by Carey, James
To repair large gaps (1/4 inch or greater) in concrete (such as those between a concrete slab and foundation wall) that are not structural in nature and don’t require advice from an engineer, use a latex caulk that contains silicone or a polyurethane caulk. You pump these products into the joint with a caulking gun; the caulking products remain pliable to allow for ongoing expansion and contraction. (Because most of these caulking products are self-leveling, no troweling is required.) Be sure to lightly spray the patch with water twice a day for a week to help it cure and prevent cracking.
Tuck-pointing brick and block foundations
Before the 1930s, bricks were used extensively to construct foundations. Today, however, if a foundation doesn’t consist of solid concrete, it’s probably constructed of concrete block. In either case, brick and block have one thing in common: They’re both joined together using mortar, a combination of sand and cement.
Unfortunately, over time, mortar tends to deteriorate. Not only are cracked and deteriorating mortar joints unsightly, but they also diminish the integrity of the surface and can allow water to get behind the brick or block and cause major damage. You can avoid these problems by tuck-pointing the brick or block foundation, which means removing and replacing cracked or missing mortar.
If the area is manageable, any do-it-yourselfer can easily perform the task by following these steps (shown in Figure 4-5). Note: If the cracked or deteriorating mortar is extensive — an entire foundation, wall, or wainscot — leave the tuck-pointing to professionals.
Figure 4-5: Tuck-pointing mortar joints.
1. Chip away cracked and loose mortar using a slim, cold chisel and a hammer; remove the existing material to a depth of approximately 1/2 inch.
Be sure to wear safety goggles to avoid catching a piece of flying mortar in the eye. Use the cold chisel slowly and carefully, to avoid damaging the surrounding brick. Clean up all the loose material and dust using a brush after you finish chiseling.
2. Prepare your mortar and allow the mix to set for about five minutes.
You can buy mortar premixed, or you can create your own batch using one part masonry cement and three parts fine sand. In either case, add enough water to create a paste — about the consistency of oatmeal. It’s best to keep the mix a touch on the dry side. If it’s too runny, it’ll be weak and will run down the wall, making it difficult to apply.
3. Brush the joints with fresh water.
Doing so removes any remaining dust and prevents the existing mortar from drawing all the moisture out of the new mortar. Otherwise, the mortar can be difficult to apply and will most likely crack.
4. Apply the mortar using a pie-shaped trowel called a pointing trowel.
Force the mortar into the vertical joints first, and remove the excess (to align with the existing adjacent mortar) using a brick jointer. The brick jointer helps create a smooth and uniform finish. After all the vertical joints are filled in, tackle the horizontal ones.
Avoid applying mortar in extreme weather conditions because the mortar won’t properly set up.
5. A week or two later, after the mortar has had the opportunity to set up, apply a coat of high-quality acrylic or silicone masonry sealer to the entire surface (brick, block, and mortar).
The sealer prevents water damage, which is especially important if you live in an area that gets particularly cold. Unsealed brick, block, and mortar absorb water that freezes in cold weather. The water turns to ice and causes the material to expand and crack. Periodic sealing prevents this situation from occurring.
Preventing moisture under your home
If you see efflorescence (see the earlier section “Is there a fungus among us? Dealing with efflorescence”) on your basement walls and/or crawlspace and your crawlspace is perpetually damp and mildewy, you have a moisture problem.
What’s a little water under the house going to hurt, you ask? Lots! Aside from turning a trip into the crawlspace into a mud-wrestling match or your basement into a sauna, excess moisture can lead to a glut of problems such as repulsive odors, rotted framing, structural pests, foundation movement, efflorescence, and allergy-irritating mold. We can’t stress enough the importance of doing everything you can to keep excess moisture out from this area of your home.
Rooting out the cause of the moisture
A musty or pungent odor usually accompanies efflorescence and excessive moisture. Accordingly, a good sniffer proves invaluable in investigating the problem. Here are common causes of moisture:
Leaks in water and sewer lines under the home: A failing plumbing fitting or corroded pipe is often the culprit. Fitting a replacement or installing a repair sleeve around the damaged section of pipe almost always does the trick. (See Chapter 8 for information on how to perform these maintenance tasks.)
A leaking toilet, tub, or valve located in the walls above: Although a leaking toilet is often visible from above, most leaks must be searched out from below the floor. When it comes to finding the cause of a damp basement or crawlspace, leave no stone unturned.
Overwatering planters surrounding the house: Adjusting watering time, watering less often, installing an automatic timer, and adjusting sprinkler heads are the simplest means of solving this problem. Better yet, for planters next to the house, convert the traditional sprinkler system to a drip irrigation system. Doing so not only helps dry things out under the house, but also makes for a healthier garden and conserves water as well.
