Crawlspace Vapor Barrier

Crawlspace Vapor Barrier

Crawlspace Vapor Barrier

crawlspace vapor barrier

More than 27 million homes in the U.S. have crawl spaces. And even though they’re exceedingly useful for extra home storage, it’s absolutely essential to keep them protected and dry to avoid the possibility of water and mold damage by installing a crawl space vapor barrier.

One method of controlling crawl space moisture is with a very simple and inexpensive project: laying out rolls of ordinary sheet plastic. Traditionally, this plastic has been called a vapor barrier, but this strategy has been retitled by the U.S. Department of Energy, which now defines it as a vapor diffusion barrier.

Some people even found a treasure (1)

According to the EPA (Environmental Protection Agency), 100% of all types of mold have the potential to cause some health effects. This can be minor to severe and even result in death in some rare cases.

In very warm, humid climates such as the Southeastern United States, crawlspace encapsulation is often the most effective way to solve and prevent moisture damage. Although crawlspace vents were originally designed to facilitate humidity exchange with the outside air, they may contribute to mold and rot in some geographic locations as saturated air condenses on crawlspace walls, foundation footings and the underside of flooring. This can lead to mold and mildew, waterlogged insulation — which reduces R-value and causes sagging — as well as poor air quality inside the home. While a professional mold remediation specialist can help you determine if a crawlspace encapsulation is the best way to address moisture problems in your crawlspace.

A clean, sealed crawl space with a high-performance vapor barrier can eliminate odors by impeding mold growth and improving indoor air quality, blocking entry to rodents and insects, and helping ease the latent load on your HVAC system – improving its efficiency. The resulting space can also provide additional room for storage beneath your home.

Even if you are a homeowner of a property in a dry climate, such as Arizona, moisture can be formed and reside in the soil. Even in Arizona, you can save an average of 15% annual energy savings (1) with a crawlspace vapor barrier because you are reducing moisture drastically.

A vapor barrier is a plastic liner that covers the dirt “floor” of your crawl space.  Its purpose is to block vapors and moisture in the soil from getting into your crawl space. 

Crawl space vapor barriers are durable membranes that work by preventing the infiltration of water vapor into the crawl space. And when you combine a crawl space vapor barrier with a waterproofing system, now you have the ultimate moisture protection of the crawl space from both liquid water and water vapor before it has the chance to enter your building.

Crawl space vapor barriers are durable membranes that work by preventing the infiltration of water vapor into the crawl space.   And when you combine a crawl space vapor barrier with a waterproofing system, now you have the ultimate moisture protection of the crawl space from both liquid water and water vapor before it has the chance to enter your building.

Proper insulation is critical in preventing certain structural and health problems. A crawl space vapor barrier can provide one of the easiest solutions in preventing moisture buildup in your crawlspace. It is simple and easy to install, and it may help improve the air quality of your house. The right crawlspace vapor barrier may also help reduce your energy costs, prevent mold growth, and prevent insect infestation. The best vapor barrier should be durable and long-lasting to ensure great value for your money and long-term moisture protection.

High-quality vapor barriers perform well even in the most difficult conditions. Poly vapor barriers are among the types of vapor barriers that you can find online. Their durability makes them popular and capable of offering the best value for your money. You can easily install sheets of vapor barrier on the floor of your crawlspace.

Consider buying a translucent poly crawl space vapor barrier so you can still see what is underneath and verify the presence of moisture without letting it into the crawlspace. You can run it along the length of your interior crawlspace foundation walls, then seal it with an adhesive compound. You can seal it to the floor with proper sealing tape.

The 6 mil, 8 mil, and 12 mil poly are fine as a crawlspace vapor barrier. Sometimes we did not recommend a DIY approach, like solving a sewage backup issue yourself. However in this case, a crawlspace vapor barrier is something you can install by yourself for sure.

How do Vapor Barriers Work?

One method of controlling crawl space moisture is with a very simple and inexpensive project: laying out rolls of ordinary sheet plastic. Traditionally, this plastic has been called a vapor barrier, but this strategy has been retitled by the U.S. Department of Energy, which now defines it as a vapor diffusion barrier.

