Crawl Space Repair & Encapsulation

Cat Pee Smell In The Crawl Space

2018-03-20T08:07:00-05:00

The cause of the odor

So lately there has been a huge movement to confuse homeowners and professionals alike as to what actually causes this cat pee smell that about 5% of encapsulated crawl spaces get.

I don’t know why, but self identified “Experts” have blamed this cat pee smell on everything from reinforced plastic to the poor hygiene of a homeowners cat. We have seen online video’s from “nina” explaining how reinforced vapor barrier is “glued” together and when that glue gets wet it falls apart and then the string in the middle gets wet and smells like cat pee. Personally, I have never experienced making contact with any kind of string that smells like cat pee when it gets wet. This company’s ideas are clearly born from the purest form of ignorance, lacking the knowledge but claiming to be an expert anyway. After all they have some “kung fu plastic” they bought from the home improvement store to sell you, without the reinforcement that smells like cat pee of course.

The REAL Cause

In the videos we have posted online about this problem, we have identified the odor originates from the decomposition of plant material in the ground under the home. We also identified the elevated moisture levels in the ground, post encapsulation, plays a part in the cat pee smell complaint. We have continued to collect data on the conditions that surround this cat pee smell complaint, but have not been able to draw any conclusions....until now.

I don’t want to repeat the information that we have already posted so you can find it here- Crawl Space Odor.

Cat pee smells like ammonia, mostly because cat pee often has ammonia in it. Nearly everyone can identify what a claim of “cat pee smell” would smell like and ammonia is the common denominator. Ammonia is made up of Nitrogen and Hydrogen, NH3. When a plant breaks down in the soil, the bacteria decomposes the plant back into minerals other plants can use. If you look at the life cycle of Nitrogen you will see how ammonia NH3 (ammonium NH4) plays a role. (Info graphic courtesy of Wikipedia.org)

So what is the difference between ammonia and ammonium? The simple answer is pH. Higher pH levels in the soil support ammonia, cat pee smell and lower pH in the soil support a less toxic ammonium. Ammonia is one part nitrogen and 3 parts hydrogen, NH3. Ammonium is one part nitrogen and 4 parts hydrogen. Here is a great YouTube video explaining the relationship between ammonia and ammonium-

As you can see from this video, the relationship between the more toxic and cat pee smelling ammonia and the less toxic ammonium is a matter of pH balancing.

How To Prevent The Cat Pee Smell...

As a prevention to this bad cat pee smell showing up in your new encapsulated crawl space you will need to do one of two things; test and pH balance the soil as needed prior to encapsulating or install a soil gas mitigation system that will remove the ammonia smell (cat pee) from your crawl space once it arrives.

The pH scale is from 0-14 with 7 being neutral. Ammonia lives around 11 on the pH scale. The key is to get your soil pH as close to 7 as you can to prevent/eliminate this cat pee smell.

This cat pee smell does not come from polyester string, nor does it come from any of our products. The level of ammonia in the soil can permeate polyethylene and make the plastic smell as bad as the crawl space....but that is not the source

How To Install A Crawl Space Vapor Barrier

2015-07-15T22:43:00-05:00

DIY Crawl Space Encapsulation

Information on crawl space insulation can be found here- Crawl Space Insulation

Here is a straight forward step by step guide to installing a quality crawl space vapor barrier in your home. These are broad guidelines for you to follow that will apply to all crawl spaces. If you need additional guidance for more specific problems please contact us 877-379-7658. In the example below, we'll be using a 12 mil crawl space vapor barrier.

Step 1- Assess your crawl space

Before you do any work in your crawl space you should assess all areas, conditions and problems. This will help you later to know exactly what your up against.

Step 2- Lighting

You may not have thought that installing lighting in your crawl space would ever be a benefit, but if you want to solve your crawl space problems then proper lighting will be a useful aid in your efforts. Depending on the current conditions of your crawl space, I would suggest you first install temporary lighting and then wire in a permanent solution once all moisture and water problems are resolved. Here is a video about a crawl space work light you might find useful- Crawl Space Light

Step 3- Clean out and prep work

Remove everything that is not dirt or attached to the house. Most often crawl spaces are the dumping ground for building and remodeling debris, all of it must be removed to avoid problems with odor, mold and or punctures. No matter how strong the crawl space vapor barrier is, there is a possibility of punctures of sharp objects like crushed rocks, broken concrete and metal debris is not removed. IF it cannot be removed or is far to large or numerous to remove you can use a protective underlayment like the Felt550® to prevent damage to your investment.

