Covering crawlspace vents (in an attractive way...)

Fabrik8

Fabrik8

Overcomplicator
Joined
May 27, 2015
Location
Huntersville
So we're getting our crawlspace encapsulated and a perimeter drain and sump installed. Why any of this hasn't be done since 1989 when the house was built, I'm not sure. We had the house only two years and I'm already aware that the crawlspace has been flooding when it rains a lot, but I digress....

The vents are being insulated and sealed, leaving behind the black plastic trim bezel around the brick curtain wall and also the diamond plastic screen and insect screen. The ugly bezel and screen no longer have a purpose, so I want to get rid of them.

There are vent covers out there, but they are either really ugly, or really expensive, or a combination of the two. I don't have to do this right away, because the sealing is already done and this is just a cosmetic finishing touch. I don't mind putting some time and effort into it, because we're slowly moving through the house and cosmetically upgrading most everything as we go along. The results will eventually be worth it.

Soooo.. Does anyone have good ideas for cosmetically blocking the vent cutouts in the brick crawlspace wall?

My ideas so far:
  • Cut some flush/recessed panels out of something paintable (there are lots of choices).
  • Make a mold and lay up some fiberglass pieces with a nice looking step flange (pretty easy, I used to do lots of composites work), then paint.
  • Get a bead roller and make some metal panels with a step flange, then paint.
  • Make an inlay panel out of brick veneer. Probably bond the veneer to a backer panel and then mortar, and seal to wall with a movement control joint using urethane or whatever. That's my favorite so far, if the brick color can be matched fairly closely.
  • Patch the openings with concrete/mortar, then apply stone veneer over entire crawlspace wall. Design new garage skirtwall to match stone veneer.
I could actually do a mixture, as the vents on the front/side that are very visible don't have to be the same as the ones out of view under the decks or behind the house.

Any other ideas? Builders, architects, people with obsessive aesthetic tastes?
 
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We bricked up the ones at the old house.

We just closed the vent part of the ones at the new house. We should probably do something more permanent (especially considering some of the vent trims like to fall off), but seeing as how the house is all brick, doing something "else" would just draw more attention to the vents.

If it's all masonry, you don't need a soft joint where the infill brick meets the adjacent masonry. You can caulk it with a silicone and backer rod, but you can just as easily mortar it in.

If you're getting water in the crawl space, make sure you're getting the downspouts away from the building. I'm almost finished burying 4" solid PVC drains to daylight from all of the downspouts on the uphill side of the house.
 
shawn said:
We bricked up the ones at the old house.
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I thought they were installing covers, but they aren't. They're just insulating and sealing from the inside, leaving the damper boxes in place but removing the back panels or cutting them flush I think. I won't have full brick depth, which is the problem, so that's where veneer may work.

I may have to talk to them about this, because they aren't doing the crawlspace liner for a few more weeks. May still be time to remove the boxes completely if that is the best solution, depending on what they actually do to seal things up. That would allow full depth bricks at least...

Cosmetically, how did it look?
 
Hmm. If the edge of the metal box is recessed an inch or so, and is fairly light gauge metal, and I can remove the louvers to gain depth, I should be able to leave the boxes in place and brick them up..?

Interesting. Google says I might want to look at "thin brick".

I don't like houses. They're not enough like cars.
 
In my years of doing encapsulations, we tried everything. On the older grate style we would take and cut an 8x16 weatherproof sheet of 1/8" plastic with 1/2" foam board backing and install/seal from the crawlspace side. It gives it the illusion that nothing is there. Aside from bricking it in, that's about the nearest looking way to go about it.
 
Fabrik8 said:
Hmm. If the edge of the metal box is recessed an inch or so, and is fairly light gauge metal, and I can remove the louvers to gain depth, I should be able to leave the boxes in place and brick them up..?

Interesting. Google says I might want to look at "thin brick".

I don't like houses. They're not enough like cars.
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Is your foundation wall single row brick with block piers?

