Landscaper Lee Gilliam heads to the Massachusetts coast to help a homeowner turn his gravel driveway into a traditional seashell lot. After marking a new layout, the two get to work using some of Lee’s specialty tools and old-fashioned hard work to excavate the driveway and spread a layer of beautiful seashells.
Next, back to the shop, landscape contractor Jenn Nawada stumps host Kevin O’Connor, general contractor Tom Silva, and heating and plumbing expert Richard Trethewey with a mystery tool. After guesses that include back massages, retirement home activities, and what could constitute hamster abuse, Jenn reveals the tool’s true purpose. Spoiler alert: things get nutty.
Finally, building engineer Ross Trethewey helps a homeowner tackle a serious problem: dangerous levels of radon gas in the home. After losing a dog to lung cancer in the non-smoking household, then noticing his neighbor’s radon mitigation system, a radon test confirmed elevated levels. Concerned for his and his new dog’s health, Ross brings in a specialist to install a system that lowers the radon levels.
How to Install a Seashell Driveway
Seashell driveways are something of a tradition in coastal areas of New England. When one homeowner decided his gravel driveway wouldn’t cut it anymore, he called the team at Ask This Old House for help installing a shell driveway of his own. Landscape contractor Lee Gilliam answered the call, helping the homeowner expand his old parking space and install a new one made from beautiful shells.
Where to find it?
Some coastal landscape supply companies have seashells in stock. The type of shells will differ based on the location of the supplier. Most companies can calculate the cubic yards if you provide the length, width, and depth of the area you would like to cover. For depth, 3 inches for a new seashell driveway and 1 inch for refreshing.
Lee used landscape marking paint and a tape measure to mark out where the driveway needed to be extended.
To remove the gravel, they used a mix of power brooms, heavy-duty rakes, shovels, and wheelbarrows.
To remove the existing stone edging, they used a pick mattock. To add the edging back they dug a small trench using a grubbing hoe.
To remove the grass between the new edging and the old, they used a sod cutter. A flat-head spade with an edger would also work.
To spread the seashells, they used a mix of transfer shovels and heavy-duty rakes. A leaf blower can blow any shells back into the driveway that went into the grass or street.
After the shells were spread, they used a plate compactor to compact the shells. A hand tamper can also be used.
What Is It? | Spiral Wire Broom
It has a handle. And a wiry-looking cage. And it’s confusing everyone in the shop. Join landscape contractor Jenn Nawada while she stumps house Kevin O’Connor, general contractor Tom Silva, and heating and plumbing expert Richard Trethewey with her new tool.
Where to find it?
How to Reduce Radon
Radon is a slow, silent killer. In fact, it’s the leading cause of lung cancer in non-smokers. When a homeowner suspected his home might have a radon issue, he called the experts at Ask This Old House. Building engineer Ross Trethewey knew how to keep the homeowner and his dog safe despite high levels of radon in the basement, calling on the help of radon mitigation technician Chris Lebreton.
Where to find it?
Expert assistance provided by: Walter Irwin Radon Mitigation & Testing
Testing: Check with your state to see if they offer free radon tests.
American Lung Association low-cost, short-term radon tests
Long-term radon monitors – Ecosense
Mitigation Companies: When hiring radon testing and mitigation experts, make sure they are certified by one of the following organizations:
The National Radon Safety Board (NRSB)
Additional Information: AARST standards for every building type
Since the radon mitigation system was installed, the homeowner has reported his continuous radon monitor has been reading an average level of 0.7pCi/l.
Well below the 12.7pCi/l average he had when Ross first arrived.
Original Air Date: Oct 2, 2025, Season 24; Ep. 2 23:42
Products and services for this episode
Most tools and materials from this episode can be found at Home Depot.
Expert assistance provided by: Walter Irwin Radon Mitigation & Testing
Mitigation Companies:
American Association of Radon Scientists and Technologists / Nation Radon Proficiency Program (AARST/NRPP)
The National Radon Safety Board (NRSB)