Poor or nonexistent floor insulation: Poor floor insulation can be another contributing factor to heightened condensation or dampness in a crawlspace or basement. (See Chapter 6 for more information on insulation and the importance it plays.)
Diverting water from the foundation
Keeping water out of the crawlspace or basement is critically important. You can acquire the necessary protection in several ways.
Making the grade
Be sure that the soil around your home slopes away from the foundation. The slope helps to divert most irrigation and rainwater away from the structure.
The earth within 30 inches of the foundation should slope down and away at a rate of 1/10 of an inch per foot. We think that 1/4 inch per foot is better.
If you’re having a difficult time determining the slope, use a measuring tape and a level. Rest one end of the level on the soil against the foundation and point the opposite end away in the direction that the ground should slope. With the bubble centered between the level lines, use the measuring tape to measure the distance between the bottom of the level and the top of the soil. For example, if you’re using a 3-foot level and you’re establishing a grade of 1/4 inch per foot, the distance between the level and the soil should be at least 3/4 inch.
To grade the soil around your home, you need a pick, a shovel, a steel rake, and a strong back. You also need a homemade tamp that consists of a block of wood attached to a wood post that serves as a handle. Use the pick to loosen the soil and to break large clumps into smaller, more manageable soil that you can grade with the steel rake. Rocks and large clumps should be removed and replaced with clean fill dirt that can be well tamped. After you complete your grading work, use a garden hose to wet down the area to further compact the soil. Wetting down the area also gives you an opportunity to test how the soil drains.
Build up your grading with well-tamped dirt and not loose topsoil, which easily erodes.
Paths and patios should slope away from the foundation, too. A patio or path that slopes toward the home discharges water into the basement or crawlspace, a condition that breeds foundation problems and structural rot. Unfortunately, the only sure way to correct this problem is to remove and replace the patio or path, and that can get really pricey.
Using gutters
Contrary to what you may think, rain gutters are more than a decorative ele-ment for the roofline of a home. Their primary purpose is to capture the tremendous amount of rainfall that runs off the average roof. Without gutters, rainwater collects at the foundation
and, consequently, ends up in the crawlspace or basement. So, if you don’t have gutters, install them. And if you do have gutters, keep them clean. (See Chapter 5 for more information on cleaning gutters.)
Make sure that your gutters and downspouts direct water a safe distance away from the house. Even worse than not having gutters and downspouts is having downspouts that jettison water directly onto the foundation. We recommend piping the water 20 feet away from the foundation. You can use a length of rigid or flexible plastic drainpipe (without perforations) to carry water away from the downspout outlet to a safe location. Better yet, to avoid an eyesore and a potential trip hazard, bury the drainpipes below the ground.
Giving the problem some air: Automatic foundation vents
Ventilation is another effective means of controlling moisture in a crawlspace or basement. You can use either passive or active ventilation:
Passive ventilation doesn’t use mechanical equipment. Foundation vents (metal screens or louvers) and operable daylight windows for basements are the best sources of passive ventilation.
Active ventilation involves mechanical equipment, such as an exhaust fan.
Passive ventilation should always be your first choice because it allows nature to be your workhorse and doesn’t necessitate the use of energy to drive the mechanical device. You save on your utility bill and help the environment by not relying on fossil fuels.
If you use passive ventilation, you must keep the vents clean to allow maximum airflow. You may need to thin nearby shrubbery, vines, and ground cover from time to time. If vents are clear and moisture is still a problem, you may be able to add additional vents. Because adding vents can affect the aesthetic and structural elements of the home, consult a qualified engineer for this project.
All the passive ventilation in the world may not be enough to dry out some problem basements. In this case, install an active source of ventilation, such as an exhaust fan. Installing an exhaust fan requires some minor carpentry and an electrical source. (See Chapter 10 for more information on ventilation.) Never hesitate to use active ventilation when your crawlspace or basement needs it.
Installing a vapor barrier: Crawlspace finishing systems
Excessive dampness in a crawlspace or basement can condense, causing floor framing to become damp and covered with fungus, efflorescence, and rot. To avoid this damage to the floor framing, you can install a vapor barrier consisting of one or more layers of sheet plastic (6-mil Visqueen) on top of the soil in the crawlspace or basement (see Figure 4-6).
Figure 4-6: Installing a vapor barrier.
If you’d rather have someone else take on this less-than-desirable-job, an entirely new industry has cropped up consisting of firms that specialize in crawlspace finishing systems. The average system consists of a sheet plastic that is about ten times thicker than the DIY 6-mil stuff. They also use industrial-strength tape, caulking on the walls, and an assortment of other tools and techniques that will make your crawlspace almost livable. Check in your local Yellow Pages or search online for “crawlspace finishing systems.”