If so you have enough depth. Get the vent out and simply brick up the opening. On the inside of the brick the mortar typically spills through 1/2" or so.

When they attach insulation board to the wall, there will be a small gap between brick and insulation.

If they spray foam, you definitely want the holes bricked over so they can spray foam the whole wall.

Not sure what foundation style you have, or what insulation type they plan to use.

The important part is that the walls are air sealed, and an inspection gap remains at the top of the wall, just below the wood sill.

Before 2007, the code prevented any new construction of houses with closed or conditioned crawlspaces.

We have been doing closed crawl spaces in eastern nc since 1999.

They should insulate the wall, leave an inspection gap, and also insulate the band area, above the sill and below the sub floor.

Not to debate, but what ROI do you expect from insulating the crawlspace walls?
 
Thin brick is not intended to do what you're trying to do. Thin brick gets incorporated into precast concrete panels to give appearance of a brick veneer without the associated labor. It's only ~3/4"-1" thick, and too brittle to stand on its own. By the time you set it in a precast panel, it would be thicker than a single wythe of brick, anyway.
 
Mac5005 said:
Is your foundation wall single row brick with block piers?

If so you have enough depth. Get the vent out and simply brick up the opening. On the inside of the brick the mortar typically spills through 1/2" or so.

When they attach insulation board to the wall, there will be a small gap between brick and insulation.

If they spray foam, you definitely want the holes bricked over so they can spray foam the whole wall.

Not sure what foundation style you have, or what insulation type they plan to use.

The important part is that the walls are air sealed, and an inspection gap remains at the top of the wall, just below the wood sill.

Before 2007, the code prevented any new construction of houses with closed or conditioned crawlspaces.

We have been doing closed crawl spaces in eastern nc since 1999.

They should insulate the wall, leave an inspection gap, and also insulate the band area, above the sill and below the sub floor.

Not to debate, but what ROI do you expect from insulating the crawlspace walls?
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I just went and talked to the crew, so we're good to go for bricking them up without having to do any rework.. The vent boxes come out easily, and they're bringing back black covers for the ones under the decks. The rest we'll brick. They didn't bring the covers today so we've got time to decide which ones we want to do, so they'll do the foamboard and sprayfoam the next visit when they do the crawlspace liner.

They're doing an inspection gap, yes. They're not insulating the walls, and not actually insulating the vent openings other than using foilbacked foam board because it has it's own structural integrity. We're keeping the joist insulation because it looks like it's in good shape, and was recommended to keep it to reduce costs overall.

Should I be really scared about matching the brick for color, etc.? I've heard that's pretty difficult sometimes...
 
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Our foundation was painted, so the brick infill disappeared, not to mention foundation plantings hid most of them. We did it ourselves and it's totally easy, YouTube and patience are your friends.

If you are trying to match unpainted brick, your best bet is to call a rep. Oldcastle/Adams probably has someone local to you, but if nothing else you could send a photo to my buddy David McQueen (and tell him I said hello).

David.mcqueen@oldcastleapg.com
 
You ARE installing mechanical ventilation then, correct?

crawlspace.jpg
 
shawn said:
I don't see where it's a good idea for the crawl space to be negatively pressurized.
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Absolutely not.

But at the rate required by the NCMC it's a fart fan and 10x18 intake/exhaust louver at worst case. Unless you're treating the space like a "finished area" (which it doesn't sound like he is)

I just did an apartment complex at Elon College with 6100 sq ft crawlspace, and the calculations required a 12x18 intake (250cfm) and a 250 cfm inline fart fan ducted to a 12x18 exhaust louver (miniscule air movement). We DID however use (3) Ebac EIPL CS 60 dehumidifiers linked to humidistats. Commercial, yes, but still, ventilation/humidification in a crawlspace is a must unless you LIKE mold
 
It's not that big of a deal. You're going to want a dehumidifier down there, anyway. Just buy a cheap one and pipe the condensate to the exterior. Then provide a bit of air from the HVAC system to positively pressurize the space.
 