But keep in mind that sheet plastic barriers tend to help only with the migration of gaseous water vapor up through the soil into the crawl space. They do not offer a remedy when water pools up in the crawl space. Pooling water comes from one of two sources:

  • A high water table or rainwater runoff may be causing water to pool in the crawlspace. In this case, you will need to hire a water remediation company. In most cases, they will dig a trench around the perimeter, add drain pipe, cover the pipe with drain gravel, and add a sump pump. In other cases, adding roof gutters and downspouts, and reconfiguring the earth grading may be enough to eliminate pooling water.
  • Leaking plumbing pipes, either water supply pipes or drain pipes, may be causing water to pool up in the crawlspace. Water leaking from damaged pipes above must be fixed before you put down a vapor barrier, or water will simply pool up on top of the plastic sheeting.

But provided problems with pooling water are addressed, adding a vapor diffusion barrier can go a long way toward preventing ongoing problems caused by moisture in a crawlspace.

These barriers are typically thick plastic materials that are installed across the soil to prevent ground moisture from ever entering the space at all.

Now, it’s important to know these barriers only work to prevent ground moisture from migrating into your crawl space and building. Water runoff or leaking pipes could still result in moisture in the crawl space area, which is another reason to consider combining your barrier with a waterproofing system.

Thickness Requirements For Crawlspace Vapor Barrier Sheets

Crawlspace vapor barrier sheets come in several thickness dimensions such as 6, 10 and 15, and 20 Mil thickness options. 15 and 20 mil work very well in floors while lower thickness sheets are recommended for walls.

It is imperative that the barrier possess a high puncture resistance as it is going to be exposed, rather than protected by a concrete floor slab, and can be susceptible to damage. The defining standard for plastic vapor retarders in contact with the ground is ASTM E1745 and 10, 15 and 20 mil far exceed the requirements of this standard.

Benefits From Installing A Crawlspace Vapor Barrier

One of the realities of constructing and repairing commercial buildings is forever remaining aware of the dangers of moisture. Rotting wood, mold, chipped paint and more are all risks of water entering the building in areas where it’s not wanted. One good leak could cause tens of thousands of dollars of damage, and an area that is already susceptible could cause multiple rounds of damage if not dealt with effectively. So prevention is key to protecting buildings from the havoc moisture can wreak.

Improvement Of the Crawlspace Air Quality

The airflow inside your crawlspace tends to flow inside the house because it goes up, so the crawl space air quality is key, as we described in this article how to improve it.

The air in your crawl space gets into your home.  Your house is made of materials that are porous: wood, concrete, even fiberglass insulation.  Additionally, the air that your HVAC unit circulates is pulled -at least in part- from the crawl space.  When you or someone in your family has a respiratory condition, air quality is a major concern.  If you’d like more specific details about air quality, we have an article that explores this topic here.   

Combat Moisture And Mold

Porous materials don’t just allow air circulation- they can also let in moisture.  And moisture is the enemy of a healthy home.  Damp air allows mold to grow, forces your HVAC system to work harder, contributes to the decay of your wooden flooring structure, and draws the interest of damaging insects.  (Not-so-fun fact: termites prefer wood softened by moisture.)  Want a more thorough explanation?  We describe how moisture in a crawl space causes damage in this post.

Moisture is one of the main foes of a home’s structure—potentially causing structural problems. Uncontrolled moisture can cause rot and decay in wood framing and other materials, and it fosters mold and mildew. The amount of moisture that is present determines if you can finish a basement, for example. Moisture also determines what type of below-grade flooring you are able to install. At its most extreme, moisture can even determine if the construction of a home or room addition is possible at all. Where moisture is a known problem, vapor barriers are integrated into wall, ceiling, and floor construction to combat the effects. 

One of the most serious problems caused by moisture is mold, mildew, and other fungi. Eliminating mold is difficult, and fully remediating mold-related problems is expensive. As a direct byproduct of crawl space moisture, mold can blacken floor cavity insulation and structural elements. Because there is often no light and only minimal ventilation in a crawl space, the problem never improves unless preventive or remediation methods are enacted.

Most people don’t think twice about the space beneath a building. They might store tools, parts, and random odds and ends down there, but other than when they have to retrieve those items, the crawl space is often a forgotten area.

Unfortunately, crawl spaces typically have dirt floors, which makes them prime culprits for moisture entering the commercial building.  That’s because moisture infiltration in the form of water vapor from the soil, if not contained, can slowly erode your building from the ground up. We’re talking structural damage, electrical shorts, pipe erosion, and the degradation of insulation and fiberglass. Not to mention the risk of heavy allergens (like mold spores and dust mite droppings) entering your living spaces.

