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Basement Window Wells – PART I

basement window wellsOver the next month or so we’re going to talk about several fundamental aspects of basement foundations and waterproofing. Not all houses in Washington, DC or even commercial buildings for that matter have basements. Some of those buildings are set on relatively shallow footings, generally built below the height of a frost line, but in some cases even shallower than what is required by modern code (to be above a frost line).  In Capitol Hill, Georgetown and other historic neighborhoods of Washington DC though there are thousands of buildings built in rowhome type configurations with basements. Not all of these basement areas were originally finished and even today some of those areas remain unfinished, just used for the sake of utility purposes.

The basement shown in the adjacent photo has been finished throughout, except for mechanical closets.  The back room was converted into a tool workshop.  Glass block was installed in the original window opening, allowing the opening to provide light from the outdoors, but not to provide ventilation or fresh air from the outside.  The positive trade off though here is that this opening can no longer  easily leak from precipitation and or rain. 

The outline for today’s article follows:

Using a basement to add additional interior space

In many cases, even in circumstances of finished basements, there are often utility rooms within the basement areas. These utility rooms are often used for laundry equipment, slop sinks, heating and or cooling equipment, electrical distribution panels, and boilers.

The majority of the buildings built in the historic neighborhoods of Washington DC we’re built over 100 years ago. At that time, Most of the buildings in the historic neighborhoods of Washington DC were considered sufficiently ample by the inhabitants and occupants of the buildings. In fact at that time basements were rarely considered a useful part of the building. In some cases basements were used as root cellars, but in most cases they didn’t even have floors installed, it was mostly just bare compacted dirt. The majority of the now common basement renovations didn’t happen in Washington DC historic neighborhoods until about 30 to 40 years ago.

The picture below shows a window well to a basement interior space at the exterior of the building at a granite retaining wall foundation of a building. The light well is covered with an iron grate with a mesh applied on top of the heavier steel bars. This particular grate was not installed just for security, but it was also created to prevent someone from accidentally stepping on top of the area of the well and falling down and injuring themselves.

window well

A window well to an interior finished basement space.

The foundation walls, generally surrounding the perimeter of the basement, and in some cases with internal load path footings as well, generally provide the structural bearing points of the building. These elements of the structure are considered part of the backbone and fundamental elements of the structure. The condition and upkeep of these elements is important, but basement waterproofing or damp proofing, and associated failures or defects, are also a recurring issue that is constantly discussed by building owners in Washington DC. Square footage, interior space, and building space for that matter are all very valuable here in Washington DC. Real estate is simply very expensive and for that reason, people attempt to optimize the use of all of the space they have within their property. Often people will build out parts of the basement to convert the space into children’s play areas, bedrooms for guests, or even permanent bedrooms and or offices in the basement area. Also it’s very common to find dens or rumpus rooms or living room type areas in the basement, generally not the main living rooms of the house, but often used as places for watching TV or just relaxing, more cloistered and away from the rest of the world. 

The purpose of windows and fenestration in a basement

Basements tend to be much darker space but also quieter than the upper levels of the building. For that reason sometimes they have a little bit more of a relaxed feel. basements are a bit more secluded and private.  Fenestrations within a building bridge the gap between its exterior and interior, in many ways. Nevertheless, they serve as the most vulnerable points through which heat can escape or enter, as well as light can penetrate. Addressing the escalating energy requirements of a structure necessitates the incorporation of both active and passive strategies.  

Particularly, with windows and basements, generally the below ground portion of the window area will be installed in a well, set up to essentially allow an excavation below ground to service the window. The excavated well both allows for airflow to come in and out of the window for exhaust and or fresh air intake and also allows a degree of light to enter the building. By and large though these windows can be also problematic because of their points of significant problems with water entry. The infrastructure type framework around the well must be built to drain water or moisture that accumulates in the area of the well and also must be built with a cover of some sort to prevent water from flowing directly down into the well or at least have an integral drain in the well so that water can flow away.  Yet drains are not always found in window wells.  Without a drain installed in a well, it’s extremely important that a cover is built above the drain to keep the well dry.

The picture below also shows a closer view of the inside of that window opening from the interior basement. The glass block, in addition to a higher degree of protection from leakage, also provides a higher level of security than a regular window. regular double hung or double sash windows provide significant benefits over glass block.

window interior basement

Some reasons window wells leak and prevention

Whether it be a roof leak, a plumbing drip, or a foundation leak, water in a building or a home is a big problem, scary enough to keep the occupants, residents and or building owners awake at night worried about potential problems of rainstorms or the pipe leaks associated with these problems.

