Wet basement? Here's how to keep it dry in the winter and spring--and all year!
Old houses are notorious for having leaky basements, which sometimes become that way due to compromises in the foundation and/or a buildup of water around it. Even new homes can sprout unexpected leaks, unfortunately. Dampness can cause mold and mildew, whether it’s from humidity or actual leaks in concrete. Whether you live in a hundred-year-old farmhouse or a new suburban home, here are some tips to help keep your basement dry.
It’s important to shovel or blow snow away from your foundation so that a sudden melt doesn’t result in water accumulating around your foundation walls. Snow accumulation is one of those things that homeowners often miss, but a big snow can produce a lot more water than an average rain, depending on the accumulation and how fast it thaws. Regular snow removal will also prevent damage to your siding—especially if it is wood or fiberboard.
Concrete is porous and can cause dampness in your basement. A simple tape-and-foil test can show you if your basement suffers from this dampness issues. Use duct tape on a square of foil on a wall and leave it overnight. If you see a damp stain on your basement wall, it’s probably time for a dehumidifier. You can also place fans around your basement to circulate air and help dry up moisture.
Dryers can also emit humidity in your basement. Seal leaky joints in dryer ductwork with foil tape (not duct tape) and make sure dryer properly vents out a window. Condensation from pipes can also make your basement wet. Eliminate this by adding foam insulation (also see our winterizing article).
Basement Wall Paint
Obviously if you have some serious cracks or holes in cement, basement wall paint isn’t going to keep the water out. However, it does keep some dampness out and a lot of people swear by it. Drylok masonry water proofer is one of the oldest brands, but there are other products available (such as Kilz). None of it is inexpensive, but a gallon will cover about 75 square feet, and most of these products are available in 5-gallon size. Be sure wall is clean, and if you do have cracks or holes, use a fast-drying hydraulic cement patching compound (or resin patching system) to repair walls. Be sure to make repairs and allow to cure properly before applying paint. Make sure walls are dry and free of grease and other debris before painting. Note that the Drylok does not require primer and is intended to use directly over masonry. When properly applied, Drylok can dramatically reduce the dampness in your basement.
Small holes or cracks in your foundation can also cause basement dampness. Fixing them is a pretty easy DIY task using some hydraulic or even utility-grade cement. The advantage to hydraulic cement is that it drys super fast. This is great for plugging active holes, but the decreased work time can be a challenge. Be sure the surface is clean before applying and, if this isn’t something you want to tackle, you can always hire a handyman or a masonry professional. For any serious compromises to the foundation, you’ll definitely want to hire an expert.
Keeping your gutters clean keeps the water from the roof properly flowing and routed away from your house. Blockages can make the water overflow the eaves and accumulate around your foundation. If you aren’t comfortable with a ladder, this is one of those activities to leave to a pro. It generally isn’t expensive, and you might also want to investigate gutter covers as a possible solution to your gutter clutter. While not all of them are effective, the ones that are can reduce your cleaning time and cost, possibly justifying the expense in the long run. Do some smart-shopper research before investing in a gutter screen. Managing your gutters is the first step in identifying the cause for water in your basement. If your gutter system is in good order and spouts properly placed, water isn’t draining properly from around your foundation. If this is the case, you will need to think about grading and other remedies (see below).
The ground around the house needs to be properly graded to drain water away from the house. Improper grading can cause dampness in your basement. Over time, the ground can erode and require re-grading to ensure proper drainage. What, exactly, is grading? It is the slope of soil around your home (and the term also refers to the actual process of scaping the dirt to the desired angle). Positive grading is good (water drains away). Negative grading is bad as water can flow towards your house and accumulate around the foundation (and seep into your basement walls).
Sometimes grading can be adjusted by a homeowner using only a shovel and soil. Other times, the grading may require a professional (recommended) who might employ a Bobcat or other equipment to move larger quantities of soil. Just how much slope do you need around a home? Normally, you need about six inches to the first ten feet and a 5% slope. Of course, this may vary, depending on your climate and also on other structures near you and the general lay of your yard.
Be sure to keep the dirt away from your siding. You generally want 6-8 inches of foundation showing. If the dirt is too close to your siding, it can cause structural damage to your home.
Know that it matters what type of soil and materials you are grading with. Dense soil that drains is best. Avoid sand, which holds water. For persistent problems, you may need to do something more drastic (continue reading for more options).
Tip: Always contact MissDig before doing any digging around your home. You need to know where any pipes or power lines might be buried.
