Thread: Wood floor over vented crawlspace in FL

I recently inspected a home near Orlando, FL, that was originally constructed in the 1980's, with a vented crawlspace, fiberglass insulation between floor joists, with craft paper facing down and plywood attached to bottom edge of floor joists. Also, portions of the crawlspace is lower than the exterior grade and there are open 1/8 inch gaps between the sheets of plywood.

The home had water intrusion during the 2004 Hurricane Charlie, including water damage to the 1st floor wood flooring. When the home was repaired, the 1st floor air handler and most of the 1st floor ductwork was moved to the crawlspace, however, to installed the floor registers, sections of plywood and floor insulation were removed and not reinstalled.

Dr. Joseph Lstiburek's Top Ten Dumb Things To Do In the South, includes venting crawlspaces, insulating floors above crawlspaces, installing HVAC ducts and equipment in crawlspaces.

All of the replaced wood flooring is curling or cupping, the homeowner has ask me to determine the cause and the remedy. Since the originally installed wood flooring had no previous flooring issues, it appears, the crawlspace venting, insulated floors and negative crawlspace drainage, was not a problem.

By moving the ducts beneath the house, they were able to raise the ceiling height, so I know the homeower would prefer to keep the ductwork beneath the house. With that in mind is his most effective cure, to seal crawlspace, correct drainage and remove floor insulation?

Thanks for your help.

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Crawlspace issues are usually specific to each house.

I bet the new hardwod flooring was very dry when it was installed then it buckled as it took on the normal moisture present in your area.

Hardwood flooring has to be taken out of the packaging and left on site until it adapts. This can take anywhere from 10 days to 30 days. Its not a good idea to install hardwood flooring during the extreme parts of the year (driest or most humid months).

with craft paper facing down and plywood attached to bottom edge of floor joists.

JW: That installation is ass-backward.

With that in mind is his most effective cure, to seal crawlspace, correct drainage and remove floor insulation?

JW: All of the above, and as BK stated, find a floor installer who understands the concept of acclimatizing the flooring prior to installation.

Originally Posted by Jack Wingo

I recently inspected a home near Orlando, FL, that was originally constructed in the 1980's, with a vented crawlspace, fiberglass insulation between floor joists, with craft paper facing down and plywood attached to bottom edge of floor joists. Also, portions of the crawlspace is lower than the exterior grade and there are open 1/8 inch gaps between the sheets of plywood.

The home had water intrusion during the 2004 Hurricane Charlie, including water damage to the 1st floor wood flooring. When the home was repaired, the 1st floor air handler and most of the 1st floor ductwork was moved to the crawlspace, however, to installed the floor registers, sections of plywood and floor insulation were removed and not reinstalled.

Dr. Joseph Lstiburek's Top Ten Dumb Things To Do In the South, includes venting crawlspaces, insulating floors above crawlspaces, installing HVAC ducts and equipment in crawlspaces.

All of the replaced wood flooring is curling or cupping, the homeowner has ask me to determine the cause and the remedy. Since the originally installed wood flooring had no previous flooring issues, it appears, the crawlspace venting, insulated floors and negative crawlspace drainage, was not a problem.

By moving the ducts beneath the house, they were able to raise the ceiling height, so I know the homeower would prefer to keep the ductwork beneath the house. With that in mind is his most effective cure, to seal crawlspace, correct drainage and remove floor insulation?

Thanks for your help.

As it has been said the insulation is backwards. But even a larger problem is the insulation itself. It needs to be removed. The insulation is holding the cooler air from the house (you are in a cooling climate) up at the subfloor and the humid warmer air from the crawlspace is on the other side. The two are meeting in the middle and you have the perfect recipe for condensation. Removing the insulation will help to solve this part of the problem.

When a floor cups, it is telling you that you have water from the underside. I would also check to see if they installed a moisture barrier on the subfloor before the put the wood floor down. Although this is not required it is recommended by the vast majority of wood floor manufacturers.

A full moisture barrier needs to be installed over the ground in the crawlspace.

Sealing the crawlspace could solve or even make the problem worse!

Advanced Energy in North Carolina has a great deal of information on Southern Crawlspace design.

Sealing the crawlspace could solve or even make the problem worse!