If I wanted to cover mine, I'd probably just get creative and cover them in some way from the underneath and leave the vents looking like vents on the outside. No matching needed.

I'm not a big fan of sealing off crawlspaces. A true believer that even the earth has to breath. Even the minuscule amount of decaying wood under there or even oxidation of any metal along with moisture / condensation from the HVAC needs fresh air to correct itself. I'm sure it can be done with dehumidifier and such but seems like NOISE. I hate unnecessary noise. Plus proneness to failure. And if not done right, you'd be flirting with a mold feeding environment.

Just speaking from a perspective of someone who just finished "retirement proofing" a house as best I could. If all possible I don't want to even LOOK under my house after I turn 50.

Wishful thinking but anyways...
 
I want negatively pressurized crawlspace so that air entering the first floor through doors and windows is pulled into the crawlspace and then out of the house.

This is also so that any odors from molds going dormant, or buildup of radon or methane etc move outside and not into the house.

Also gives an easy way to check the humidity and temperature of the crawlspace without disturbing the space through an open access door, as most remote monitoring devices are completely inaccurate.
 
6BangBronk said:
If I wanted to cover mine, I'd probably just get creative and cover them in some way from the underneath and leave the vents looking like vents on the outside. No matching needed.

I'm not a big fan of sealing off crawlspaces. A true believer that even the earth has to breath. Even the minuscule amount of decaying wood under there or even oxidation of any metal along with moisture / condensation from the HVAC needs fresh air to correct itself. I'm sure it can be done with dehumidifier and such but seems like NOISE. I hate unnecessary noise. Plus proneness to failure. And if not done right, you'd be flirting with a mold feeding environment.

Just speaking from a perspective of someone who just finished "retirement proofing" a house as best I could. If all possible I don't want to even LOOK under my house after I turn 50.

Wishful thinking but anyways...
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Humid air entering the crawlspace and condensing on the duct work is the majority of crawlspace moisture problems.

More air or exterior ventilation will only make the problem worse. The wood then soaks up the available moisture, mold grows in the wood, and the wood decays.
 
6BangBronk said:
And if not done right, you'd be flirting with a mold feeding environment.
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This is dead wrong. Sealing the crawl space is about eliminating a moisture problem and reducing the ability for mold to grow.

Ventilating the crawl space in this climate means introducing warm, humid air into a cool environment. The dew point drops suddenly, the water in the air condenses out, creating a damp environment filled with organic material. Bad idea.

 
shawn said:
It's not that big of a deal. You're going to want a dehumidifier down there, anyway. Just buy a cheap one and pipe the condensate to the exterior. Then provide a bit of air from the HVAC system to positively pressurize the space.
Click to expand...

Part of the install is a 109 pint/day (max) dehumidifier. They put that in today along with the Zoeller sump, after the electrician put in a new breaker and two outlets for them. So I'm covered by NC 409.5.1 it looks like. The dehu isn't going to do much except suck moisture out of the bare clay for a few weeks until they do the liner install, which was their goal apparently so the liner would be easier to put down and position.
 
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Mac5005 said:
I want negatively pressurized crawlspace so that air entering the first floor through doors and windows is pulled into the crawlspace and then out of the house.

This is also so that any odors from molds going dormant, or buildup of radon or methane etc move outside and not into the house.

Also gives an easy way to check the humidity and temperature of the crawlspace without disturbing the space through an open access door, as most remote monitoring devices are completely inaccurate.
Click to expand...

I'm no building expert, but if you're drawing air into the crawlspace from the house, and it's getting drawn through the doors and windows, you're just pulling conditioned air out through the crawlspace with negative pressure and replacing it with exterior air. So you're just making a leaky first floor of your house by adding extra negative pressure. Good for fresh air, bad for energy. I'm sure it's fine, I just don't know if I'd choose that solution.

I guess ultimately any method of introducing conditioned air into the crawlspace is going to do that though, unless the makeup air comes partially from the crawlspace through leakage paths. Hmm. Nevermind.
 
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