Step 4- Measure your crawl space

You can guess at what you need to save time, but when it comes time to spend your money you will need to be accurate. To get a proper picture of what you will need for water control, a crawl space vapor barrier and a proper crawl space dehumidifier will be needed to start. You will need the following information.

the length of ALL your foundation walls
the height of ALL your foundation walls
the location of the lowest point in your crawl space
the location of your access to the crawl space
size of your access
do you have any water problems? have you ever seen ANY amount of water standing in the crawl space? are there stains on the foundation walls?
does your home have air conditioning?
does your crawl space currently have foundation vents to the outdoors?

Take this information and make a drawing of your crawl space. This drawing will aid in the planning and the execution of your crawl space project.

Step 5- Product selection

Resist the urge to make Step 5 the first step. Here's why; you should not make the crawl space fit the products, you should select the products that fix the crawl space. Certainly cost is a concern for most, but if you select a crawl space vapor barrier on price alone you will get what you pay for. Or worse, you will pay to much for a cheap product thinking it is better because a reseller calls an 8 mil thick vapor barrier a 20 Mil thick vapor barrier so their price looks CHEAP. Our recommendation assumes the reader: wants their work to last as long as possible, product quality is a concern and results are a must. Find the recommendation at this link- Vapor Barrier Selection From here it's time to get grizzly and fix that mess under your home. The final 5 installation steps are as follows...

DIY Crawl Space Liner Installation

Step 6- Tools

I am sure you already know, but I am going to say it anyway; it is so much easier, faster and cheaper to do ANY project when you have the right tools. Here are some tools to consider:

crawl space shovel
crawl space pick axe
crawl space knife
replacement blades
100' tape measure
hammer drill (not a drill with a "hammer" feature)
reciprocating saw (for plumbing work, cutting roots and buried debris)
screw drivers
hammer
wire staples
electrical cords w/GFI
Crawl Space Lights
respirator
organic mold cleaner
crawl space broom
small vacuum
Heavy workshop paper towels

Step 7- Foundation walls

This is the area that has the most fluctuation in install procedures from one company to another. I will tell you how we do it and then you will have it to compare to the many other variations. Some of the other procedures seem faster and better on paper, but do not pan out in practice. My example crawl space is going to be a rectangle, 30 feet wide 60 feet long and 4 feet 3 inches high and we will be installing 12 Mil GuardianLiner® In the procedure we recommend, you will install the walls first, but you must figure how your floors will lay before you can start. Facts:

In our example our crawl space is 30' wide.
The GuardianLiner® is 13'4" wide.
For best results, floor seam should overlap 10-12"
To cover the floor width we will need 2 pieces of GuardianLiner® with the width of 13'4" side by side
13'4 + 13'4 = 26'8" minus the 12" lap seam we can cover 25'8" of floor width with two pieces of GuardianLiner®
We have a 30' wide crawl space, we have 25'8" of crawl space vapor barrier to lay on the floor.
30' minus 25'8" leaves us 4' 4" short from covering the entire width of the floor.

Here is the reason we need to know the floor layout before we start cutting the walls- Now we know how short our floor piece is from reaching all the way across the crawl space, so we can make our wall pieces longer to cover the missing floor piece. We recommend hanging the wall pieces like wallpaper, in other words, the 13'4" width will go at the top and the bottom. This will give you many smaller pieces to handle rather than one large piece. The length of the wall section will equal the wall height (minus 3" termite inspection gap)+ floor overlap + whatever the floor piece is short.

In our example we are 5'4" short so I would tell you to split it equally on both side; you will need 2'8" + 12" floor lap on each side added to the wall piece. Our wall height is 4'3", minus 3" for the termite inspection gap and we are left with; 4' wall height+ 2'8" floor piece we are short + 12" floor lap= 7'8" wall lengths. Wall seams (between each wall piece) should be 4" to 6" over lap. This will not come out to an even number, but here is how you figure how many wall pieces you need.