SP: Not if it is done properly.

Air handler and duct work moved into the crawl.


That should about tell it all right there.



As far as the insulation it is upside down.


As far as your other staement

"Dr. Joseph Lstiburek's Top Ten Dumb Things To Do In the South, includes venting crawlspaces, insulating floors above crawlspaces, installing HVAC ducts and equipment in crawlspaces."

As far as the only smart thing he said was the part about putting an air handler in the crawl along with the duct work and maybe the part about insulating a crawl between the floor joist. The insulation vapor barrier or not (it is upside down) does not allow the air to move and the wood keep relatively dry.

Other than that the DR. in front of his name is misleading. It does not make him an expert about anything at all. Venting or not venting depends completely on that particular crawl.

Sealing the crawl could be the one worse mistake they make.


I am so tired of hearing of folks and the certs or edumication and that makes them the expert.

Obviously the one item that made the huge difference was the ducts and the air handler in the crawl. It is either leaky as hell with cold conditioned air blowing out every where or just the freezing ars cold unit and the duct has changed the entire crawl climate. That is the major reason for what is happening. The insulation upside down (as you said) never made a difference in the past so it should not make a difference now with the exception of adding the HVAC system to the crawl.

When ever I pass anything along to a client it is based on the what is happening now and in this case, what was happening before.

What appears to be happening is the air from outside is being condensed in the crawl (from cold air in the crawl) and keeping everything wet. If it were just humid air drafting thru the crawl this would not be happening because it would be a constant. The change is the HVAC unit in the crawl. Get it out of there. Put a radiant barrier in the attic and then move the unit to the attic.

Anyway you do it now it is going to cost thousands for a stupid mistake by someone else. They are ultimately responcible. Why you might say. Because they had no freaking clue as to thinking ahead as to the effect this would have on the rest of the entire system. What system you might ask????

The home.

Originally Posted by Jack Wingo

I recently inspected a home near Orlando, FL, that was originally constructed in the 1980's, with a vented crawlspace, fiberglass insulation between floor joists, with craft paper facing down and plywood attached to bottom edge of floor joists. Also, portions of the crawlspace is lower than the exterior grade and there are open 1/8 inch gaps between the sheets of plywood.

The home had water intrusion during the 2004 Hurricane Charlie, including water damage to the 1st floor wood flooring. When the home was repaired, the 1st floor air handler and most of the 1st floor ductwork was moved to the crawlspace, however, to installed the floor registers, sections of plywood and floor insulation were removed and not reinstalled.

Jack,

The above part tells me that Dumb and Dumber were the designers and contractors on that job.

First and foremost: "The home had water intrusion during the 2004 Hurricane Charlie, including water damage to the 1st floor wood flooring." that is, to me, telling me that either: 1) the walls (windows, doors, walls, roof, you name it) leaked, OR - AND/or - , 2) the water level outside rose to the height of the first floor.

*IF* 2) above, then NOTHING should have been moved DOWN to the crawlspace, EVERYTHING down there should have been moved UP into the house.

The worst part is that "The home had water intrusion during the 2004 Hurricane Charlie, including water damage to the 1st floor wood flooring." AND NOTHING was done to repair the moisture/water soaked items below, such as the insulation, that plywood, the wood floor framing, etc.

Your information did not give enough insight as to which happened - "water intrusion" from leaks or from rising water, or both - to make educated guesses on. Which leaves us all making uneducated guesses, which is like admitting " We don't know nuttin', but this is what NEEDS to be done ... even though we don't know nuttin'. "

Before addressing any of the other information you first need to find out what caused the "water intrusion". Was it "leakage" or "flooding" (rising water)?

Originally Posted by A.D. Miller

SP: Not if it is done properly.

Isn't that true with just about everything!

Jerry,
The water intrusion was due to a tree damaging a portion of 2nd floor roof and wind driven rain that entered the edges of 2 domers. They did have water damage to various areas, mostly on the 2nd floor, but water did mitigrate to the 1st floor. The homeowners did have the home inspected and remediated prior to repairs, but did not have house retested after repairs completed.

Apparently, there was mold problems and as a result, the homeowners have had health issues and can not live in house. Prior to my inspection, the homeowner had an air quality inspection, however, the inspection results were not complete prior to my inspection.