Window wells, if not properly placed and graded, can cause water to accumulate around your foundation. Tending to the earth and and slanting it away from the house helps, but these are known problem areas. The best solution is installing a cover like the one shown to the right. (this can be a theft deterrent as well).
Plants Around Home
Perennials or small evergreens or other shrubs around your house may absorb some of the water that might accumulate around your foundation. Before planting shrubs, however, inquire about the root system because some plant roots can grow into your foundation and cause cracking or damage, which would be counterproductive. If you hire a landscaping/excavation company to do your grading, they should be able to advise you about plants.
Gutter extensions are an inexpensive way to route water away from a house. They come in several styles, metal and plastic, including a plastic accordion type you can flex to direct the water flow. The annoying thing about extensions is trying to mow around them. Some above-ground extensions have hinge-type assemblies, so they can be folded out of the way for lawn maintenance. However, if the extensions that came with your gutter system already extend into your cutting/trimming zone, one more extension probably won’t be a bother to you.
Flat extensions are also available that spread water out once it passes through the spout. These must be placed at a proper incline in order to be effective. The benefit of these is that they are open, and you will easily notice if debris accumulates, preventing water flow.
A French ditch, often called tiling, is the underground water diverter and it is specifically used to manage water that pools below ground surface (rather than above). This is an important distinction. Although, with a little ingenuity, you can also use this type of system to route water from your spouts, as below-ground extensions, this might be overkill.
Along with foundation issues, a French ditch can be used in any problem wet area in your yard. Traditionally, the French ditch was referred to as a French drain, with a single or series of ditches routing water to the gravel drain. These terms, along with tiling, tend to be used interchangeably by contractors. In fact, a lot of them who do tiling won’t know what a French ditch is if you ask them.
One of the virtues of buried drainage is that it is not unsightly, and you can incorporate it into a landscape design. Some homeowners building underground extensions from their downspouts use solid PVC pipes, which have the benefit of keeping out dirt and debris. However, if there is debris in your gutters, it will end up in the pipe, which eventually will get clogged. Also, solid pipes don’t disperse the water as it flows through the system. They only dump it at the exit point. This might be an argument against applying the French ditch concept to gutters and downspouts. The example to the right is a perforated accordian pipe buried and extended out away from the house for drainage. The accordian gives you a lot of flexibility for routing the pipe.
Most modern French ditch systems utilize straight and/or joined PVC perforated pipe drainage systems. The pipe is wrapped with crushed stone in woven geo fabric (to keep out the dirt). Note that the fabric should be wrapped around the stone and pipe (together, not singly). This allows drainage all throughout the perforated section. There is a pre-made version of this that comes pre-wrapped in a loose “sock” with synthetic stones for drainage. Both of these options may eventually have to be replaced as the fabric breaks down over time, but this is one of the burdens of being a homeowner. Things must be replaced. Ask your contractor what the life expectancy of their French ditches are. Some of it will depend on how the pipe assemblies are wrapped. Tip: get multiple opinions and quotes, as the materials and methods will vary widely from contractor to contractor.
A depth of 18-24 inches is generally recommended, so having a power ditch digger makes the job easier, and, of course, this is one project you may prefer to hire an experienced pro for. Extended drainage is a labor-intensive DIY weekend project, but a fairly inexpensive fix to some drainage problems.
Sump pumps don’t prevent water from getting in your basement. They are often considered to be synonymous with waterproofing, but they aren’t. They also don’t prevent water from coming in; they only remove water that has entered your basement. Basement waterproofing in the form of sealing (plus, proper exterior water-routing) also needs to be done, or the deterioration to your foundation will persist, should you have a severe water problem. That said, a sump pump is a good idea in certain situations. Just make sure you get multiple opinions from contractors (ones who do exterior tiling and sump pumps) to determine which is best for your issues. The photo to the right shows sump pump with an underground drainage hose (non-perforated). The drainage end became plugged and the water started backing out of the pipe (an easy fix). When you install extensions or underground pipes you need to periodically check to make sure there are no blockages. If you notice soggy ground near a pipe line, you likely have a blockage somewhere.
Waterproofing Exterior Walls
This solution generally is better done by a professional and is the most expensive fix for wet basements. However, if you have an issue on one wall only, or in one area, it might be a feasible option, combined with a ditch, to remedy your problems. Wet basements can be tricky to fix, especially in older homes.
These tips are meant only to give you a general idea of how you might alleviate dampness and/or leaks in your basement. For serious leaking or extensive yard-levelling jobs, considering getting the opinion of a professional (or several opinions) before committing to a plan. Opinions vary, and when you’re investing a lot of time and money, you want to get the job done right.