Our crawl space is 30' wide and 60' long making our perimeter 180' around the crawl space. To figure the proper amount of crawl space vapor barrier to cut we will have to divid (13'4" minus 4" overlap) 13' by 180' which comes to 13.8 wall pieces. You will cut 14 wall sections 7'8" and since we left 4" for the wall over lap and there is extra you can make the wall laps wider than 4" (you have the extra material in the 14 pieces).

Make ALL your cuts outside and then bring them into the crawl space, it is much easier, faster and cleaner. Before you cut, consider this- If the floor is short by 2'8" on the sides you should make the length short by the same amount at both ends. Here's why, in a crawl space that is flat and the wall height is the same all around you can make all the wall pieces the same length (here 7'8") and not have to adjust at both ends with a shorter piece.

It does not matter what piece it comes from, the floor or the walls because you are sealing it with the seam tape. One other reason, the farther your tape seams are from the foundation wall the easier it is to tape. If you are taping 2'8" away from the foundation wall all the way around the crawl space it will be way easier for you and you can do a much better job sealing the seams. So in this example your floor pieces would be 54'6" long. That will leave a 2'8" gap on the ends that will match the 2'8" gap on the sides.

The other thing to consider before you cut is to cut both floor pieces first, then make the wall pieces from what is left. In our example, we want two floor pieces 54'6" long and each of them from one piece (no splices). This job will take three 13'4"x75' long rolls of GuardianLiner™ to complete, if done correctly. If you cut ALL the wall pieces first one of your floor halves will be in at least 2 pieces, not one. Here is how that happens, 14 wall sections 7'8" long comes to 108' of material.

You will get 9 wall pieces from one full roll and then you will need 5 wall pieces from another roll. Those 5 pieces will take 38'4" from the 75' roll. That roll is now 36'6" long and you need 54'6", so you will have to take the 20' from the other floor piece (75' long minus 54'6" = 20'4") and tape it to the end of the other floor piece to get the length right. It is not a big deal as far as function goes because you will tape the two together, but when it happens you will tell yourself you should have cut the floor pieces first.

Brush (not wire brush, just broom) the foundation wall at the top where you will be attaching the crawl space vapor barrier to remove loose dirt and spider webs. Install the Foundation Seal Tape™ along the perimeter of the foundation wall. You may need to use Poly Caulk if the foundation is very wet. Once the wall pieces are stuck to the Foundation Seal Tape and the floors have been taped to the walls you can install the Foundation Pins™. At the bottom of this article you will find videos for both Foundation Seal Tape™ and Foundation Pins™ installation.

Step 8- Floor

There is not much left to explain here. One advantage to splitting the floor width shortage of the crawl space vapor barrier to equal amounts on each side is your center seam will meet at your row of support columns so cutting around them will be much easier. Keep your vapor barrier pieces square to the crawl space and taking your shoes off will lighten the clean up work later. Here is a video on how to install a crawl space vapor barrier so you can see it in real time.

Step 9- Taping

The StIckE® Seam Tape is designed to work with the above mentioned crawl space vapor barriers and will not come loose when it comes in contact with water, this is very important because many "crawl space tapes" do just that. Take your time and remember to keep the crawl space vapor barrier square to the crawl space when you are taping

Step 10- Conditioning the air

A conditioned crawl space can be accomplished a few different ways, the important part is to DO IT. Conditioning a crawl space is THE reason the crawl space needed to be encapsulated, so don't skip this part to save money. Would you buy a pool and not fill it with water because it was not included in the price or it would make the cost of the pool less expensive if you left it out? Conditioning can be done with a quality crawl space dehumidifier or by using your existing air conditioning unit. Both options have their strengths. The best way to know which is best for your home is to get a moisture management plan for your crawl space. You can read more about a conditioned crawl space here- Conditioned Crawl Space

Install Videos

How to Install a Vapor Barrier with wall Insulation

2026-02-07T21:13:00-06:00

To get the most out of the SilverBack™ vapor barrier and foundation insulation, be sure to install both correctly. This diagram shows how to install them in your crawl space.