Luckily, a crawl space vapor barrier offers a relatively simple solution to all of this.

Avoid Rotting

Structural elements of your house, such as joists, sills, posts, and beams, are made of wood. Being an organic material, wood will begin to rot when it comes into contact with water for prolonged periods.

Rotting is one of the causes that forces homeowners to sister affected joists with new ones like the cases of sistering 2×6 joists with larger ones.

Avoid Rodents And Other Animals

Animals of many types are drawn to water and can infest your home. These pests include carpenter ants, termites, rats, mice, snakes, even skunks and armadillos.

There are animals that burrow under concrete and that dig holes below the foundation. If we deprive them from water, they will have less reasons to stay there.

Step by Step Crawlspace Vapor Barrier Installation

Installing a vapor barrier is a project most homeowners can DIY.  You will need to calculate the square footage of your crawl space, so you can buy the appropriate amount of liner. You can find a wide range of options at home improvement stores, varying in color, material, and thickness. We recommend using a material with a 6 millimeter thickness; it will last longer than thinner liners.


The duration I expect is generally two working days for two workers.

So I have changed my previous statement and updated this article. The fact is that while one person performs the actual crawlspace vapor barrier installation, someone else has to do the passing of the tools, equipment, and materials through the usually limited workspace, tape seams, unroll the plastic, cut the sheet while someone else holds it, and so on.


It is not that the process is really difficult, but to install a crawlspace vapor barrier to actually have to crawl a lot of time on hands and knees.

Relatively high, I would say. The difficulty actually depends on the surface available to crawl comfortably and height of the crawlspace. If the area is cramped, installing a crawlspace vapor barrier becomes difficult.

DIY Cost

An estimated cost for a DYI approach is about $ 366 and your time, because I believe the duration in at least two working days. For the price, I consider a roll of crawlspace vapor barrier sheet of 1000 square feet and 12 mil of thickness.

Supplies And Materials Required

  • Plenty of lighting: flashlight, headlamps and/or utility lamps and maybe an extension cord.
  • Utility Knife
  • Drill with masonry bits
  • Measuring tape
  • Work gloves
  • Protective eye wear
  • Trash bags
  • Disposable breathing mask
  • Knee pads
  • Marker
  • A Caulk Gun 
  • Caulk
  • Ruler
  • -Hammer

So those were the tools needed, and the materials are

  • Crawlspace vapor barrier of minimum 6 mil for walls and 10, 15 or 20 mil for the floor
  • Vapor barrier seam tape
  • Double-sided construction tape
  • Termination bars or other mechanical fasteners
  • Concrete Screws, but this depends on the variations of the installation process.
  • Poly PVC tape like the Dow Weathermate Construction Tape, that is envisaged for crawlspace vapor barrier installation.

Step 1 Cleaning And Drying The Crawl Space Floor

The crawl space floor should be free of debris before you begin; any trash or failing insulation should be removed.

Crawl spaces are notoriously messy, as construction workers often toss discarded building materials in this space. Remove all debris, especially anything sharp that might puncture the plastic.

Look for is standing water – you don’t want to risk electrocution when you bring power and/or lighting into the area to get the job done.

To install the crawlspace vapor barrier, the workspace must be not only clean, but also dry.

It is best to begin with a crawl space that is as dry as possible. Methods for drying out a crawl space include: using a dehumidifier; setting up fans; removing wet materials, and using a pump to discharge any standing water.

You may need several days of effort to dry out the crawlspace before you venture down to lay vapor barriers over the ground.

Once it’s safe to enter, get that crawl space clean and clear of old poly, old/wet insulation, sharp rocks or other debris. Most building codes require the crawl space vapor barrier to be used on the ground. This even applies where you plan to use rigid insulation – install the vapor barrier on the ground first. For your own safety and comfort while working, get this surface as smooth as you can.

Step 2: Diagnosis Of The Crawlspace Issues

If you see signs of moisture around your home, call a licensed specialist to inspect and diagnose the problem. A professional will begin by inspecting the perimeter of the home and identifying any drainage issues, such as downspouts emptying too close to the foundation or any grading issues that may cause excessive water to enter the foundation. After identifying any issues on the outside of the home, they’ll enter the crawlspace and continue the inspection. A technician will typically use a moisture meter to take readings in all corners, as well as in the center of the crawlspace, to accurately gauge the overall moisture level. Sometimes moisture problems can still occur underneath your home even if water isn’t obviously pooling.