I gather more information regarding extend of damage, repairs made and results of air quality test. Should get back to you in a few days.
Thanks-Jack

Originally Posted by Jack Wingo

Jerry,
The water intrusion was due to a tree damaging a portion of 2nd floor roof and wind driven rain that entered the edges of 2 domers. They did have water damage to various areas, mostly on the 2nd floor, but water did mitigrate to the 1st floor. The homeowners did have the home inspected and remediated prior to repairs, but did not have house retested after repairs completed.

Apparently, there was mold problems and as a result, the homeowners have had health issues and can not live in house. Prior to my inspection, the homeowner had an air quality inspection, however, the inspection results were not complete prior to my inspection.

I gather more information regarding extend of damage, repairs made and results of air quality test. Should get back to you in a few days.
Thanks-Jack

This has the sound of a lawsuit in the makings. If you are not comfortable with the idea of doing EW work you might want to back off and refer another inspector who does EW work.

I have been researching solutions and found this government research. It is my understanding that they actually used a new development with test houses to measure different moisture levels. I cannot find that site, but it seems to have been summarized here.

Energy Savers: Crawl Space Insulation

Crawl Space Insulation

If you properly insulate your crawl space—in addition to air sealing and controlling moisture, you will save on energy costs and increase your home's comfort.
Before insulating or deciding whether to add insulation to your crawl space, first see our information about adding insulation to an existing house or selecting insulation for new home construction if you haven't already.
How to insulate a crawl space depends on whether it's ventilated or unventilated. Traditionally, crawl spaces have been vented to prevent problems with moisture; most building codes require vents to aid in removing moisture from the crawl space. However, many building professionals now recognize that building an unventilated crawl space (or closing vents after the crawl space dries out following construction) is the best option in homes using proper moisture control and exterior drainage techniques. There are two main reasons for this line of thinking:

• Ventilation in the winter makes it difficult to keep crawl spaces warm
• Warm, moist outdoor air brought into the crawl space through foundation vents in the summer is often unable to dehumidify a crawl space. In fact, this moist outdoor air can lead to increased moisture levels in the crawl space.

Insulating an Unventilated Crawl Space

If you have or will have an unventilated crawl space, then your best approach is to seal and insulate the foundation walls rather than the subfloor. The advantages of insulating the crawl space are as follows:

• You can avoid the problems associated with ventilating a crawl space.
• Less insulation is required (around 400 square feet for a 1,000-square-foot crawl space with 3-foot walls.)
• Piping and ductwork are within the conditioned volume of the house so they don't require insulation for energy efficiency or protection against freezing.
• Air sealing between the house and the crawl space is less critical.

The disadvantages of insulating a crawl space include the following:

• The insulation may be damaged by rodents, pests, or water.
• A radon mitigation system will require ventilation of the crawl space to the exterior. Not planning for radon-resistant construction may necessitate air sealing the floor to mitigate the radon through ventilation.
• The crawl space must be built airtight, and the air barrier must be maintained.
• The access door to the crawl space must be located inside the home through the subfloor unless an airtight, insulated access door in the perimeter wall is built and maintained.

Steps for Installing Crawl Space Wall Insulation

1. Review plans for this method of foundation insulation with pest control and local building officials to ensure code compliance.
2. Eliminate or seal the foundation vents.
3. Ensure that combustion furnaces and water heaters located in the crawl space are sealed-combustion units equipped with a powered combustion system.
4. Seal all air leaks through the exterior wall during and after construction, including the band joist.
5. Locate the crawl space access inside the home or install an access through the perimeter that will remain airtight after repeated use.
6. Install rigid foam board or batt insulation—exterior foam, interior foam, or interior batt—to achieve complete insulation coverage. Insulate the band joist with batt insulation, as well as the crawl space access if it's located in the wall.
7. Install a continuous termite shield between the band joist and masonry foundation wall that covers the wall insulation and extends completely outside (or leave a 2- to 4-inch insulation gap at the top for termite inspection).
8. Install a supply outlet in the crawl space, relying on the leakiness of the floor to provide the return air path.

