The northeast United States is old. Crazy old. So if you’re looking for advice on how to drill a hole through a wall, whether it’s above ground or below, you’ve come to the right guy.

Plumbers in the northeastern United States work on a variety of houses — new-construction homes to houses built before George Washington was born. Some structures have remarkably thick foundation walls of all types and sizes.

A common complaint from plumbers comes when you must make a wall penetration. How thick is the wall? What is the wall made of? What kind of drill bit should I use? How long should the drill bit be? How do I create a proper penetration above ground? How do I make a tight penetration below ground? How do I transition from the hole to the sleeve and the sleeve to my pipe?

Equipment availability

I don’t need to explain how to drill through wood. I’m assuming that’s a straightforward process. Drilling through 6-foot-thick rock walls, however, is another skill set. It requires strength, intelligence, careful planning and patience.

The biggest problem is the availability of drill bits. Most big box stores or local hardware stores only stock drill bits for putting in anchors for general contractors. The theory is that the big box stores will sell you the anchors and the small drill bits to install hangers and supports, your local plumbing supply wholesaler will have a similar variety of items with a few minor plumber-specific things, and anything more significant as far as coring should be done by people who have specialized equipment. You’re lucky if you live near a big box store that stocks SDS-Max shank core bits or a seller who has spline shank core bits in stock.

Since there’s a shortage of immediate suppliers, you must think ahead and be the contractor with the “specialized” equipment in stock and ready to go. This means figuring out your most common hole sizes and ordering the drill bits beforehand. The most common sizes where I work are either a 2-inch bit or a 5-inch bit since water services must be sleeved through a wall with a 1 ½-inch plastic pipe or a 2-inch gas service that must be sleeved through a 4-inch pipe (to accept LinkSeals). You’ll want those to be in some legit shank, whether the standard SDS Max shank or

Spline Shank. Something serious. You don’t want to use a small drill with a small shank and a large-diameter core bit. It will burn up the drill and take forever.

Drilling the hole

The key to drilling through a seriously thick stone wall is to let the tool do the work. Don’t let the bit overheat, try to keep the shank level and plumb during the process, and make sure you have enough wiggle room at the end of the job to slide a sleeve through straight. Leave yourself some wiggle room.

If the wall is so thick that you can’t drill through to the other side, I suggest buying a long, small-diameter pilot masonry tip for a small shank drill such as the SDS shank. If you, for example, are drilling a 5-inch hole and say you can drill in 18 inches until your drill hits the wall, you can switch to the small masonry drill with a long, small bit and drill through to the other side. After you see where it comes from the other side, you can take the big drill outside and drill in the other direction to try to meet the hole you’ve already drilled. Therefore, it’s important to oversize the core bit. If they don’t meet precisely where you want them to, you’ll have enough wiggle room to slide your sleeve in plumb and straight and hydraulic cement the outside of the sleeve. This will give you a perfect sleeve to run your utility through the wall.

Belowground penetrations

If you are making a penetration below ground, make sure you hydraulic cement or effectively seal the area between your sleeve and the foundation wall. You’ll also want to use a rubber Fernco (or whatever your local code requires) to seal between your sleeve and the utility piping you are running through the sleeve — on both sides of the wall. You’ll also need to correctly fill the hole to prevent significant settling that would put pressure down and break the hydraulic cement seal. If you’re working on a sewer line, remember to check your code for relieving arch requirements.

Aboveground penetration

If you are coming into the building above ground, you’ll need to do the same drilling technique but use a larger sleeve. For example, say you are installing a 2-inch gas line penetrating a wall. You would drill a 5-inch cored hole, install a 4-inch PVC sleeve, hydraulic cement between your PVC sleeve and the wall penetration after leveling the sleeve, and seal between the 2-inch gas line and the inside of the PVC pipe.

Here’s where commercial contractors and residential contractors differ. Residential contractors accustomed to using wall seal kits on 1-inch gas services can’t get their heads wrapped around how to seal this up. Some will try to use caulking (which looks horrible and unprofessional on a commercial building).

The answer is “pipe seal links.” There are a few different manufacturers of these super helpful seals. They are rubber wall seal links. The sizing charts will tell you how many links you need, for example, to seal up a 2-inch IPS steel line in a 4-inch-diameter hole. You order that number of links, slide it over your gas line (but inside the 4-inch PVC sleeve), and tighten the nuts that make the link seal expand in all directions, giving you a perfect seal. This is why industrial contractors use PVC as a sleeve for the links instead of the hole itself. The hole you drill won’t be perfectly drilled, making the links hard to seal, whereas the PVC is near perfect every time.

About the Author

Anthony Pacilla is a registered master plumber for McVehil Plumbing in Washington, Pennsylvania. He has over two decades of experience in the plumbing and HVAC trades, and has a bachelor’s in business and economics from Thiel College.