Its late Spring-early Summer, the beginning of Damp Basement Season, the homeowner’s nightmare. There’s no greater issue in real estate than water penetration into the house, usually the basement level, and what to do about it. When I bought my own house, the previous owner had installed a perimeter drain and two sump pumps, so I thought any water issues had been dealt with. But they did not keep my basement from looking like the Lower Branch of the Patapsco after the first summer thunderstorm.
Until about 60 years ago, basements were not generally considered living spaces suitable for finishing off with drywall and carpet. Old foundations, whether brick or stone or even block, naturally allow a certain amount of moisture to get through. In the older neighborhoods of Baltimore, cellars or crawlspaces have dirt floors. The vast majority of Baltimore’s housing stock was built BEMC (Before the Era of Man Cave). So whether you are looking for a home, have just bought one, or are thinking of selling, you most likely will be dealing with water issues at some point.
Here are a couple of things to look for so that you can catch problems when things are dry, before that hurricane-driven downpour builds a close relationship between you and your wetvac.
1. Look at the guttering and downspouts. Are they clean? Clogged gutters fill and overflow before they can move the water to the downspout, bringing water right next to the foundation wall. Can you see where the rainwater goes once it leaves the roof? In some areas the original builders put underground rainwater drain lines to the curb, so the downspouts may empty directly into a pipe opening right next to the house. This may have been a great idea when everything was new, but if the house is 30 years old or more, that underground drain has almost certainly become blocked, either by tree roots (and the tree could be long gone) or the drain pipe has collapsed with age and deterioration.
In years past, some builders in this area routed rainwater from rear roof gutters back into the house through pipes that connected to the main sewer line. This was an issue in my basement, because during a subsequent renovation one of those drain lines was cut off and the back gutter was emptying into a drain that went nowhere. That water had no place to go, except to bubble over and go into the ground right beside the foundation wall and then onto my basement floor.
They may not be pretty, but plastic downspout extenders that carry rainwater at least three or four feet from the foundation are the best, inexpensive, foolproof method of making sure none of that rainwater comes back in through the foundation walls.
2. Is the yard landscaped and graded to carry water away from the house? It does no good to evacuate the water four feet away from the foundation if the yard slopes and brings it all right back. That is especially true around old window wells. Old homes tend to have window wells made from brick, where both brick and mortar have cracked and now allow every drop of water to come through and have free entry right back to the foundation wall. Putting fancy coverings over the window well will do no good if the earth around it funnels every drop right back to the house.
If you can manage these rainwater issues before it penetrates the foundation, you will solve a majority of your wet basement problems. After removing my front downspouts from the old underground drains and extending them away from the foundation, discovering and dealing with the cut off drain line in back, regrading around one problem window well, and replacing one downspout with a larger version to carry off more water, the basement of my 90-year-old-home has been dry for over a decade. And as far as I know, those sump pumps STILL have never been used.
Rain water penetration is not the only source of wet basements, however. Homes have sometimes been built in areas where the ground water level is unusually high, and basements can be damp without a heavy rain to blame. This water wells up from beneath the house and finds its way through the base of foundation walls. This type of problem requires the services of your local waterproofing company. The perimeter drains and sump pumps they install will collect water below the level of the current floor and prevent the water intrusion from happening in the first place. Then it can be pumped away from the house where it will be harmless. Disclosure of such a condition by an honest Seller is the best way to make sure that a Buyer is aware of such a condition, since the water table rises and falls over time depending upon long term weather trends.