Steps for Installing Underfloor Insulation

1. During the early phases of construction, the builder should inform all subcontractors (plumbing, electrical, HVAC, etc.) that they need to keep the space between the floor joists as clear as possible. Run drain lines, electrical wiring, and ductwork below the bottom of the insulation so that a continuous layer of insulation can be installed. For freeze protection, supply plumbing may be located within the insulation. The best approach is to run supply plumbing together in a few joist spaces. The insulation can be split and run around the plumbing.
2. Seal all air leaks between the conditioned area of the home and the crawl space. High-priority leaks include holes around bathtub drains and other drain lines, plenums for ductwork, and penetrations for electrical wiring, plumbing, and ductwork (including duct boot connections at the floor).
3. Insulation batts with an attached vapor barrier are typically used to insulate framed floors. Obtain insulation with the proper width for the joist spacing of the floor being insulated. Complete coverage is essential. Leave no insulation voids. The batts should be installed flush against the subfloor to eliminate any gaps, which may serve as passageways for cold airflow between the insulation and subfloor. The batts also should be cut to the full length of the joist being insulated and slit to fit around wiring and plumbing.
4. Insulate the band joist area between the air ducts and the floor as space permits. Use insulation hangers (wire staves) spaced every 12-18 inches to hold the floor insulation in place without compressing the insulation more than 1 inch.
5. The orientation of the vapor barrier depends on the home's location or climate. In most of the country, the vapor barrier should face upward. However, in certain regions of the Gulf states and other areas with mild winters and hot summers, it should face downward.
6. Insulate all ductwork in the crawl space.
7. Insulate all hot and cold water lines in the crawl space unless they are located within the insulation.
8. Close crawl space vents after ensuring that the crawl space and all the construction materials are dry.

For insulating truss floor systems, it's better to install netting or foam board insulation to the underside of the floor trusses. Then, fill the space created between the netting or insulation and subfloor with loose-fill insulation.
Insulating a Ventilated Crawl Space

Here are some guidelines to follow for insulating a ventilated crawl space:

1. Carefully seal any and all holes in the floor above ("ceiling" of the crawl space) to prevent air from blowing up into the house.
2. Insulate between the floor joists with rolled fiberglass. Install it tight against the subfloor. Seal all of the seams carefully to keep wind from blowing into the insulation. Also, adequately support the insulation with mechanical fasteners so that it will not fall out of the joist spaces in the years to come. DO NOT just rely on the friction between the fiberglass and wood joists to secure it in place.
3. Cover the insulation with a house-wrap or face it with a vapor barrier. The orientation of the vapor barriers depends on the home's location or climate. In most of the country, the vapor barrier should face upward. However, in certain regions of the Gulf states and other areas with mild winters and hot summers, it should face downward.
4. Install a polyethylene vapor retarder, or equivalent material, over the dirt floor. Tape and seal all seams carefully. You may also cover the polyethylene with a thin layer of sand or concrete to protect it from damage. Do not cover the plastic with anything that could make holes in it, such as crushed gravel. Be sure the headroom of the crawl space meets local code regulations if you are considering pouring a concrete slab.

Other Considerations

As mentioned above, when properly insulating a crawl space, you also have to consider moisture control measures and air sealing.
Finally, you need to consider radon resistance or control when installing any type of foundation. See the Learn More resources on the right side of this page (or below if you've printed it out) for more information about radon and radon-resistant construction techniques.

KK:

Nice post, but you have lost the majority of your audience.

You will never convince the most of this lot by simply presenting them with the facts. Many would not recognize a fact if it bit them in their ass.

Further, you fritter away your time by regaling them with the credentials of the fact finders. Most have no credentials and see little or no worth in those which others have obtained.

Remember that, statistically speaking, 80% of the population of this country believes in unmitigated religious BS. Their core philosophy is based upon baseless assumptions. You are dealing with lizard people. Appeal to their reptilian brains and you have a chance of reaching them.

Small steps.

Originally Posted by A.D. Miller

KK:

Nice post, but you have lost the majority of your audience.

You will never convince the most of this lot by simply presenting them with the facts. Many would not recognize a fact if it bit them in their ass.

Further, you fritter away your time by regaling them with the credentials of the fact finders. Most have no credentials and see little or no worth in those which others have obtained.

