Waterproof Your Basement for LOW COST.

Introduction: Waterproof Your Basement for LOW COST.

About: I like building things. I like to experiment with alternative methods of heating and cooling houses.

How would you like to waterproof your basement or fix a leaky cracked foundation for very little money... and only a few days of work? This system places FIVE barriers against leakage!   I did this to a house i lived in 30 years ago.  The basement stayed DRY the 19 years I lived there.. AND this only costed less than $100 dollars per wall.  Only 2 of my walls had leaks (I fixed).  This method stops water OUTSIDE the foundation, which is preferable.  A friend recently asked me if I knew anything about fixing a cracked basement wall and leak?  I printed it out for her... and decided to make an INSTRUCTABLE for others who may need the information.   LEGAL: NOTICE:  These instructions are no guarantee you will fix your problem. Whatever you do to YOUR house is your decision and your responsibility solely.  (but this worked for me, and might help you too). Digging the trench is the most difficult step... but not as difficult as we imagined before starting.  It took us about a day and a half to accomplish digging up ONE side of the house.  A couple days to do all the chipping, tarpainting, and placing the plastic sheet.  then one day to fill trench back in.

Step 1: Diagram of Leaky Wall and Overview of Project

The diagram shows the simple solution to the leaky problem.  Water is SUPPOSED to flow down to the FRENCH DRAIN. (pictured at bottom of diagram).   Cracks often occur below windows and usually go all the way down to the concrete floor.   After digging down to the bottom of the wall... about 3ft deep.... you may hit a layer of GRAVEL.  That is the french drain.  Dont dig up the gravel.
The main part of this system is the plastic sheet which is TARRED up against the wall.  Plastic sheets will last many years under the ground.  Some environmentalists say it may last 100 years.  The sun does not shine on it and the wind does not blow on it... so it should last a LONG time.  This repair is also COMPLETELY HIDDEN  and not visible because it is under ground. so don't worry about how it is going to LOOK !


Here is what you will need to accomplish this project:

1.  Shovels, picks, for digging the 3ft deep trench
2. Large wire-brush for cleaning dirt off of outside wall
3.  Bucket of water & rags for final cleaning of wall
4.  Air-hammer (handheld) and air compressor
5.  Concrete crack patch or expansion cement
6.  Long roll of plastic sheet. about length of wall and 6ft tall  thick not thin plastic.
7.  Gallons of DRY-LOCK product (optional and expensive). I didn't use it.
8.  5 gallon bucket of driveway tar.
9.  Paint roller & brushes (cheap or old junk ones) for rolling tar onto wall
10.  A couple good friends who will help you is recommended.


Decide whether you are going to repair the whole wall as a precaution against all future cracks or just dig up around the window that has the leaky crack.  Then get started:

1.  Finish digging ALL THE WAY down to the INSIDE FLOOR level.  My house was only about a three foot deep dig.  so we decided to just go all the way across the whole wall and do the whole wall. If you dig down and hit a layer of GRAVEL... stop digging. You have reached the FRENCH DRAIN.  Most houses have a drainage pipe around the foundation which is surrounded by large gravel.  Water is supposed to go into this area below the basemet floor and drain away.  You dont need to dig it up.

2.  Use a wire-brush to scrape all the dry dirt off the entire wall.  Then clean wal with water soaked rags.  This is to assure the tar applied later will STICK to the WALL and not to a dirt layer. 

3.  Chip (air-hammer)  the leaking CRACK into a LARGER (wider) crack as shown in the photo.  This is done because it is difficult to get any caulk into the THIN NARROW crack.  Also, the wider crack will ADHERE better to the caulk or expansion cement we apply to fix the crack.  When done chipping the crack wider, fill with whatever patch you have chosen. 

OPTIONAL... paint  outer wall with DRY-LOCK product.  I didn't do this to my wall, because it was expensive and I trusted the tar and plastic would do the job.  After it dries.. go to step 4.

4.  Put on some junk clothes because they may get tar-stained.  Use your paint roller to roll the driveway tar across the wall. BE CAREFULL to only cover the wall where it will NOT BE SEEN after the dirt is replaced.  Plan on adding extra dirt if yours does NOT slope away from the house. It is important that rainwater flow AWAY from the house and not sit in a PUDDLE near the foundation,
"Paint" the wall with the tar. Use handbrush where the roller can't go. 

5.  Unroll your long plastic sheeting and place it up against the wall.  A few feet of EXTRA plastic sheet will extend above the foundation. Thats OK... but dont cut it off.  For now, just use some tape and tape it UP to the upper wall and out of the way so you can finish filling the ditch.

6.  Start tossing the dirt back into the ditch. Toss GENTLY so as to NOT tear the plastic sheet.  Soak the dirt with water hose a little as you go. This will help the dirt to settle.  Dont over water.  Fill the trench about 75 % full.  If possible, try to SLOPE the dirt in such a way that dirt is HIGHER near the house and LOWER away from the house. Then lay the plastic down  on top of the sloped dirt.  This further encourages water to go AWAY from the foundation.

7.  Finish filling in the trench 100 %. add MORE DIRT if you dont have a SLOPING grade away from your foundation.  At this point, you are done fixing the LEAK... but you may choose to go INSIDE the house and use expansion cement and patch the cracked foundation INSIDE.  This is mostly for COSMETIC reasons because the wall will not leak now. 

Step 4: Five Barriers to Stop the Water Leaks !!!

This system places FIVE barriers against future leaks.  Two of the barriers are FLEXIBLE. This flexible barrier is insurance in case the wall cracks again in the FUTURE.  Here are the five barriers listed;

    1... Sloping above ground dirt guides water AWAY from house
    2... Plastic below ground slopes away from house further guiding water away. 
     3... Plastic barrier up against concrete wall and "glued" to wall using tar. (flexible)
    4... Tar layer across the wall is another barrier.    (flexible)
     5.... Cracked wall is chipped wider and filled with patch
     6.... optional 6th barrier is DRY-LOCK painted on before tar is applied.

                             FINAL  NOTES :

This wall will probably never leak again in your lifetime.  If your leaking wall is on the side of house that has a concrete driveway or other obstruction.... this idea will not work unless you are willing to have the concrete layer removed so you can access it.   Be sure to do easy fixes FIRST... such as rain gutters do not dump into big puddles against your wall.  I want to appologize for not having MORE pictures of the actual project.  I only had ONE picture from the job from so many years ago.

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    3 Discussions


    8 years ago on Introduction

    Yup. It's an awful way to die. Even a fairly sloped wall can collapse.


    8 years ago on Step 3

    Please be VERY careful working in any kind of trench. We regularly lose people when the trench collapses. When the pros do it, they use HEAVY reinforcement.


    Reply 8 years ago on Introduction

    I was about to say yeah right but just searched for the terms " man dies digging trench" yeah, 770,000 results.... Wow Thank you for the warning!