out while we're here.

Okay.

So, just as suspected, we do see a little bit of creosote buildup in the flues.

So, creosote comes in three different stages.

What we have in these flues is stage one.

It's really just an ashy substance.

But what we have in this firebox is stage two and stage three.

Stage two is all this flaky stuff that you're looking at, which is pretty bad.

But the worst of it is what we call stage three.

And you can see the oily substance, very shiny.

That's the real danger part.

So, we definitely want to concentrate, get rid of that.

Alli: So, what exactly is creosote?

Mark: Creosote is when fossil fuels -- and in this case, the fossil fuel is going to be the wood -- when it doesn't combust the way it should.

So, if the fireplace isn't working as great as we want it to, the burn is going to be a lot slower, and that's going to create a lot of the creosote.

And one of the big culprits when you use the wood is the logs are wet or they haven't been dried out properly.

That's going to cause the creosote.

And the biggest culprit, to me, is when people burn pine.

It's very soft, very wet and sappy, and that turns into creosote very quickly.

Alli: So, how do we tackle this now?

Mark: You have to remember that this is very, very hard to remove, so we're going to do a few different things.

Alli: Great.

Let's do it.

So, where do we get started?

Mark: Alright.

So, what we're going to do first is we're going to start out dry, okay?

And what we're going to do is we're going to use this metal putty knife.

That'll take off a lot of the flakiness and a lot of the stage-three stuff, hopefully.

We're also going to use this 4-inch grinder.

It's got a metal wheel on it.

Hopefully, that's going to help us take off the leafy stuff and the hard stuff.

We're going to also use a drill with an abrasive blade.

That should take off some of the other heavy stuff.

After that, we're going to wet the wall down and we're going to use chemicals.

This guy right here, you can get out of any store.

Hopefully, that takes care of everything and that works.

If it doesn't, we're going to get more aggressive.

I took this out of the brickyard.

It's got some stronger chemicals in it.

All we're going to do with that is use this bristle brush.

We're going to take this material and kind of spread it, let it set up, and then hopefully it's doing its work, we wash it down, and some of this stuff disappears.

Importantly, we want to make sure we're safetied up.

A set of goggles and gloves for you.

Same for me.

And the last thing we want to make sure is we have proper ventilation.

So, open doors, open windows, as we have, and that should be able to get us started.

Alli: Great.

Let's do it.

Mark: Alright.

Alli: So, what's the technique with this?

Going for it?

Mark: Just going for it.

That's it.

Actually, I'm pretty happy with the start.

Alright, Alli, you want to try it out?

Alli: For sure.

Mark: Alright.

Step right in.

Alli: So, this is the three?

Mark: That's the three you're on.

There's a little bit of two there, but... Alli: Yeah.

Haven't actually felt it yet.

Mark: There you go.

Making it red, Alli.

Alli: Yeah.

Pretty satisfying.

Mark: Looks good.

Yep.

Alli: It is kind of crazy how tough the three is.

Mark: The three is, so you can really feel the difference.

Alli: Yeah.

So, is this something we should be doing every year or...?

Mark: Yeah.

If you have a heavy year of fires, you know, make it a spring project.

Alli: Got it.

Can you scrape too hard with the metal?

Mark: Pretty much no.

Alli: Got it.

Mark: Wow, that's looking good, actually.

Alright, Alli, those knives worked pretty well for us.

Right now, I think I'm going to try the wire on the grinder.

Give me a few minutes to see what I can get out of that.

I'll get out of your way, you jump in with the abrasive pad, and we'll see what we can do in this section.

Alli: Sounds great.

♪♪ ♪♪ ♪♪ Mark: Now I think all we have to do is apply the cleaner.

First thing we want to do is just dampen the wall a little bit.

It's already starting to work.

Wow.

Wow.

Wow.

♪♪ ♪♪ Alli: Wow.

What a transformation.

Mark: Alright, Alli, I'm so happy with the way it came out.

But I am going to leave you with a little bit of homework.

Don't forget, we couldn't get up on top of that damper.

So, all you have to do is call a chimney sweep.

They'll come in with some brushes.

I've already checked out the flues.

They're in perfect condition.

So, just a scrub, and you should be ready to go.

Alli: Wonderful.

For being such a focal point of our kitchen, we're just so excited to have red brick again.

So, thank you so much.

Mark: Alright.

Well, you're welcome.

And if you have questions about your house, we'd love to hear from you, so keep them coming.

Until then, I'm Mark McCullough for "Ask This Old House."

♪♪ Kevin: Next time on "Ask This Old House"... are you considering connecting a backup generator to your home?

Heath will share some options and tips for what you need to know.

Then we will answer all your questions on asbestos abatement.

Plus, Mark helps a homeowner repair a sagging brick lintel on his 1830s home.

Mark: You have a museum piece right here.

This is a piece of art and should be repaired as such.

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