Thread: Gravel in Crawl Space

Last one for today, I promise.

Idiot architect (I should not single him out, this happens all the time) specifies "6-mil polyethylene with clean gravel above" as a crawl space covering. The gravel is not specified, other than "clean". So builder boy uses crushed rock. He also decides that the rock will tear the poly, so he uses weed block cloth instead. I could go on, but I digress.

The question is this: once they install the sump pumps and ventilation fans that they "forgot to install" (just like they "forgot" to install foundation vents), they will have mechanical equipment in the crawl space which will require servicing. There will be a hospital visit immediately following each service call thanks to the crushed rock.

Give me a code bullet to kill this guy with, please!

And, did I mention? 15,000 s.f. new construction? What is this world coming to??????

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Aaron,

Other than the common sense bullet, I think you are dreamin' on a code cite for this one.

Originally Posted by A.D. Miller

Give me a code bullet to kill this guy with, please!

R106.4 Amended construction documents. Work shall be installed in accordance with the approved construction documents, and any changes made during construction that are not in compliance with the approved construction documents shall be resubmitted for approval as an amended set of construction documents.

BUT FIRST ... the architect will need to sign off on the changes.

so he uses weed block cloth instead. I could go on, but I digress.

Sorry Aaron,

My bad. I thought that I had read that he put the cloth over the vapor barrier to protect it. I doubt that the cloth is an approved vapor barrier.....

I need to learn how to read.........

This might help.

I like VH's solution, or is that preparation? Do they come in .357?

I don't see the problem. This sound like at standard plenum air space.

Best

Ron

Fans in crawlspaces are bad. You end up sucking humid and or warmer air back in to the cooler crawlspace and then you have to deal with the moisture problem from condensation.

M1305.1 Appliance access for inspection service, repair and
replacement.

Appliances shall be accessible for inspection, service,
repair and replacement without removing permanent construction,
other appliances, or any other piping or ducts not
connected to the appliance being inspected, serviced, repaired or
replaced. A level working space at least 30 inches deep and 30
inches wide (762 mm by 762 mm) shall be provided in front of
the control side to service an appliance. Installation of room
heaters shall be permitted with at least an 18-inch (457 mm)

working space. A platform shall not be required for room heaters.

M1305.1.4 Appliances under floors.

Underfloor spaces
containing appliances requiring access shall have an unobstructed
passageway large enough to remove the largest
appliance, but not less than 30 inches (762 mm) high and 22
inches (559 mm) wide, nor more than 20 feet (6096 mm)
long when measured along the centerline of the passageway
from the opening to the appliance. A level service space at
least 30 inches (762 mm) deep and 30 inches (762 mm)wide
shall be present at the front or service side of the appliance.
If the depth of the passageway or the service space exceeds
12 inches (305 mm) below the adjoining grade, the walls of
the passageway shall be lined with concrete or masonry
extending 4 inches (102 mm) above the adjoining grade in
accordance with Chapter 4. The rough-framed access opening
dimensions shall be a minimum of 22 inches by 30
inches (559 mm by 762 mm), where the dimensions are
large enough to remove the largest appliance.

Exceptions:

1. The passageway is not required where the level
service space is present when the access is open,
and the appliance can be serviced and removed
through the required opening.
2. Where the passageway is unobstructed and not
less than 6 feet high (1929 mm) and 22 inches wide
for its entire length, the passageway shall not be

limited in length.

Originally Posted by Ron Bibler

I don't see the problem. This sound like at standard plenum air space.

Best

Ron

RB: Of course, nearly anything could be "standard" in CA. I'm not familiar with what passes for a building code there, but IRC and the design professional here require 6-mil poly on the ground. Now, in the Land of Arnold weed block cloth may actually be 6-mil ploy, but it isn't here in the real world.

I am certain that the Terminator would crawl through sharp rocks and jump up unphased. After his crawl though, the 6-mil poly would be replete with holes, thereby rendering it ineffective.

JP: I hesitate to use the citation regarding "level", as I also must address with this bright bulb the fact that he has not installed the required sump pumps and the soil in the crawl will need to be sloped (I was tempted to use "canted", but decided to pass) toward the pumps.

I like the idea of the "unobstructed" issue, but am not certain I can successfully deem gravel on grade and obstruction. However, I will certainly try if no better argument arises.

I understand what you are saying. But sharp rocks I think thats all there is under almost every home. We see this type of set up all the time in Calif. Infact it works very well...

Keeps the weeds down

Best

Ron

Originally Posted by Ron Bibler

I understand what you are saying. But sharp rocks I think thats all there is under almost every home. We see this type of set up all the time in Calif. Infact it works very well...

Keeps the weeds down

Best

Ron

RB: If the vegetation is removed as required by IRC and the vapor barrier is in place as required by the same code, weeds should not grow. This is especially true in this case where there will be no foundation vents to allow light to enter.

But, even if a weed or two sprouts here and there, what's the harm?

Ever look under the plastic You will find all kinds of plants doing just fine.

Best

Ron

Originally Posted by Ron Bibler

Ever look under the plastic You will find all kinds of plants doing just fine.

Best

Ron

RB: Not a botanist and never lift that particular skirt.

Originally Posted by Ron Bibler

I understand what you are saying. But sharp rocks I think thats all there is under almost every home. We see this type of set up all the time in Calif. Infact it works very well...

