Sites

Ask the Carpenter: Tips for dealing with flooded backyards

Ask the Expert Home Improvement
backyard-flooding
Water in your basement can come from a lot of places; many times it is due to lack of gutters, improper ground sloping, clogged perimeter pipes, or hydrostatic pressure. Handout

Q. I have a basement flooding issue, and I hope you have suggestions for a DIY fix. My basement door, which opens to the backyard in-ground pool area, is at the lowest part of my property. During heavy rains and especially when there is snow and rain, the basement floods. My pump-and-sandbag approach isn’t the answer.

There are several issues that are causing the flooding, including poorly designed grading down to the door and a lawn that goes right to the door jamb. The water seeps under what I suspect is a very rotted jamb.

I don’t want to spend a lot of money to fix this because I intend to sell this house in four years. The flooding happens only a handful of times a year. (I need to spend my money on updating the original avocado-colored master bath and my 1973 kitchen.)

I intend to remedy the grading issue by creating two cinder-block retaining walls on either side of the walkway to the door and filling the area with dirt so that the grade will go away from the house. I’m looking to dig down a foot, pour in crushed stone, put up the cinder-block walls, and reinforce the whole thing with rebar and concrete. I’m going to paint the dirt-facing side of the blocks with Flex Seal, per the recommendation of an employee at Home Depot. I want to add a stone facade to improve the aesthetics.

Are there better alternatives? Should I attempt to build stone retaining walls (which would be more difficult than installing a cinder-block one and probably require the help of a professional)? I don’t want this to be an eyesore; the entire pool area is dated with an old concrete pool deck, railroad tie garden walls, and a fence that is falling apart. These are updates the next homeowner might want to undertake, but I do not.

What would I do about the entryway between those hypothetical retaining walls? It will still slope down from the pool deck to the door. If I do nothing with this, water (albeit less) will still drain down into the basement in heavy rain. As this is the lowest point of the property and it’s adjacent to the pool, creating a drain will be challenging; there isn’t anywhere to drain to. I do need to dig down to get the soil away from the door jamb, but the idea of putting in an apron drain and adding a drywell at least 10 feet from the foundation and below the drain seems like a bigger project than I can manage, and would require more than digging by hand. When I dig down another foot from the jamb, the slope will be greater, and now I’m concerned that I will need steps. My husband suggested digging an outdoor sump pump area next to the door, but I’m afraid that we will end up with a submerged, frozen pump in the winter.

DONNA

A. Water in your basement can come from a lot of places; many times it is due to lack of gutters, improper ground sloping, clogged perimeter pipes, or hydrostatic pressure.

The frozen ground probably made your problem far worse because it prevented percolation.

I suggest looking closely at three things: gutters, grading, and drywells.

Gutters

Install gutters to direct water 10 feet away from your home. Gutters will capture, carry, and direct massive amounts from the basement door. Installing gutters is probably the first thing I’d try, if you don’t already have them. It’s important that the area where the gutter drains slopes away from the door area, which is not the case on your property.

Drywell

I know you don’t want to, but you should add a drainage grate in front of this door and pipe it to a drywell 5 feet deep (below the freeze line) and at least 10 feet away from house. Water entering the grate will drain away and into this drywell. The drywell, which is located below the frost layer, will hold the water, allowing it to slowly percolate back into the ground.

Grade

You can lower the grade at your door and pitch the ground away, using swales to redirect the water. A swale can easily solve standing water, flooding, and yard-drainage problems. A swale is simply a shallow ditch that uses gravity to carry off water. Swales are often wide and shallow, so you do not notice them in a lawn. I like them because they are maintenance- and electricity-free, with only one negative aspect. The longer a swale gets, the deeper it needs to be.

Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business. Send your questions to homerepair@globe.com or tweet them to @robertrobillard. Subscribe to our free real estate newsletter at pages.email.bostonglobe.com/AddressSignUp.