Step 3. Envisage A Mold Remediation Plan

After diagnosing any issues, the technician will determine a complete remediation plan, including whether or not they need to consult additional contractors, such as an electrician to install a ground-fault circuit interrupter (GFCI) to power a crawlspace dehumidifier, if needed.

Step 4 Reparation Of Structural Framing Elements

If the project requires it, a contractor may need to remove and replace any rotten wood in the crawlspace. This includes girders, floor joists, band joists and any rotten portions of the subfloor.

The worst problem you can see here is if you discover that you would need to sister floor joists because they are in bad condition, even if there is no building code forcing you to do so, or because some 2×6 joists would not suffice and you should sister them with 2×8 or 2×10 stronger joists.

Step 5: Application Of Fungicide Previous To The Crawlspace Vapor Barrier Installation

Moist environments generate fungal growth, and over time that fungus can lead to mold growth. Destroying the fungus beforehand is crucial. To kill the fungus, a technician may fog the crawlspace with a cold fogger machine filled with fungicide and scrub away any additional mold. They may also spray a fungus and mold prevention solution on all exposed wood.

Step 6 Address Vertical Surfaces First

With every house, you will encounter both outer support walls or columns and inner support piers and posts. For inner supports, cut the plastic sheeting to fit around them and seal the plastic against the supports using double-sided butyl tape. The goal is to provide a solid barrier against the ground. Where necessary, you can cut additional small pieces of plastic to seal any gaps and ensure a full barrier.

Around the perimeter of the crawlspace, extend the plastic sheeting at least 6 inches up the walls and secure it in place with double-sided butyl tape.

So that you’re most efficient with your material, you want to address the vertical surfaces first. The wall liner, which will be in a fixed position, will eventually tie into the horizontal ground cover.  So, the foundation walls are the best place to start to ensure excess material from your wall liner that turns onto the horizontal plane is overlapped with the ground vapor barrier at 6” (further explanation below).

Note, it’s important to leave a small gap at the top of your masonry walls to comply with your local building code. If your local building code does not specify the size of the gap to leave at the top of your masonry walls, leave three inches exposed for your termite inspector to do their job.

Start by applying the double-sided construction tape to the masonry wall. This super-sticky double-sided tape will effectively hang your installation in place until you can secure it with a mechanical fastener, such as a termination bar. Remove one side of the release liner a little bit at a time – move slowly along the wall, pressing the adhesive down firmly to ensure you’re moving in a straight line and to avoid a sticky mess.

Before removing the second release liner, to make sure the double-sided tape is really pressed into the wall, go back and forth over the double-sided tape with a rubber paint roller

Once you’ve applied the double-sided construction tape to your masonry wall, remove the exposed release liner to get ready to apply the vapor barrier.

Find a lightweight vapor barrier roll intended for vertical surface application. When looking for a vapor barrier manufacturer, it’s best to choose a product offered in a variety of rolls sizes and dimensions for ease of installation.

Unroll the vapor barrier along the vertical wall and apply it to the exposed, double-sided tape. Remember, this tape is sealing your crawl space from harmful moisture and odors, so apply it firmly and evenly around your masonry walls.

Make sure the vapor barrier extends higher than the double-sided tape.  Once the vapor barrier is stuck to the walls, you’ll want to secure it to the concrete with a mechanical fastener like termination bars. Most masonry screws require you to pre-drill a hole into the concrete wall.  If your termination bar has specific holes to hit, hold the term bar in place as a template to mark your holes with a marker.

Step 7 Sealing Of Crawlspace Ventilation: Optional Step In Some Cases

A technician may use a combination of rigid foam board and spray foam insulation if they determine they need to seal the crawlspace vents. This creates a crawlspace vapor barrier, increases the R-value of the crawlspace insulation and helps keep the temperature outside from impacting the temperature inside the crawlspace.

Step: 8 Attach Patches On The Pipeline

the most efficient way to encapsulate your crawl space is to address all the fixed position areas first so that holds true for  any pipes or other utility penetrations going from the ground into your house.

It’s best to work around these tricky spots with small detail patches of material. By sizing the vapor barrier to each penetration and cutting slits in the material to fit around tight spots, you’ll save a lot of time and effort trying to roll out material in these areas.