Keeps the weeds down

Best

Ron

Ron,

"Sharp" rocks would tear the plastic sheeting, making it into a weed-block material but no longer a moisture barrier.

The only way for the sharp rocks to keep the weeds down would be for: a) the rocks to have cut through the plastic, b) the weeds to have grown up through the plastic where it was but by the sharp rocks.

Aaron,
obstruction
One entry found.

Main Entry: ob·struc·tion
Pronunciation: \əb-ˈstrək-shən, äb-\
Function: noun
Date: 1533
1 a: the state of being obstructed ; especially : a condition of being clogged or blocked b: an act of obstructing
2: something that obstructs

Do not sharp rocks create an obstruction to access and removal? And therefore would not be "un"obstructed?

Originally Posted by Scott Patterson

Fans in crawlspaces are bad. You end up sucking humid and or warmer air back in to the cooler crawlspace and then you have to deal with the moisture problem from condensation.

The moisture in most crawls is much, much greater than and moisture being drawn in from outside. At the least it reduces the moisture in the crawl to a lower point. Stagnant air sitting is a crawl when the soil is almost sopping wett is a far greater concern than that humidistat fan kicking on and after much of than ground moisture is gone shuts off because the moisture level has dropped.

This is an age old argument that no matter what group throws their 2 cents worth in and their 100 year moisture in crawl studies never addressed. Ground water, or poor drainage around the home water, sitting in a crawl is far worse than anything you can draw inside. Again the fans work on a humidistat. Once the humidity is down from where it was it shuts off. You want even more moisture gone then set the stat lower so it runs longer and dries it out more.

Some warm or even hot humid air getting sucked though the crawl is far less detrimental than a moisture (maybe at a cooler temp) just sitting there. Once that fan shuts down the crawl temp cools to the same temp as the crawl. When moisture builds up in the crawl the fan kicks back on, reduces the moisture level and then shuts off.

As I have stated a multiple amount of times in the past is to remove the cause of water in a crawl as you would remove the source of water in a wall that is causing mold. If you have to cant the soil or should I say slope the soil in a crawl so the water goes to one end into a sump then so be it, but remove the water and solve the problem with it getting in there. But is saying that you are still going to have high moisture/humidity levels in the crawl if water is always getting in so vents, fans, need I say more.

Originally Posted by Jerry Peck

Ron,

"Sharp" rocks would tear the plastic sheeting, making it into a weed-block material but no longer a moisture barrier.

The only way for the sharp rocks to keep the weeds down would be for: a) the rocks to have cut through the plastic, b) the weeds to have grown up through the plastic where it was but by the sharp rocks.

Aaron,
obstruction
One entry found.

Main Entry: ob·struc·tion
Pronunciation: \əb-ˈstrək-shən, äb-\
Function: noun
Date: 1533
1 a: the state of being obstructed ; especially : a condition of being clogged or blocked b: an act of obstructing
2: something that obstructs

Do not sharp rocks create an obstruction to access and removal? And therefore would not be "un"obstructed?

JP: I agree with your reasoning and will present the argument accordingly and with verve. Maybe even with a few unobstructed expletives.

The point is that there is not one sub-structure that i have been in 30 years of going under homes that did not have some sharp rocks, or other sharp construction debris... Its not like you are trying to give 100% coverage of the soil any ways. If this is your objective then you need to be looking at some thing like these photos.

You can't rip this stuff and its very hard to cut.

And yes this stuff has rocks under it.

Best

Ron

Originally Posted by Ron Bibler

Its not like you are trying to give 100% coverage of the soil any ways.

Yeah, that is what you are trying to do.

Originally Posted by Jerry Peck

Yeah, that is what you are trying to do.

JP: Agreed, except that the code requires not just 100% coverage, but overlaps in that coverage as well.

Originally Posted by Jerry Peck

Yeah, that is what you are trying to do.

Jerry you are taking my words out of context...

Best

Ron

Originally Posted by Ron Bibler

Ever look under the plastic You will find all kinds of plants doing just fine.

Best

Ron

The only plants I ever see growing in a crawlspace would be mushrooms.
Clear poly doesn't stay clear for long when it's laid on dirt.

Forget the sharp rocks and spread concrete, please.

Originally Posted by A.D. Miller

JP: Agreed, except that the code requires not just 100% coverage, but overlaps in that coverage as well.

That's how we show it here in Upstate NY.

When did "code" begin requiring any moisture barrier other than in closed crawlspace?

Originally Posted by Vern Heiler

When did "code" begin requiring any moisture barrier other than in closed crawlspace?

VH: If you read the posts in this thread you will see that we are indeed discussing a closed crawl space.

Originally Posted by A.D. Miller

Last one for today, I promise.

Idiot architect (I should not single him out, this happens all the time) specifies "6-mil polyethylene with clean gravel above" as a crawl space covering. The gravel is not specified, other than "clean". So builder boy uses crushed rock. He also decides that the rock will tear the poly, so he uses weed block cloth instead. I could go on, but I digress.

The question is this: once they install the sump pumps and ventilation fans that they "forgot to install" (just like they "forgot" to install foundation vents), they will have mechanical equipment in the crawl space which will require servicing. There will be a hospital visit immediately following each service call thanks to the crushed rock.

Give me a code bullet to kill this guy with, please!

And, did I mention? 15,000 s.f. new construction? What is this world coming to??????

A.D. OH!