Most people think a basement remodel is one of the easiest home remodeling projects to complete. More typically, it is actually one of the more complex projects. Basements often have water and drainage problems, inadequate ceiling heights, old sloping concrete floor slabs, no insulation, and no easy way to connect the plumbing. Additionally, most people expect the basement to serve many purposes: often the basement is designed to accommodate work and play, media rooms, storage and craft areas, and many other uses. So unless you are looking for a simple, one-room remodel, be prepared to address a number of challenges.
Measure the basement head height
Many basements don’t have adequate floor to ceiling height to create livable space. Older homes, especially, can have inadequate head height since the space was only ever meant to be used as storage. Also, basements will often have pipes and ductwork that hang down below the floor structure of the level above. It’s often not practical to move these. So, when measuring head height, measure from the lowest objects on the ceiling. Keep in mind that if ducts and pipes are confined to one area, it may be possible to step the ceiling height so some areas are higher than others.
If the head height is not adequate, the house can be lifted up, or the basement can be dug down. Each of these options has it challenges. Lifting the house means removing items like masonry chimneys and replacing them (usually with a manufactured metal fireplace). Digging the basement down is often chosen to maintain the exterior appearance of the house, but constructing a partial new foundation under an existing foundation is difficult, time consuming, and depending on how it is done, may consume interior floor space in the new basement.
Assess how level the basement slab is
Many older homes have a poorly constructed concrete slab as the floor. Often, this slab is so out of level that one side of the basement is several inches higher than the other. Without removing the slab or pouring a topping slab to level it, it will be challenging to construct anything level and square. Plus, when furniture is moved in after construction is complete, it won’t sit flat on the floor, which will call even more attention to the problem. Spend the money to make the floor level- in the long run it will be worth it.
Be sure the basement is dry
Don’t put money and labor into a basement that is wet without solving the moisture problem. If the basement has water problems, a drainage system is the best solution to solve them. Typically, a portion of the floor slab is removed around the inside of the basement perimeter and rock and drainage pipe are installed to drain to a sump pump location where the water collects. The sump pump will periodically drain the water to the exterior when necessary. If water is coming through the center of the slab, it may be necessary to install drainage within that area of the slab, as well. It may be tempting to try some of those roll-on waterproofing systems, but usually these do not provide a lasting solution. It’s important to make a way for the water to drain away easily. Water will take the path of least resistance, so making an easy way for the water to drain is the best way to maintain a dry basement.
Insulate the basement walls and possibly the ceiling
Most jurisdictions will require the walls of the basement be insulated if you are changing the space into a living area. Usually, this is accomplished with installing 2×4 stud walls adjacent to the basement walls and installing fiberglass batts. Keep in mind that wood that is not pressure treated should not be in contact with concrete, so often the 2×4 walls are held away from the concrete so that only the bottom wall plate has to be pressure treated. Consider using a higher R-value foam insulation instead of fiberglass, which will let you reduce the thickness of the perimeter insulating walls by around 2″, which will mean more usable floor space left over. Also, a closed cell foam will act as vapor retarder, which will help keep the wall cavity dry. Unfaced fiberglass batts in the ceiling cavity will provide extra sound insulation between the different floor levels.
If you are adding a basement bathroom, assess how it will be plumbed
Many basements need an additional bathroom since it’s inconvenient to go upstairs every time you need to use the bathroom. Installing a basement bathroom can be a challenge because most basements have a concrete slab as the floor. Usually, this means cutting out portions of the slab to install drains for toilets, showers or tubs, and other fixtures. This is preferable to installing a floor on top of the slab and having a step up to use the bathroom – in the end, it will be worth the additional cost. It is also necessary to assess how the house is connected to the sewer, and the elevation of the sewer hook-up. It is easier to install a bathroom when the sewer outlet is below the level of the new basement bathroom drains. If the sewer outlet is above the basement floor (as it often is, in older homes) then the sewerage will need to be pumped up to the sewer outlet. Alarms and other safety systems should be installed to alert occupants if the pump fails, or there is a power outage.
Adding a basement bedroom?
A bedroom is a popular item to include in a basement remodel. A particular challenge of adding a bedroom is the requirement for an egress window, which is required by code and allows escape if there is a fire. As the size of this window is quite large (it is sized to allow a firefighter to gain access to the house with equipment on), the window will usually be partially or wholly below grade at the exterior. To solve this problem, a window well is constructed on the exterior of the house to allow access to the window. This has the added benefit of allowing more light into the basement, making it feel more open and connected to the outdoors. There are minimum sizes for egress windows and window wells, so following the code is important, otherwise your new basement will not pass building inspection.
Make the basement multipurpose
A basement will serve many functions, so it’s important to plan for and consider all these cases. Basements are often used as play areas for children, work areas, sleeping areas, storage areas, exercise areas, and media rooms. Consider how materials chosen for the floors and walls will aid in allowing the space be used for multiple uses. For instance, a basement floor can be quite cold, so if children are going to be playing on it, carpet may be a good choice since it has a thick insulating pad. If you want a hard surface floor, consider a floating floor of wood or cork (but keep in mind that you often have to test how much moisture is coming through the slab to see if the product will be suitable for your application).
A basement remodel is one of the most popular remodels because it can take advantage of space that is already existing. While it appears to be simple, it can be one of the more challenging projects to complete. But a well design basement often becomes the preferred ‘hang out space’, so it’s well worth the investment of time and funds. Don’t skimp on doing it right, because in the long run you will get many years of enjoyment out of a well-designed space.