Click this link to learn more about crawl space insulation.

By installing the crawl space vapor barrier over the insulation you will prevent holes in the vapor barrier from securing the rigid foam to the wall. It goes without saying that the holes would not be a good thing.

The rigid foam will not absorb moisture. However, please be aware that spray foam is not the same as rigid foam. The spray on version will absorb moisture and that moisture will lower its R value.

Lean more about crawl space encapsulation and get familiar with everything you need. Crawl Space Repair has a number of different resources to help you. Every step of the process is important. Your DIY crawl space project is not as difficult as you think when you have the right resources.

What Crawl Space Vapor Barrier Thickness Do You Need?

2016-02-07T21:54:00-06:00

This is a very common question and it really depends on what is going to happen after you encapsulate your crawl space. Most people want nothing to do with the crawl space and are only going to go down there to do home maintenance. For those customers our selection of 12 Mil vapor barriers is perfect for them. It is an all around durable product that will allow for some light storage and superior moisture protection. All of our vapor barriers have a polyester reinforcement mesh. This makes the vapor barrier much stronger and confines any punctures.

The 8 Mil Pure Guardian® is a great product when there is limited head height or for use on the crawl space walls. Since the crawl space walls require very little durability from the vapor barrier it can be used to offset the cost of a thicker, stronger one. Even though this is the smallest Mil available by CrawlSpaceRepair.com it is still no wimp.

If the crawl space has a lot of rough ground, stones, heavy foot traffic or storage is desired then the 20 Mil SilverBack® is the one you want. It is the the strongest and has the most reinforcement in it. The 20 Mil has two layers of polyester reinforcement and three layers of virgin polyethylene.

The ground should be free from sharp objects with all of our crawl space vapor barriers to insure a long service life.

Protection for your floor

For those crawl spaces that have too many stones or starp objects and just can not be removed, take a look at our . The Felt550® was designed to protect your crawl space liner from your crawl space floor.

Your Crawl Space - Getting The Right Answers

2016-02-07T21:39:00-06:00

Chances are this is not the first article about crawl spaces you have read. There is a lot of articles on the web about how to fix a crawl space. Problem is, a good share of these articles are not written by someone that has actually done any research or even fixed a crawl space. They read an article about crawl spaces and then write their own version adding in what they have been told is the right way. This has caused the water to get really muddy. Some of this is due to the complexity of the subject.

There are many different factors that come into play when fixing a crawl space. What is right for one home might not be right for another. The location, age, size, symptoms and budget all affect the right answer. Some companies will try to sell everything and anything that has to do with a crawl space whether the home needs it or not. If the salesman doesn’t know what you need then selling you all of it should take care of the problem.

This is called ignorance, incompetence and/or sleazy sales practices. Some salesmen will even show a certificate that they were trained and are qualified to inspect a crawl space. Most likely, they were trained to sell the companies products. There is a big difference, but you will never know if you don’t ask good questions.

If you want to fix your crawl space, you need to encapsulate your crawl space. This involves sealing the crawl space off from the moisture outside. It's a term more homeowners are getting to know, but it's still relatively new.

Now, back to business. Soon, you get the "pitch."

So, how do you know when the good advice ends and the sales pitch starts? The only way you will be able to know the answer to this question is to educate yourself about crawl spaces, which is not as easy as it sounds. Even if you had a good idea what you want, by the time you research it on the internet you will most likely need to take a nap to clear your head.

One article will tell you to put in more foundation vents and the next article will say not to put in more vents but to use their “patented power vent” system at $500 or $1000 crazy each. Yet another article will tell you to close all of your foundation vents and another will say all of those other articles are messed up, you should open the vents in the summer and close them in the winter. So by this time the only thing you have learned is how much time it takes to get completely confused and frustrated.

The next subject that needs to be explored is the crawl space vapor barrier or “retarder”. During this search you find an article that says use 6 Mil plastic and another one says use 10 Mil barrier. Then there is a website that sells a “non woven material”, what the @#!# is that? But wait there’s more:)), another says 20 Mil and another says 12 Mil and yet another says 14 Mil. You'll also likely come across a bunch of content about the cost of vapor barriers too.

