Q:I just purchased a home and have noticed that I have a major problem under the house. Water is pooling up and making it a muddy mess. There are even mushrooms growing there.
My first inclination would be to install a French drain, but I want to talk with an engineer before I do that. Do you have any recommendations for plumbing engineers, someone who can tell me how they would install a drainage system?
A: Installing a French drain is a lot of work and a lot of expense, especially if you hire someone to do the work.
A French drain requires digging a trench around the house, lining the trench with plastic, placing perforated drainpipe in the trench and backfilling the whole shebang. Imagine digging a 3-foot-deep trench around the entire perimeter of even an average home. That’s a lot of dirt to move.
There may be less drastic alternatives that will produce a satisfactory result.
Your instinct to seek professional advice is right. Spending a few dollars to get an expert opinion is often money well spent and will save money and trouble in the long run.
We must confess, we’ve never heard of a “plumbing engineer.” This brings back memories of Art Carney on the old “Honeymooners” TV series. Carney’s character, Ed Norton, worked in the New York City sewers as a “sanitation engineer.” Funny thing is that these days waste disposal workers are closer to engineers than were their counterparts of the ’50s.
There are several types of professionals you could call for help. At the top of the heap would be a soils engineer. This person should be able to analyze the composition of your soil and determine why water does not percolate through it and instead ends up under the house.
Next might be a landscape architect. These professionals are experts not only in horticulture but also in soils. He or she may well be able to suggest ways for you to redirect ground water so that it doesn’t end up under the house. Oftentimes, landscape architects double as landscape contractors.
A structural and pest control expert may also be able to help. This may sound strange, but a large percentage of the infestations they see are attributable to water. Your mushroom garden in the crawl space indicates that you certainly have water.
We’d go with the soils engineer for the consultation. He or she may not be equipped to do the work but will be able to give you a number of ways to solve the problem.
An alternative we’d try before seeking a consultation is installing some solid PVC drainpipes around the house to discharge water that collects in your gutters and runs down your drainpipes away from the house. Connect the downspouts into the pipe so that the rainwater discharges well away from the foundation. This may be enough to dry out your crawl space.
First, lay the pipe on top of the soil to see if this is the solution. If it works, bury the pipe about 6 inches in the ground, making sure that it falls about 1/4 inch for each 10 feet of run. Run it so that the water discharges into a dry well or onto the lawn. A dry well is a gravel-lined hole that accepts water discharged from the pipes and eventually percolates into the soil.
Be sure to place the dry well downgrade from the house. This could solve the problem and save you the cost of a consultation fee and a good deal of the work, time and money to install a French drain.