Remember that, statistically speaking, 80% of the population of this country believes in unmitigated religious BS. Their core philosophy is based upon baseless assumptions. You are dealing with lizard people. Appeal to their reptilian brains and you have a chance of reaching them.

Small steps.

See what credentials get you

No one is saying that credentials do not hold water. I think what is being said when anyone makes that statement is that just because one has a particular credential does not make them the expert in a particular subject matter.

Case in point. I have met many with credentials that are inspectors that are terrible inspectors. They get so hell bent when they find a particular concern and delve so deap that things around them escape finding. Being book smart does not always make someone street or worldly smart.

I have seen folks seal up crawls with litterally saturated mud under the plastic. Yeah think they would have solved the water problem first then sealed the crawl. Then you have to think of that lovely crawl that gets sealed up and then never looked into for a couple years or more only to find out that there has been a plumbing leak for the past couple years in the crawl and they turned it in to a wonderful fish pond with there plastic coating.

Is it always good to seal a crawl

Maybe in a perfect worlde with perfect maintenance. You know that aint happening. Other than that....Absolutely not. Improvements to the crawl...absolutely

The above is my perfect case in point fore those with credentials. That point above just blew the case for sealing up all crawls a laughing matter.

The amount of folks that will ever venture their head into a crawl or have someone else go down there every few months, at the longest interval, is absolutely no one. Well, maybe a chosen few inspectors.

No one is picking on everyone with credentials. What is happening is the fact that credentials may or may not add up to a hill of beans in the common sence department.

What is that saying about trees and a forest.

Think *real world* before blanket fixes are thrown out for every similar concern.

Good iseas are not always the best logic. Like I said in a post above....Dr...whats that....Dumb Redneck They are just a couple letters. My friends that are Doctors are referred to Frank and John and Anna...Not Dr Frank and Dr John and Dr Anna. What they achieved in school is not who they are but what they became in the employed world as an adult.

I carried a rifle and some nasty explosives once upon a time. Did that make me a hero...Not... Just helped keep me and others alive and of course on the other end...NOT

I have seen folks seal up crawls with litterally saturated mud under the plastic. Yeah think they would have solved the water problem first then sealed the crawl.

Ted there are times no matter what you do the water table is going to be high and the soil will be muddy or the lay of the land/lot cannot be altered to the point of stopping strata saturation. Sealing the crawl space solves that problem and it doesn't matter if it stays muddy or not. As long as the footer has bearing let it rip.
If you treat your home as a boat moisture problems will be Nil.

As for the pictures I don't see termite inspection area. You can't run the barrier up and over the foundation.

Ted there are times no matter what you do the water table is going to be high and the soil will be muddy or the lay of the land/lot cannot be altered to the point of stopping strata saturation. Sealing the crawl space solves that problem and it doesn't matter if it stays muddy or not. As long as the footer has bearing let it rip.
If you treat your home as a boat moisture problems will be Nil.

MS: Best of luck getting TM to follow your thinking here. I have given up on the boy. Let me know how it works out . . .

Originally Posted by Mike Schulz

Ted there are times no matter what you do the water table is going to be high and the soil will be muddy or the lay of the land/lot cannot be altered to the point of stopping strata saturation. Sealing the crawl space solves that problem and it doesn't matter if it stays muddy or not. As long as the footer has bearing let it rip.
If you treat your home as a boat moisture problems will be Nil.

As for the pictures I don't see termite inspection area. You can't run the barrier up and over the foundation.

Hey Mr Mike

You will also read into most of my posts that every crawl needs its own eval because it has its own set of circumstances.

AS far as saturated soil ....How about a slope and a sump to draw as much of that water out as possible.

Now if you are talking a new home and the soil is that saturated then you are building on a wet land area that should not be allowed anyway. If it is that saturated in an existing home then you better have piers all the way to bedrock or the home is going to continue to sink.

I inspected a home in Mineral Wells Texas where the home has sunk a foot it 40 years and will continue to sink. In this case the home was to far gone and needed to be torn down.

Unlike what Aaron thinks I actually do listen to what everyone has to say and respond in kind.

And as my typical statement for crawl spaces....Every crawl has its own set of needs which creates a certain set or order of fixes.