Then tape everything down with seaming tape. Remember, your completed installation will create a monolithic seal of your crawl space from vapor and soil gases. This includes your pipes and other penetrations, so seal the vapor barrier tightly around each pipe or penetration with the seam tape.

Step 9: Take Care Of The Columns

Prepare the columns the same way you prepared the foundation walls, using double-sided construction tape first, the same lightweight/smaller vapor barrier used on the vertical walls, and termination bars.

While your foundation walls probably included enough vapor barrier material to lay flat on the ground, this excess material can make columns a little trickier. At each corner of the column, cut a relief slit into the material so it lays flat. This will allow for a tight, four-sided encapsulation of the column while also providing you a nice seaming target to use when you roll out the material on the ground.

Step 10: Installation Of The Crawlspace vapor Barrier And Dehumidifier

Once you have a cleared work space, you will need to unroll the plastic sheeting and lay it out evenly across the “floor.”  The barrier should be thick enough that it doesn’t try to roll up on itself, but you may want to set a rock on it in the corners to secure it.

So you have to unroll the sheet (when the vapor barrier comes in a roll) and then you should proceed laying out in a leveled surface to perform the measurements.

Beginning at one side of the crawl space, lay down 6-mil or thicker polyethylene plastic over the entire crawl space. Cut the sheets to size, allowing 6 inches or more along walls. Overlap the seams by no less than 12 inches and secure them together with the poly PVC tape.

I recommend to use the Dow Weathermate Construction Tape. It is not that I have used them all and finally consider this one the best. It is just that I used it and worked well.

When spreading and laying out your crawl space moisture removal barrier, make sure to overlap all seams and tape them for maximum protection. Whether you’re overlapping two seams of material, running up against your walls or other detail work, be sure to overlap every seam by at least six inches.

The plastic should be secured at a distance of about six inches up the wall. 

Next, use the landscape fabric stakes to keep it protected for potential future disturbances.

Chances are that someone will have to slide around in the crawlspace later to fix a pipe or run a new cable. A few holes won’t make any difference in performance, and they’ll drain puddles if a heavy rain or leaky pipe leaves water on the plastic.

A technician may install a vapor barrier in your crawlspace to seal it off from excess humidity and install a dehumidifier. This works the same way as a dehumidifier in your home and maintains the ideal moisture level in the crawlspace to prevent complications from mold.

So why would we need a dehumidifier? well, we need to decide how the crawl space will be ventilated and conditioned after we complete our crawlspace vapor barrier installation project.

Step 11: Insulate Also Other Parts Of The Foundation

The next step is to cover any areas of your home’s foundation that may be exposed with one to one and a half inches of moisture proof insulation.

This helps to maximize the overall effectiveness of the basement waterproofing system and keep your home and belongings as safe as possible. 

These barriers also help to keep the increasing dampness in the concrete from making its way into your home’s crawl space. (Be aware that some brands may require a layer of drywall covering as well.)

Step 12: Insulation Of Rim Joists

Finally, you’ll need to insulate the rim joists using rigid insulation and caulking it into place to prevent air leaks. 

Once that is done, cap the foundation’s interior walls with a 6 ml layer of plastic in addition to galvanized flashing.

This prevents further moisture while serving as a termite barrier to keep your home pest-free as well.

Step 13: Follow Up Inspections

Although your crawlspace remediation solution may vary, a technician may offer one or more follow-up inspections after addressing the problem to ensure the dehumidifier is functioning properly.

Crawlspace Vapor Barrier Costs

A crawlspace vapor barrier costs an average of $ 1,17 per square foot with a recommended thickness of a range between 6 mil and 10 mil for walls and 12 to 20 mil for floors and lasts generally at least five years before it deteriorates by tear or by punctures.

There are also installations of 20 mil crawlspace vapor barrier sheets and they work excellent too, despite their costs. But these heavy sheets are only for the floor, while for vertical surfaces you should avoid thick liners.

This is a crawlspace vapor barrier Dura Skrim String Reinforced White Plastic Sheeting, of 20 mil thickness.

Consequences Of The Installation Of A Crawlspace Vapor Barrier

When you install (or replace) the vapor barrier in your crawl space you’ll notice a significant improvement in air quality.  The air in your home should become less humid, odors should dissipate, and your HVAC bill may even lower. 

When A Crawlspace Vapor Barrier Is Not Enough

Whereas the installation of a crawlspace vapor barrier is an acceptable solution in most cases, sometimes it is not enough.