The underlying message in all these articles- Our vapor barrier is the best and will do the job the best and there is nothing like it on earth:)). Of course, a bit of an over exaggeration but it will certainly leave you with that impression. Then the final blow, “this is a job that should be left to the professionals”. What? As if!:))

The companies that make this statement are a bit pissed that no one wants to pay their high price. So the only way they can justify the cost is to tell the OWNER OF THE HOME your not qualified to fix your own crawl space. The only people that need to be “qualified” are the ones that don’t own the home, that is why they have to be qualified. Here is an example- to pull an electrical permit one need to be either: the owner of the home or a licensed electrician. In order to get a license they have to qualify. :))

Okay, I’m getting off topic, by this point you are either having fun with trying to get the answers to your questions or you’re at the kitchen table trying to gouge your eye out with a dirty fork:D. To make it worse, IF you are up to continuing your search you will also find companies that try to gain credibility with you by using a blog. The blog looks full and has many entries and comments. It seems these guys are the ones that others look to. But wait! The entries (and comments) were copied and pasted from other websites like Yahoo Answers.

The company that sells the “non woven material” actually went out and started 6 or 7 blogs and then searched the internet for questions and answers about crawl spaces. He apparently found a gold mine at Yahoo Answers and felt who would even know. After he copied and pasted the other site’s information as his own he then proceeded to link these blogs back to his site that sells his “non woven material”. That is like faking testimonials|-|. You may have to scroll down on the poser’s blog to find the bogus entries. This is pretty easy to discover, and I recommend finding out if the owner of a blog really knows what he is talking about before you follow the advice. Here is a way to validate the blog:

1. Copy a full sentence from the blog entry
2. Paste in the search bar, Yahoo works better because it will show all entries that match exactly, Google will only show the entry it thinks is the right one and take the other out of the search results
3. Look through all search results, I highly doubt Yahoo Answers would steal from a small blog

My advice is to trust your gut, you will know the right answer when you see (hear) it. Keep looking and don’t rush into any sales pitches. If you feel like you were dazzled then you probably were. The flashier the presentation the more it is meant to distract you. The honest guys will want to help you, without pressure. Remember, if you hear – “Besides the price (cost) is there any reason you wouldn’t ……today?” you’re being pitched, be careful.

Crawl Space Moisture Problems- An Email From Brian

2016-02-07T21:26:00-06:00

Matt,

I wanted to take this opportunity to thank you so much for your website. It is extremely informative and helpful to the DIYer like myself–I’ve read every single page you have on your site. I have a fairly serious moisture problem in my crawlspace at my home in Virginia Beach. My washer machine plumbing had a small leak that I didn’t notice for many months. This has led to some pretty nasty mold growth under the crawlspace. I crawled down to check it last week and while I’m fairly certain it's structurally sound the things growing down there are horrid.

I also noticed while I was down there that I have had significant pooling of rain/ground water near the front of my house. I had every intention of buying your products and doing the vapor barrier/sump/dehumidifier install myself, however after looking at my situation closely, I don’t think you could pay me enough to do it. I only have about 18 inches of height and 24 individual pilings that would need wrapped. Not gonna happen. So I called a well respected local company, JES basement systems. All they do is crawlspaces and basements.

They use the Clean Space line of products mentioned in some of the emails you posted on your website. I have a little over 1200 sq ft of crawspace (their estimate, which includes the walls and pilings), they will also install the 57 linear feet of drain piping, connected to the smart sump and also includes the sani dry dehumidifier. Total for the Cleanspace install. with removal of some debris, was $5k, drain piping and sump was another $2k or so, the Everseal crawspace door was $400, then another $1500 for the crawlspace dehumidifier. All total it was just over $9k but they gave me a military discount which reduced it to $8510. I drank the Kool-ade and signed the contract to have them do it. It comes with a transferrable 25yr warranty on the cleanspace–maybe a gimmick, but this is a well respected local company and I believe they will stand by it.