Lap the plastic a minimum of 6 inches and seal the seams with duct tape. Cut around piers and along the inside edges of the foundation. In severe cases, you can run the plastic up the sides of piers and the foundation and secure it with duct tape or anchor it with a line of soil at the perimeter.
Just because you installed a vapor barrier doesn’t mean that your work under the house is done. With the plastic in place, you have a nice, dry surface on which to work to remove efflorescence or mold that has propagated on wood framing. Wearing safety goggles, use a wire brush and a putty knife or paint scraper to clean the affected areas. (Also, see “Is there a fungus among us? Dealing with efflorescence,” earlier in this chapter.)
As you remove efflorescence or mold, have a blunt tool handy, such as a flathead screwdriver, to test for evidence of rot. If you can insert the blade of the screwdriver into the wood fibers using moderate pressure, it’s time to call in a pest-control specialist to make an inspection and suggest needed repairs.
Wood framing that was previously damp but not severely damaged should be treated with a wood preservative that contains a pesticide such as copper or zinc naphthenate. This wood preservative is a liquid that you can brush on with a disposable paintbrush.
Use extreme caution when working with wood preservatives that contain pesticides. They can be hazardous to your health — not to mention the fact that they have a fierce odor for the first week or so. Follow the manufacturer’s instructions on the label to the letter.
Saying oui to a French drain
If the advice we give in the previous sections doesn’t help, and you’re still faced with a crawlspace or basement that looks like the La Brea Tar Pits, it’s time to call in a soils engineer to determine whether the condition requires the installation of a French drain, an elaborate drainage system that consists of a trench filled with rocks and a perforated drainage pipe. The rock-filled trench, acting like a drainage ditch, collects water that easily travels through the rock and down to the pipe. The holes in the bottom of the pipe allow it to collect the water and direct to a point where it can be safely discharged.
If you already have a French drain, it needs maintenance. Clean the inside of the pipe once a year using a pressure cleaner, a high-powered water blaster with a hose and nozzle for specific use within drainpipes; you can rent this equipment from a tool-rental company. If you don’t want to clean the French drain yourself, have a plumbing contractor or a sewer- and drain-cleaning service do the job for you.
Tackling spalling and disintegration
Spalling, or chipping, occurs when water gets into the foundation, freezes, expands, and breaks away small pieces of the surface. Disintegration occurs for the same reason or can be due to attack by salt. Poorly mixed concrete is another cause of both of these conditions.
You can repair both spalling and disintegration with a latex patching compound. Prevent spalling from happening in the future by applying a protective sealant, which helps to prevent salt air, water, and snow melt from attacking the foundation surface.
Not settling for settling
When the earth moves, so does the foundation — and so will the entire home. The result can be as simple as a squeaking floor, or it can cause major cracking in the foundation and every other part of the home. Doors and windows can stick, glass in windows can break, and even sinks can chip.
Minimize damage by contacting a structural engineer as soon as you notice one of these symptoms. Repairs of this nature are always expensive, but if left unchecked, they can end up costing ten times more. With proper intervention, you may be able to slow and even prevent future shifting.
Keeping Your Basement Dry
Finished or not, one place you don’t want water is in your basement. Besides yucky dampness, smelly mold, and funky fungus, there’s rust. Don’t worry about being all wet — we have solutions.
Basement water collection systems: The sump pump
The most common and effective basement water collection system is the sump pump. Basement water is directed, via drainage trenches and/or sloped floors, to a recessed cavity in the floor known as a sump. The sump cavity is outfitted with a drainage pump that draws water in the sump and pumps it up and out of the basement (or in some cases a crawlspace) to a safe discharge location. The sump pump is activated by a float valve; when the water in the sump rises, so does the valve, activating the pump. The pump continues to discharge water from the sump until the level drops enough to turn the float switch off.
Be sure to frequently check the float to ensure that it’s clean and moves freely. Every fall, check it by filling the sump with water.
Sump pumps run on 110-volt power, which often fails in heavy rains. If your system has a battery backup, make sure the battery is in good condition by running the sump a second time with the house power off. (Replacing a battery is a lot less expensive than a flooded basement.)
Check y
our owner’s manual for motor maintenance. Older sump-pump motors require minor lubrication.
The discharge line that travels up and out of the basement contains a check valve, which prevents discharge water from traveling back into the sump. This valve can occasionally become frozen shut. If, during your test, everything seems to be operational, but water remains in the sump, the check valve may need to be replaced.
What to do when it floods
Try as you might, the day may come when your basement actually floods. When that happens, you need to minimize the damage by doing the following: