If your construction business is in an area where residential basements are predominant, you have an opportunity to capitalize on requirements for emergency escape and rescue openings in the form of egress window systems for all residential dwellings.
Egress means a direct method of leaving a building. An egress window in a residential basement is a legal requirement intended to ensure that a person can escape the building during an emergency. Most local building codes also require egress windows to be large enough for a fully outfitted firefighter to enter through them for rescue.
Most communities in the United States and Canada base building codes on the International Residential Code (IRC) or the International Building Code (IBC). Section R310 of the IRC and Section 1009 of the IBC require at least one operable emergency and rescue opening in any basement plus each additional sleeping room must have its own opening. According to the IRC, an egress window must have a minimum net clear opening of 5.7 square feet and must be at least 20 inches wide and 24 inches high. The interior sill height to the finished floor must be no greater than 44 inches. If you are hired to install an egress, check first with the local code authority to see if it has its own rules or has adopted the IRC.
A typical basement egress window system consists of a window, a window well, and a window well cover. Installation of the egress window system usually requires enlargement of the opening. This is accomplished by sawing into the existing basement block or concrete wall. Common styles of egress windows have either a horizontal sliding window sash or casement-type crank-out or crank-in window sash.
Preparing to install an egress window system starts with you communicating with the homeowner to confirm the location of all utility services before digging. Other obstacles that interfere with digging and sawing, such as aerial power lines, aerial phone lines, roof overhang, down spouts, sprinkler systems, trees, branches, roots, and interior restrictions, also must be reviewed and considered. In addition, the width and height of the window and the wall thickness and type, whether it is block or poured concrete, must be confirmed.
First, mark a centerline on the wall above the window. A hole must be dug so it is centered across the window opening. The hole should be at least 4 feet wide (1 foot wider than the width of the window) and 1 foot deeper than the sill. The hole should extend out from the wall 1 foot greater than the height of the window, which would allow the window to fit inside the well, if necessary.
Prior to cutting the basement wall opening, you should contact a structural engineer to determine if a lintel or a header is required as a load-bearing building component. Basic lintels can be fabricated from an angle iron extending 6 to 8 inches past each end of the opening. A header can be made from a steel tube with steel plates welded to each end that extend down to bear on the sill plate.
Next, auger a hole into the soil in the bottom of the excavation next to the foundation at least 12 inches deep and insert a corrugated drain tile into the hole. Ideally, the drain tile should be tied into the building’s lateral foundation drainage system using a T-connector. This will serve as drainage for the window well.
Some excess drain tile should be left above the ground to be trimmed later. Fill the bottom of the excavated hole with at least 8 inches of pea gravel to 3 1/2 inches below the wall opening. Level the gravel and trim the corrugated hose just above the gravel base.
There are two types of installations for egress window systems: wood-framed and nonframed. Wood-framed installations can be used for both block and poured concrete walls. Nonframed installations can be used only for poured concrete walls.
To determine the opening size for framed installations, measure the exterior of the window frame and add 3 1/2 inches to the width and height measurements. This allows 1 1/2 inches for lumber framing and 1/4 inch for shimming and sealant on each side. For nonframed installations, measure the exterior of the window frame and add 1/2 inch to the width and height measurements. This allows 1/4 inch for shimming and sealant on each side.
To mark up the cutting area, draw a chalk line on the wall, then spray the chalk line using clear marking paint to protect it from washing away during the cutting process. Double check the distance from the sill to the finished interior floor to ensure it does not exceed 44 inches. It’s better to make two or more horizontal cuts in the concrete area, because this reduces the weight of the concrete pieces being removed.
Suitable tools for cutting an egress window opening include a wall saw, diamond chain saw, circular hand saw, or ring saw. Cut along the chalk lines using a wet-cutting concrete saw, penetrating all the way through the wall. Make sure the corners are square cut to minimize water leaks and improve the fit and finished appearance.
A wood frame is required on a block concrete wall installation. On a poured concrete wall, a wood frame may or may not be used depending on preference. To build the frame, measure the wall thickness and rip lumber to the desired width using a table saw. Lumber for the sill and header should be cut to match the dimensions of the sawed opening. Lumber for the side jambs should be measured from the head to the sill. The jambs should fit snug between the head and sill lumber. Apply sealant all the way around at the joint between the framing and the concrete or block opening, both inside and out, to ensure a watertight joint when window framework is installed.
In a concrete wall without wood framing, install the window framework by fastening it into the concrete wall with self-tapping concrete screws. For a block wall installation, fasten with rust-resistant screws using a toe-nail method through the jambs into the head and sill boards at each corner.
A helper should be positioned inside the basement to assist with window placement. Lower the window into the framed opening, inserting the bottom window edge first, then tipping in the top. Shim the window from both the interior and exterior sides until it is level, square, and flush with the exterior side of the basement wall. Take care not to damage the window with excessive shim pressure. Apply expanding foam to the window frame gap created by the shims. Allow the foam to cure for at least one hour before trimming the excess. Apply sealant around the window frame joint on both the exterior and interior sides.
Finishing the installation
The egress window well and cover now can be installed by anchoring it to the basement wall. Installation instructions will vary depending on the type of window well. In all instances, follow the manufacturer’s recommended procedures.
Backfill the window with leftover excavated dirt. The grade must slope away from the house and window well, and be at least 3 inches but no more than 12 inches below the top of the window well. Gravel can be installed over the top of the soil up to the level of the top of the window well. The egress window system installation is now complete.
Keep in mind that these are general installation guidelines only. Adherence to local code authority and manufacturer’s installation guidelines is absolutely necessary for a watertight and approved installation.
Basement window egress system installation is an opportunity for concrete contractors and concrete cutters to expand their businesses and increase their revenue streams.
Kevin Warnecke is the director of heavy user sales North America for ICS, Blount, Portland, Ore. He can be reached at 503-709-1658 or firstname.lastname@example.org.
Tom Stowell is a CSDA past president and retired vice president of sales and marketing with Norton Pro Diamond. He can be reached at 678-617-6664 or email@example.com.