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  • Writer's pictureLanny Freng

Egress Window Wells

A little bit about egress window wells… I see a lot of window wells that have been added post-construction. One reoccurring theme I find is that the well is not installed properly. Most wells with the exception of concrete ones do not have much structural rigidity. Meaning that they can easily be collapsed when pressure is applied from the sides if not installed correctly. To combat this these wells are designed to be installed and anchored into the basement wall. It is amazing how many of these are not anchored. Probably one of the most important steps to a long installation life is skipped repeatedly. In most cases, the hole will be dug and the area prepped for the well. There are usually 3-4 holes on each tab or lip that rests against the basement wall. These holes are for concrete lags/anchors to be run through and into the basement wall. This helps resist the forces that expansive soils and frost can put on the well from the sides. When these anchors are not present over time the well will push in and if close enough come in contact with the window frame. The further these push in the more pressure is applied to the window which will usually result in the frame deflecting and cracking. This can be a slow process but not always. I see rehabbed houses where the wells have been installed relatively recently and already the soil is pushing the sides in. Obviously, this isn’t an easy fix. The area will need to be excavated around the well again and the well repositioned and then anchored the correct way. All of this can be avoided if the installers would take an extra 30 minutes and do it right the first time. Concrete wells should be of thick enough design to withstand these same forces. Concrete can withstand great compressive forces but lateral forces are another story. Surprisingly it doesn’t take much lateral force to crack concrete. A good installation of a concrete block well will be core filled with rebar reinforcement. For poured concrete rebar is a must. I would be hesitant to install a wall less than 8″ thick. I have seen a few walls that were 6″ thick and they were not holding up well.

Another area of concern is the subsurface prep at the base of the well. If done incorrectly it can lead to water infiltrating the basement at this point. Ideally, drain tile is installed and plumbed into the drain tile system of the home if this system is present or daylighted downhill somewhere. This is a best-case scenario. If there is no drain tile the area should be excavated approximately a foot below the concrete wall opening and a porous material such as pea rock is put into to fill to the desired level. This will allow excess water to drain down through the pea rock and not directly through the new window/wall joint that has been created. Some homeowners will install clear plastic covers over the well opening which can help divert water away. Keep in mind that these need to be removable. A small child should be able to push them off so they do not become trapped in the well in an emergency situation.

The window should be flashed over the top with a drip cap and trim boards should be installed over the vertical nailing fin if present. Leaving caulking exposed to the elements and UV light can dramatically shorten its life and cause premature shrinkage and cracking so it is best to cover with some trim boards where it is exposed. Hopefully, this gives you a little more insight into egress windows. As always if you have any questions regarding homes feel free to give us a call.

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