Every crawl needs to be evaluated individually.

Good Night Aaron !!!!!!!!!!!!!!!!!

I guess this is why all good inspectors should have a moisture meter as part of the arsenal they carry to an inspection. Then you do not have to guess why the floor is warping or curling. Some of you amaze me with how you try to make a simple solution or finding, so complicated. You must be lucky enough to charge by the hour for an inspection. The vapor barrier always goes toward the conditioned area, that is how it keeps moisture from entering the inside of the house, building, ect. A simple vapor barrier of 4-6 mil plastic over the dirt or gravel under the house usually is sufficient enough to prevent moisture to accumulate on the insulation between the floor joists. Get that you put the moisture barrier before the area that you want to keep dry. If the building does not have vents it is ok to put a small amount of conditioned air into the space (¼ air change an hour) you may need to run a pipe thru the roof or wall to allow for an air change. A simple 4” sewer pipe running from the crawl space thru the roof will work maintenance free to create an air change needed. If you live in the desert or areas where the humidity stays low you should not have to worry about moisture problems.

Originally Posted by Cobra Cook

Some of you amaze me with how you try to make a simple solution or finding, so complicated.

Somethings are more complicated than what some people think.

The vapor barrier always goes toward the conditioned area, that is how it keeps moisture from entering the inside of the house, building, ect.

First, the facing on the insulation is a vapor *retarder*, not a vapor *barrier*, secondly, it goes on the "warm in winter side", which is the conditioned side, nonetheless, though, it is the "warm in winter" side ... just "uncomplicating" what you stated.

Jerry correct me if I'm wrong A barrier is the paper face attached to the Batt and that paper face retards moisture hence the terms Vapor Barrier and or Vapor Retarder

The paper Retarder/barrier should always face the conditioned space.

Originally Posted by Mike Schulz

Jerry correct me if I'm wrong A barrier is the paper face attached to the Batt and that paper face retards moisture hence the terms Vapor Barrier and or Vapor Retarder

The paper Retarder/barrier should always face the conditioned space.

MS:

VAPOR RETARDER.

A vapor resistant material, membrane
or covering such as foil, plastic sheeting, or insulation facing
having a permeance rating of 1 perm (5.7  10-11kg/Pa  s m2) or
less, when tested in accordance with the dessicant method
using Procedure A of ASTM E 96. Vapor retarders limit the
amount of moisture vapor that passes through a material or wall
assembly.

An acceptable vapor retarder can be any material that
has been tested in accordance with the dessicant
method using Procedure Aof ASTM E 96 that does not
have a permeance rating greater than 1.0. Permeance
is a measure of water vapor transmission (wvt) rate in
grains per hour per square foot divided by the vapor
pressure difference in inches of mercury. Materials
tested to the standard are papers, plastic films, asphalt-
saturated construction papers and sheet materials.
Vapor retarders are installed on the warm-in-winter
side of walls, floors and ceilings of the building’s
thermal insulation.

VAPOR BARRIER. Same thing. 1.0 perm or less.

JP may have been out speed testing his cat and blown out a few synapses in the process. He'll recover . . .

Originally Posted by A.D. Miller

VAPOR BARRIER. Same thing. 1.0 perm or less.

JP may have been out speed testing his cat and blown out a few synapses in the process. He'll recover . . .

Aaron,

A vapor BARRIER is ... well ... a "barrier", unlike a vapor RETARDER which, as you so eloquently posted - "retards" the vapor flow, the vapor "barrier" creates a "barrier" to vapor.

Wrapping the house in a WRB creates a vapor retarder, as does wrapping the house in building paper felt.

However, wrapping the house is plastic sheeting creates a vapor barrier, which is no desirable.

"
How They Work

A vapor barrier or vapor diffusion retarder (VDR) is a material that reduces the rate at which water vapor can move through a material. The older term "vapor barrier" is still used even though it may inaccurately imply that the material stops all of the moisture transfer. Since everything allows some water vapor to diffuse through it to some degree, the term "vapor diffusion retarder" is more accurate.
"
Energy Savers: Vapor Barriers or Vapor Diffusion Retarders

Originally Posted by Jerry Peck

Aaron,

A vapor BARRIER is ... well ... a "barrier", unlike a vapor RETARDER which, as you so eloquently posted - "retards" the vapor flow, the vapor "barrier" creates a "barrier" to vapor.