Therefore, in this cases I will recommend waterproofing the crawlspace or improve the grading in your garden landscape. The latter is a solution that we recommend when we refer to ways to combat hydrostatic pressure in your foundation.

if you have more than just dampness in your crawl space, a vapor barrier is not sufficient.  It’s only meant to stop moisture, not water.  If you have puddles of water under your home when it rains, you will need waterproofing.  As rainwater collects in your crawl space, it will cause the vapor barrier to float around and render it ineffective. 

Improve The Slope

I recommended this solution also when addressing the problem of hydrostatic pressure in this article, where I describe it in more detail.

In addition to ensuring the proper humidity level is maintained in a crawlspace, it’s crucial that the landscape is sloped away from the home to divert water away from the foundation. The best time to address this issue is during the home’s construction. It may also be necessary to re-landscape after building on an addition, as digging a new foundation can change the slope of a parcel of land; newly compacted soil will begin to settle over time.


But a rotted roof and a massive storm aren’t the only ways moisture can enter a commercial building. 

Before You Begin

Prior to installing a crawl space barrier, you’ll want to remove any items being stored down there so that you can have free access to the ground you’ll be covering. It’s also important to dry out the crawl space to the best of your ability before starting.

This can be accomplished by removing any visible moisture sources (such as puddles) removing wet insulation and debris, and potentially even calling in a professional to scrub surfaces clean of mold.

Once the crawlspace is clean and relatively dry, you’ll want to gather your tools for installation. These are the items you will find yourself thankful to have on hand:

  • Lighting
  • Shovel
  • Pick axe
  • Utility knife
  • Replacement blades
  • Hammer drill
  • Reciprocating saw
  • Tape measurer
  • Screw driver set
  • Hammer
  • Wire staples
  • Respirator
  • Vacuum
  • Towels

How to Install Crawl Space Vapor Barriers

Now that you’ve got the crawl space clean and dry, and you’ve gathered all your tools, it’s time to begin.

Installation of PERMINATOR underslab vapor barrier can be completed in a few simple steps:

  1. Check local building codes for instructions on the gap you should leave unsealed from the top of the masonry wall, typically 3”. Apply PERMINATOR BUTYL TAPE around the foundation wall, where you’ll want the PERMINATOR underslab vapor barrier to attach.
  2. To prevent tenting, and for a cleaner overall look, consider fastening PERMINATOR underslab vapor barrier to the base of the foundation wall by applying PERMINATOR BUTYL TAPE around the base as well.
  3. Unroll the PERMINATOR underslab vapor barrier and spread it across the ground and up the foundation wall, sealing at the PERMINATOR BUTYL TAPE you’ve already applied.
  4. Install the TERMINATION BAR over the top of the PERMINATOR underslab vapor barrier, in line with the PERMINATOR BUTYL TAPE.
  5. Completely seal PERMINATOR underslab vapor barrier using PERMINATOR tape, to include all penetrations, all columns, and at the TERMINATION BAR.
  6. Adjust PERMINATOR underslab vapor barrier across the crawl space floor to ensure complete coverage and enough barrier to rest flush against all surfaces.
  7. Check local building codes for minimum overlap instructions. Some may call for at least six inches of overlap, while others may call for up to twelve inches of overlap. Overlap seams to at least the minimum requirements and seal with PERMINATOR tape.

Improving Crawl Space Cross Ventilation

As PERMINATOR is the industry-leading product for controlling vapor infiltration and also soil contaminants, such as radon, along with boasting a high puncture resistance, it is the perfect solution for crawl space moisture control. But you may want to consider combining it with additional water-proofing measures to maximize the reduction of moisture.

But what about water that may enter from runoff or leaking pipes?

Creating a waterproofing system in the crawl space area may best start with enclosing the area to prevent additional water entering from the outside. If the crawl space is completely enclosed, supplying air from the HVAC system can help to quickly evaporate any additional water that may enter the space. Installing a humidifier and exhausting air outside are also effective methods for keeping the crawlspace moisture free.

In the end, we all want to protect the commercial buildings we’re working on. And using PERMINATOR underslab vapor barrier to prevent ground moisture from entering a building through the crawl space is a great first step toward increased water damage protection.

Recommended Articles

We have some articles that I would like to recommend to the readers.

Foundation Repair And Maintenance

We have described here the type of foundations, what is a foundation inspection and what should be included in a good foundation inspection checklist. We can discover problems in the foundation to make us ask ourselves if it is safe to live in a house with foundation problems, and what entails a foundation repair. Not only the repair activity itself but how it affects our wallets.