I do have a couple of concerns, however, that I hope you can shed some light on. I asked them about cleaning the mold and they said once the humidity drops (mine is currently around 75%) to below 50%, the mold will die. This is fine, but can the dead spores still “infect” my living space? Does your company do anything to kill/remove the mold growth prior to install of the vapor barrier?

Second, once the vapor barrier is installed, it seems to me that the concrete blocks of the perimeteter wall and pilings would be subject to increased moisture levels. What is the long term effect on them? I may have a much improved crawl space, but if my house collapses, its all moot. Is this a valid concern or am I worrying about nothing?

Thank You,

Brian *****

Response-

Brian,

Thanks for the email! And thanks for the compliment, we work very hard to make good information available.

I want to get your questions answered first. The mold will not just die if the humidity goes below 50%, it will go dormant waiting for the moisture to return. The health effects, whatever they are with the type of mold you have, is still there and yes it will still infect your home. This is going to need to be dealt with.

Yes, the foundation walls will be subject to increased moisture levels, but the concrete is suited to handle that environment. Think about the footing of the home, it is buried in the ground with moisture on nearly all sides and piers that hold up bridges over rivers are under water. The foundation will not be harmed while exposed to the moisture. This said, it is important that there is no “moving” water passing through the foundation. Did the basement systems dealer give an outside water management plan (grade, gutters etc.)? If they did then make sure you put that in motion before they install the Clean Space.

I have heard about JES, mostly that they are expensive, and I have looked them up on the BBB. They have only one complaint; a warranty issue oddly enough. I respect that you are comfortable with them and that is important. I do however, have a concern with some of the things they are selling you. You said you have 1200 sq ft but they are only putting in 57 feet of drain tile; why are they not going all the way around the foundation? Other basement systems dealers do not charge for up to 100' of drain tile when you buy the cleanspace and a sump pump together.

The smart pump is a “mini basin” (here is a pic and sales pitch -) sump pump system. It comes with a Zoeller M-53 pump which is very good, we use the same one, but it is put into a shortened basin which will cause the sump motor to short cycle. In other words there will not be enough water in the basin for the pump to run a full pumping cycle. This shortens the life of the pump because of the quick on and quick off pumping. They probably did not tell you (it will be in your warranty after the job is done and paid for) that the pump motor is not covered by them and has a 1 yr manufacture warranty against manufactures defects, not cycle burn out. This is a case of you getting what is easy for them, meaning the height of the crawl space is too small to easily put in a regular basin (which we do on every job), instead of earning their $2000.

My point is, their warranty will only be good provided the pump has power and is working properly. If the crawl space floods and it is because the pump failed then it is not covered by warranty. Sneaky huh? Another concern is when the pump fails the drain in the top of the smart pump will allow water to freely enter the crawl space. The basement systems dealers promote this drain as a good thing, but it works both ways. The ping pong ball that sits over the opening allows water to enter the basin by floating away from the actual opening. This design will also allow water to past back up into the crawl if and when the pump fails. Besides this being an obvious problem, the water will bring with it dirt and mud from under the Clean Space making the clean up a much larger job.

You also stated that the crawl is only 18? high, their santa-dri dehumidifier is 19? high-( Crawl Space Dehumidifier Comparison ) and it concerns me that it may not fit and if they can get it to fit; will it be located properly to do the an effective job?

Brian, I am not trying to talk you out of working with this company, I just think you should know some problems you will be faced with after you pay your $8500. It is possible that when you call them they will come out with no problem and fix the issue but for $8500 it should work without issue and I think that is what you are expecting, as you should.

I am glad to hear you received a discount because you are/were in the military. That shows great respect which you have rightly earned. I think you should also know, I talk to people all over the country and it seems very common for the basement systems dealers to give discounts. Some of the more common are: senior, single parent, first time home buyer, and “I like you, let me call my manager”. If you would have held out they would have come down even more, that is the game.