Wrapping the house in a WRB creates a vapor retarder, as does wrapping the house in building paper felt.

However, wrapping the house is plastic sheeting creates a vapor barrier, which is no desirable.

"
How They Work

A vapor barrier or vapor diffusion retarder (VDR) is a material that reduces the rate at which water vapor can move through a material. The older term "vapor barrier" is still used even though it may inaccurately imply that the material stops all of the moisture transfer. Since everything allows some water vapor to diffuse through it to some degree, the term "vapor diffusion retarder" is more accurate.
"
Energy Savers: Vapor Barriers or Vapor Diffusion Retarders

JP: Don't take the matter up with me. I am simply quoting directly (mostly) from the IRC. Surely they cannot be wrong. Right?

JP: OK, just pulling your leg. I was temporarily suffering from decimal point creep. So then, a vapor impermeable material is a vapor barrier. That would be one with .01 perm or less. Right?

Originally Posted by A.D. Miller

JP: Don't take the matter up with me. I am simply quoting directly (mostly) from the IRC. Surely they cannot be wrong. Right?

Aaron,

"I am simply quoting directly (mostly) from the IRC."

Huh?

"directly" and "mostly" do not go together.

Besides, neither the IRC nor the IBC defines "vapor barrier" (I looked earlier).

"directly" and "mostly" do not go together.

JP: Though seemingly contradictory, they often go together quite nicely.

Besides, neither the IRC nor the IBC defines "vapor barrier" (I looked earlier).

JP: Me too, and you are right. That is why I manufactured that one out of whole (plastic-backed) cloth.

OHhh Contraire Oh mighty one

A vapour barrier is often used to refer to any material, typically a plastic or foil sheet, that resists diffusion of moisture through wall, ceiling and floor assemblies of buildings. Technically, many of these materials are only vapour retarders as they have varying degrees of permeability.

Originally Posted by Mike Schulz

OHhh Contraire Oh mighty one

A vapour barrier is often used to refer to any material, typically a plastic or foil sheet, that resists diffusion of moisture through wall, ceiling and floor assemblies of buildings. Technically, many of these materials are only vapour retarders as they have varying degrees of permeability.

MS: You might ought to duck about now. The storm is looming and headed your way.

Here it comes . . .

Quick. Go read this:

BSD-106: Understanding Vapor Barriers —

A.D thanks for the heads up but Jerry's always been good to me and I highly respect him and you. (gag) So bring it on Mr. Peck because I float like a butterfly and sting like a bee.......... I'll make gorilla cookies outtta ya!

OK had my fun.

If you look at the heading on each page " Vapor Barriers and Wall designs"

hence my post that it's can be called both. The coverage of the bays between the joist would be called a barrier and the material used is the retarder.

I know I am not the brightest bulb and Jerry will probably put my lights out but hey show me.........

Originally Posted by Mike Schulz

hence my post that it's can be called both.

Barriers are barriers to, in this case, vapor transmission.

Retarders are really what you are referring to as they retard the transmission of vapor.

Originally Posted by Jerry Peck

Barriers are barriers to, in this case, vapor transmission.

Retarders are really what you are referring to as they retard the transmission of vapor.

JP: OK then, if a "vapor barrier" can be a material that has a permeance rating of >0.0, how is it a true barrier?

Originally Posted by [B

A.D. Miller AKA BAGDAD BOB[/B] ;98082] Remember that, statistically speaking that BAGDAD BOB of the population of this country believes in his own unmitigated religious BS. His core philosophy is based upon baseless assumptions. You are dealing with a lizard man. Appeal to his reptilian brains and you have a chance of reaching them. Small steps.

L.O.L.


Back to the original post... Each home will present its own set of problems. to just take one approach and try to make that fit is like a dog and his tail. Round and round you go.

Each part of the home needs and inspection to find out if its part of the problem.

As Scott stated. " This has the sound of a lawsuit in the makings. If you are not comfortable with the idea of doing EW work you might want to back off and refer another inspector who does EW work."

Best

Ron