I explain if the foundation repair is actually covered by homeowners insurance and the actual foundation repair cost. We disaggregated these foundation repair costs and determined, the cost per pier when footings or piers are the solutions for the settlement of a foundation.

To repair a foundation, the service provider might require an underpinning system using piers: push piers vs helical piers where helical piers are preferable for residential real estate objects, despite their costs. Also when you compare helical piers with concrete footings, we can determine that helical piers are more cost-efficient than concrete footings, in my opinion.

We have water in the crawlspace, which can be an issue for the whole foundation if the problem persists, and an additional difficulty when selling a house with water in the crawl space, as it can provide the prospective buyer with a lot of bargaining power, so what can we do: I explain what to do when the crawlspace is flooded or there are simply puddles of water always standing, thus I describe how to remove quickly the water in the crawlspace and how to prevent the problem for the future. So I discuss if it is normal to have water in the crawlspace after a heavy rain, and the importance to perform a crawlspace waterproofing thereafter, normally by installing a vapor barrier.

I describe how to improve the air quality in the crawlspace and to accomplish this, I am reluctant to use lime powder in this article, where I explain the pros and cons, as I would be using lime powder only to avoid the dangers of raw sewage under the house.

We discuss the sill plate replacement cost and how to avoid the outdoor sump pump freezing because it happened to me once.

There are always new methods for repairing foundations. One of them that we investigate here is the Powerbrace foundation repair method.

Animals can be a problem when they live near the foundation: In the following articles, we describe how to remove them and how to prevent them from digging and burrowing. The articles are about animals digging holes around the foundation or when they are burrowing below concrete, below a concrete slab, or between gaps in concrete footings, for example.

In regards to basements, I describe how to solve the hydrostatic pressure in the basement, which is a lateral pressure that is the main cause for having a basement wall that is bowing, or that can be caving in or buckling. While a slight inward curve for basement wall bowing is acceptable, after that degree, you have to address the issue and face sometimes relatively high basement wall repair costs.

I provide to you some reasons why we will need a certified specialist to deal with a risky sewage backup in the basement because bacteria survive a long time in a contaminated sewage network, and also we discuss how to deal with a basement drain backing up in general and what to do when it happens only when flushing the toilet, something that is not a DYI project at all.


I explain here the process of concrete lifting or concrete raising, which can be done through mudjacking or slabjacking. We recommend the latter, which injects polyurethane foam.


There are some interesting articles here, in this Framing category. I refer to sistering floor joists, as a methodology to reinforce existing floor joists with some emphasis on sistering 2x6 floor joists or sistering with 2x8 instead, and about the building code for sistering joists, for sistering rafters, and the code for notching floor joists.

Many of these problems have a consequence: sinking or sagging floors.

Water Heaters

About water heaters, we have a complete guide about water heater types and their installation requirements, about power vent water heaters, and venting in tankless devices, and I also explain in detail the difference between a mobile home water heater and a standard water heater. I also describe in detail how to remove the heating element without an element wrench using just a socket, and how to fix leaks.

We have a few reviews when a water heater falls into our hands, such as the Titan product portfolio, Navien lineup, the Titan N-160 reviews, the most praised by our readers, and the Rinnai R94LSi.

I study several water heater capacities and tested 20-gallon water heater units and a comparison between point of use and tankless water heaters.

We open a tankless water heater to show how does it look like inside a tankless water heater, and how to protect your water heater against the effects of hard water. I also explain the pros and cons of tankless water heaters because many people consider that tankless units are better than standard heaters and it is not always the case.

After the lifecycle of the water heater is over, I reveal to you different options to proceed with its disposal.


Just because they became popular and related to current news, I study how to identify aluminum wiring and once discovered, how to proceed with its remediation or retrofit.

Pest Control

I have a featured article where I compare Orkin vs Terminix pest control services.

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BY M. Kogan

Hello, I am Marcio. I am an architect and designer, alma mater is Mackenzie. Retired in theory, but an architect never retires completely. Along with architectural projects, I am a filmmaker and have completed some short documentaries. Filmmaking and design are my passions. In HomeQN I write about home decoration and foundations. The goal is to teach homeowners to DYI as much as possible, and when this is not possible, enable them through knowledge, to evaluate service quotations and choose the best service technicians.

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