If you are still within your right to cancel the contract I would suggest you do that and renegotiate the scope of work for the price you are paying. Get a full perimeter drain system with a full size sump basin (they sell those too), get exact details on where the dehumidifier will be located and how it will drain ( it needs to be located in the center of the crawl). Ask to see the warranty that you will receive and get the details that concern you changed and written on a separate “non-service agreement” form. Note that on the back of your contract it will state something to the effect – “There is no warranty of merchantability or warranty that contractor’s services will be fit for a particular purpose or any other warranty under this service contract other than expressly stated in the separated, written warranty”. This means, if you ask or they offer to hand write on the contract any modifications to the “separate warranty” it will be void. They (the franchise) has spent a lot of time making sure they have the upper hand in the contract, this is your chance (if not to late) to make your own modifications to insure you get what the salesmen promised.

I hope I have not dashed your hopes of a successful transaction. I do, however, want you to get what you expect and get your money’s worth.

Let me know if there is anything else I can do to help,

Crawl Space Moisture, an email from a customer

2016-02-07T20:56:00-06:00

Hi,

My crawl space is moist, i.e., the air is damp and the foundation walls show signs of wetness. A mold inspector has not found mold and the subfloor is dry. I am planning to dry out the crawl space and I have a few questions regarding your product and the various approaches that I’ve read about:
1. I’ve come to your site via ‘Ask the Builder’ where you or one of your colleagues pointed to the Crawl Space Vapor Barrier product. (Very nice site, btw.) In the article, Tim Carter (author of ‘Ask the Builder’ column) referred to high performance polyethylene. Can you tell me what the advantage of the Crawl Space Vapor Barrier over the high performance polyethylene is? I’m not planning to use the crawl space for storage.
2. Based on what I read, the best practice indicates that one should close the crawl space vents and to seal the crawl space. But given that moisture will still be underneath the vapor barrier, will this not lead to wet foundation walls and wet studs underneath the vapor barrier?
3. I’ve read about two alternative approaches to dry out the crawl space:
a)use a crawl space dehumidifier
b) open up a HVAC duct and an air return to dry and warm the crawl space through conditioned air.
– Is option (b) the cheaper solution that is recommended for less moist crawl spaces. Is option (a) recommended for severe cases? We live in Maryland (West of DC), so it gets humid in the Summer, but it’s not as wet as in the Eastern Shore.
– Does option (b) require insulation of the foundation walls, while option
(a) does not?

Any help would be greatly appreciated.

Many thanks,

****** (customer asked to remove his name)

Response-

Thanks for the email!

1.The big difference in vapor barriers is whether it is made of virgin polyethylene resin and if it has a polyester reinforcement, which all of ours do. Our vapor barriers are considered high performance. I believe the confusion is in the lingo.

2.It is true that moisture will be trapped under the vapor barrier, that is what we want. Currently the moisture is not trapped so it is allowed into the crawl space. The moisture against the foundation walls will not damage the concrete. Think of it this way, the outside of the block is (most of the
time) under grade and exposed to a much harsher environment. If you have wood studs in the crawl space they should never be under the barrier. All wood, including the sill plate should be left exposed to the crawl space.

3. I am assuming you are asking about after the crawl space is sealed up. I personally see a greater advantage in adding the conditioned air to the crawl space over a dehumidifier, provided you live in the home year round.

If this is a vacation home the a dehumidifier is probably better suited to care for the crawl space when you are gone. Of the two the cost effective option is the conditioned air. Professionally, it is my opinion that you will need to add a mechanical means of air flow in the crawl space once you close the vents. However, personally I recommend sealing the crawl space and then monitor the humidity and temperature before making a final decision on what it best for you home concerning air flow in the crawl space.

There are remote hydrometers you can purchase to collect this information without getting into the crawl space every day. The subject of crawl space insulation can be quit complicate and in my opinion it will take a conversation between both of us in order for me to best guide you. As a set answer I would direct you to your local building code or energy code for guidance. I say this because without all the information I do not what to steer you in the wrong direction.

I hope this helps!

Crawl Space Drains- What if I have a leak?

2016-02-07T20:48:00-06:00

What if I have a leak from a pipe after I have my crawl space encapsulated? I will have a swimming pool under my house, should I have some kind of drain installed in the vapor barrier?

This question usually arises after meeting with a franchise company that sells a drain for their vapor barrier system. The product pitch is designed to settle a fear of what if my crawl space gets water in it from a frozen pipe or broken water line. The drain is designed with a ping pong ball under a drain cover that will float when water enters the drain. Once the water is gone the ball then returns to cover the opening leaving the homeowner with the understanding that they will have to do nothing for clean up. Pretty ingenious if you only look at the pro’s of the design.