The picture below shows a view of a basement window well from a wider angle. You can see that the eave of the roof projects away from the building, a little bit further away from the building then the depth of the window well. In most non wind driven rain or precipitation conditions, this will allow water to flow away from the building and not fall into or run towards the window well.

eave of the roof

The eave of the roof projects away from the building, and covers directly above the area of the window well.

A lot of the preventative types of best practices related to preventing problems, failures, and defects which result in flooding related to window wells stem from design errors and or omissions. Before a contractor is even engaged, if an architect or designer is involved in the original construction, these types of problems should be rooted out through the design itself. If the building is already built though,  it is essential that you work with a good contractor who understands the principles of waterproofing and structural building elements. If the building wasn’t designed properly and doesn’t have systems in place to channel and divert water flow away from window wells, for example, then a contractor will have to do a much more extensive type of work to retrofit existing conditions. retro-fitting is generally more complicated than the same work ceteris paribus, at the time of the original construction. 

basement window

A basement window, such as the one shown above, in a window well can only provide a fraction of the amount of outdoor light that you would expect from an above grade window.

A list of types of elements used to retrofit or build better from the beginning, follow below.

  1. Wells should generally have a drain and a hard bottom.
  2. Wells should have a roof or lid that prevents  the majority of rainfall from coming directly into the area of the well.
  3. Linear trench drains work better than traditional areaway drains, but both types of drains need to be kept clean and well maintained over the years.
  4. Keep leaves away, whether through aggressive maintenance and upkeep or through permanent design solutions.
  5. Fall protection can be helpful in some configurations, in other configurations it is required for safety, yet still often ommitted.

The next picture below shows a very common type of areaway drain in the center of the landing outside of the door. Areaway drains are often installed in paving areas, such as a concrete slab where the slab or paving area cannot drain from gravity alone. In this particular case, this is an entry access pathway, excavated below grade with a stairwell leading up to the ground level of the exterior yard of the building. Traditionally, in historic times, when most of the buildings in the historic neighborhoods of Washington, DC were built, drains were often built with cast iron. The drain shown below is made from PVC.   In addition to the round drain with a square trim around the perimeter of the round drain, there’s also a linear trench drain closer to the entry doorway.

rear entrance basement

The picture below shows a typical rear entrance to the back of a row home building. Most Washington, DC row homes with basements, in historic neighborhoods, have rear entrances similar to this one. This particular entrance though is shared between the two neighboring buildings. It was originally built with one areaway drain only. That areaway drain at this point in time is completely clogged with dirt. Even now, here in early fall, in mid-October, most of the leaves are still on the nearby trees yet the leaves that have fallen are already have drifted down into this basement stairway floor.  Tree leaves, like this are very problematic with areaway drains. Typical round areaway drains are not very large, they’re commonly only roughly six to nine inches in diameter and therein have a area of less than one half of a square foot. By comparison though linear trench drains are about 5 in x 36 in at minimum and therein have a larger rectilinear area with a lineal shape which is harder to clog.  As water builds up and washes around an area drain, leaves can pile up right in the center but with a linear trench drain, leaves have a tendency to wash to one side or the other as water runs towards that area of the drain, normally in the lower slope part of the patio or paving.

back entrance of a row home building

The next picture below shows a different basement entry. This particular basement entry has an enclosure around the perimeter and has an aluminum roof overhead. This type of assembly essentially keeps water out of that area, especially at regular and even heavy rainstorms.

basement entry

Historic masonry upkeep and preservation

To properly maintain, repair, and care for these historic buildings, a knowledge, interest and understanding of historic building principles is required.  Here in Washington DC, historic masonry buildings are extremely expensive and the amount of financial loss caused by improper repointing and low quality construction is staggering.   However, in addition to the direct financial value of the property, there is also a cultural loss when historic buildings are damaged. By comparison, consider neighboring poor cities, when historic buildings are damaged, it’s not just the loss of value to the property owner, there’s also a loss to all inhabitants and visitors of a city, present and future, who care about architecture, history, and culture.

We encourage all of our clients, and all readers of this article and to our blog in general, to prioritize the historic built environment of Washington DC and neighborhoods such as Capitol Hill, Dupont Circle, and Georgetown and become educated on on the difference between proper historic preservation versus improper work which leads to significant damage to the historic fabric of a building.

From a conservation and preservation perspective, several approaches can be taken to improve conditions related to deteriorated historic brick masonry. Primarily, lime mortar brick joints and low temperature fired soft red clay bricks should be inspected and checked on a routine maintenance schedule, either seasonally or at least annually.   If brick masonry is kept in good condition, the life of embedded wood elements can be significantly extended.  Hire a professional contractor which specializes, understands and appreciates historic construction elements and buildings.

You can learn a lot more on our blog.  Feel free to check it out.  If you have questions about the historic masonry of your building in Washington DC, contact us or fill out the webform below and drop us a line.  We will be in touch if we can help.