I recently ran a call where the homeowner didn't have any problems with water entering his basement via the floor or walls, only through his 3 window wells. I find that this is a common problem with basement windows so I decided to give some advice to homeowners on different methods to help stop leaking basement window wells.
First, you need to make sure that there is positive grade sloping away from the edge of the window well and the entire side of the foundation, otherwise you will never be able to stop groundwater from flowing directly into the window well.
Second, make sure all of the downspouts carrying away roof water are extended underground about 15 to 20' away from the foundation. This has many benefits, but in this circumstance, it prevents water from flowing directly into the window well or bleeding back through the sides of the well. The last call I was on had 2 downspouts pouring directly towards his window wells.
Third, if possible, the base of the well needs to have a surface collection drain (dry well) to drain the water away from the home. This can only be achieved if the home has positive grade away from the home. Another option is to run all the collection drains from the window wells to a meter pit to pump the water away from the home.
Fourth, add a cover to the well to divert rain water from the well during heavy rains. This is typically the first option homeowners go to; but it will only stop a minimal amount of water from entering and should only be used after the water is being properly drained away from the window.
Fifth, it is possible to install a completely enclosed window well that can be fastened and sealed to the foundation. This option will likely have a cover to run water off the top of the well as well. Typically these egress window wells are installed for emergency access out of the basement. The only downfall to this system is the sealant used to prevent water leakage around the sides. As with any sealant, over time, it might fail; so it is vital that the homeowner inspects the sealant regularly.
Sixth, my least favorite, is to channel excess water from the well through and down the basement wall into an existing drainage system. This would have to be a last case scenario. Typically a basement waterproofer will sell this option when a basement drainage system is being installed. It's never a good idea to introduce more water into the basement, but in some cases, there is no other option.
I hope this information helps. If you need help with water entering your basement through the windows, Give us a call @ 1-877-409-2837 or visit our website @ www.americanbasementsolutions.com/basement-waterproofing.html to sign up for a FREE CONSULTATION.
Thanks for reading the rambling thoughts of a basement inspector,
Larry Ralph Jr.