A Wet Basement Can Be Fixed
Good News! You can fix a wet basement. It isn’t easy, but it’s possible and it might be necessary. If you have plans to finish off your basement to add useful living space to your home, you need your basement to become a dry basement before you spend money on finishes. This is absolutely something you want to do right the first time. Halfway measures that fail later will end up costing you lots of money later and may create mold problems hidden away in walls and floors.
If you have a basement that’s damp or even is so wet it has running water entering it (I’ve seen this several times), chances are the basement wasn’t built properly in the first place. I discuss how to build it right in my article about Building a Basement. This article is about fixing an existing condition.
Let me state here that simply “handling” the water that enters your basement and pumping it out is not really a solution. It does not fix the actual problem. It only deals with the symptom, not the illness.
The secret to a dry basement is to make sure the water never gets in, at all.
Let’s look at ways to cure the illness and not just the relieve some of the symptoms.
If you have a wet basement, I can almost guarantee you do not have proper grading (slope of the soil) around your house and you probably do not have proper waterproofing on the exterior of the basement walls. These are the usual suspects.
I’ll bet there isn’t a good footing drain at the base of your basement wall or it’s been clogged or crushed. And you probably have places where water can collect around your house walls where the final grading during construction did not provide the right slope to get the water to flow away from the house. Or the soil has “subsided” and sunken due to improper soil compaction during construction. Or there has been an excessive buildup of mulch or root mass from landscaping that causes water to puddle next to the basement walls. Do any of those sound familiar?
The most important and least costly steps you can take toward fixing a wet basement are to correct the slope of the ground around your house. Before doing anything else, you need to make sure water is draining away from the basement walls and you need to clean, fix, or add gutters and downspouts to your house. If you hate gutters and downspouts, you need to install some sort of river stone or gravel trench at the drip-line of the eave to catch the roof run-off and install a perforated pipe within the stone or gravel that slopes away to an outfall. You can’t depend on the water hitting the ground and running away on its own.
It’s best to have the downspouts discharge the rainwater, either with surface or underground pipes, far from the house and not end on simple splash blocks. Or worse yet, have the downspouts discharge right on the ground, right next to your basement wall. Any water that collects near your house will seep into the soil and eventually find its way into your basement. Water always finds a way.
The second and more difficult step toward fixing a wet basement is to dig up the soil around your house, re-waterproof the basement walls, add drainage stone, and install drain piping. This is the sure method for resolving your wet basement problem. But it will be very expensive and messy. All this digging will also force you to replace your landscaping.
But if your wet basement problem is severe and you truly want to do the job right, this may be your only option. And if your builder left you with this problem, he or she has an obligation to fix the cause of the problem and make things are the way they should have been from the start.
Once the soil has been dug away and the exterior of your basement walls is exposed, the walls must be power washed to remove all of the dirt. When the walls are clean, a high-grade waterproofing system such as Tuff-n-Dri should be applied. The traditional, painted-on black mastic that might even be on your walls already, is not good enough. Think of it as “window dressing” to make everyone feel like they waterproofed the walls. It simply is not waterproof. In fact, this product is noted as “damp-proofing” and specifically not “waterproofing” on architectural drawings so as to avoid misrepresentation and lawsuits.
The best of these higher level waterproofing systems like Tuff-n-Dri coats the wall with up to a 40 mil. asphalt emulsion that sets up to a rubbery consistency. Over that, a semi-rigid board of pressed fiberglass is installed. This board helps insulate the wall. But its more important function is that it acts as a drain, breaking up the hydrostatic pressure pressing against the wall and allowing the water to drain down to the foundation drain system. Do not let your contractor talk you into a lesser system.
If digging everything up is not a good option, there is another solution for a wet basement. You can coat the inside surface of the walls with a waterproof coating. There are paints for this, but I prefer a product called Xypex. It is a cementitious material that is troweled onto existing concrete block or reinforced concrete. It bonds to the concrete at a molecular level and forms a crystalline formation that is too dense for water molecules to pass through. In other words, it makes the wall completely waterproof. It was recently used to fix the leaks in the Neptune Pool at the Hearst Castle in California.
Unlike other waterproofing paints, Xypex can be applied to wet surfaces. The finished surface will be a light grey, stucco-like surface. The product is fairly expensive, but nowhere near the cost of digging, etc. And you can apply it yourself, if you want to save some costs.
This solution will stop water from migrating through the foundation wall. But it won’t address the problem of water entering through the gap between the wall and the basement floor slab. That should be caulked with a good silicone sealer. Caulk and cracks in the floor, too. These measures should fix your wet basement if it is caused by surface water seeping into the soil around the house and then into the basement. If your problem is due to a high water table, you might need some expert help. And the solution will not be cheap.
Do not kid yourself. There is no such thing as a basement that is only “a little wet” when you are planning on finishing it off and enjoying the added living space. Water in your basement will ruin your remodeling and plague you for years to come. It’s worth the effort and expense to solve the problem the right way.
Once the wetness problem is cured, you’ll still need to make sure your basement does not feel damp and smell musty. These are issues of air quality within the basement and really have nothing to do with water infiltration. I discuss this in my article about Building a Basement.