So lets take a look at the con’s to better determine if a drain in the vapor barrier is a good idea. The same mechanism that allows water to enter the drain, the ping pong ball, will also allow the water to enter your crawl space from under the vapor barrier. If the power goes out and your sump pump is temporary not pumping water and the water backs up, then the ping pong ball will float and allow water to get on the barrier. In this scenario the water will be dirty allowing mud to settle and making the clean up a much bigger job.

Another major flaw in this design is what if the drain is on the west end of the crawl space and you have a leak at the east end? Unless the drains are placed throughout the crawl space under each bath, kitchen and laundry it is not likely the water wouldn’t go into the drain in the first place. In order to fix this ‘what if’ it causes more compromises in the barrier and in many different locations.

Beyond these two problems, if the crawl space is sealed properly the threat of frozen water lines is very unlikely. Frozen water lines is a condition of an sump pump system not a closed or conditioned one. Which is what you would be paying for, so why the back up plan? Moreover, the chances of a power outage happening during a heavy rain storm is far more likely. This situation causes the threat of water entering the crawl space, while the sump pump system is down, and then making the chances of water entering through the drain a real problem. This problem is probably one of the reasons you were talking to them in the first place. In my opinion, the sales pitch diverts the focus of the real threat to a “what if” situation to build confidence in a product line. Know this, sales pitches are designed to really accomplish one thing- psychological dominance. To present, convince and close the sale. The drain is not the focus of the pitch it is an example of setting a fear and presenting a solution to build confidence in the system.

So what do you do if a pipe breaks or the washer over flows? I say handle it “IF” it happens. By cutting a small slice in your crawl space vapor barrier to allow the majority of water to drain into the drain system or under the barrier. By doing it this way you can drain the water where the water is and not have to push it to a fixed drain. Then once the water is gone and you have mopped up the last puddle, tape the slice with the same tape used to seal your lap seams. This gets you as good as new and the option to simply remove the tape “IF” it happens again. This process handles any real problems not just the threat and it does not cause any new ones.

How to Install A Crawl Space Drain System

2015-04-23T13:08:00-05:00

Crawl Space Drain Systems

Dig the trench 5-6" deep or deep enough to keep the drain pipe level and below the crawl space soil line

Do not put dirt on top of the drain tile, leave it open or covered with pea stone
Do not dig the trench at a slope to the basin, this will cause erosion and your pipe will be to deep for the basin
You should bury the entire drain pipe in pea stone if:
1. it does not have a “sock” on the pipe.
2. the soil is mostly clay.
3. you are concerned about clogging
If the drain pipe does have a sock (which it should for this application) then stone is not necessary on all of the pipe. This is because the sock does part of stones job by filtering soil.

*This advice does not apply to every job, everywhere. Please check with your local building codes and local experts for final design.

How To Close Crawl Space Foundation Vents

2015-03-25T15:40:00-05:00

How to Install Foundation Pins™ - Video Walkthrough

2015-02-07T15:30:00-06:00

Installing the Foundation Pins™ may seem like it is too hard or unnecessary, but I assure you it is needed in order for your investment to last the many years you are expecting it to. Caulks, adhesives and just plain goop will not hold anyones liner to the wall for long without a mechanical fastener. If it could be done without any permanent fasteners, then all of the professional installation crews out there would be doing it without them, but they are not.

The installation is as simple as drilling a small 1/4" hole through the crawl space liner at the Foundation Seal Tape™ and insert the Foundation Pin™. The video illustrates the process.

Installation Of The Foundation Seal Tape™ - Video Walkthrough

2014-10-16T14:39:00-05:00

Like any tape you want to make sure the surface is clean and dry. A small hand broom works well and will get the job done. A steel wire brush is too coarse and will cause unneeded surface dust. The only time this tape won’t work is when the foundation block is either damp or dirty. If it is to damp to stick you can use a polyurethane caulk to seal the crawl space liner to the foundation after the foundation pins are installed.

When used properly this tape will save you hours and give you a permanent seal.