Things You'll Need
¼-inch masonry drill bit
5-inch core drill bit for masonry
5-inch steel pipe
4-inch dryer vent pipe
Expanding foam spray
Safety glasses or goggles
Cutting through a brick wall to vent a dryer is not a difficult project, but there are a few steps and quite a few tools involved. The dryer vent house should be double-walled for better insulation and fire protection against the interior of the wall, which can be accomplished by using a 5-inch pipe and a 4-inch dryer pipe installed inside the 5-inch pipe.
Find a location between studs to run the dryer vent. Tap the wall with a hammer to find a solid sound, which is a stud, and a hollow sound, which is open space. Tap a finishing nail into the wall at one inch intervals across the hollow space to be sure the area is between studs. If the nail goes all the way in without resistance, it is between studs. If there is resistance after it goes through the sheetrock, it is hitting a stud so move it in the other direction. Find the center of the open area and tap the finishing nail in this location.
Draw a 5-inch circle with the finishing nail in the center of the circle. Hold a tape measure on the finishing nail and measure 2 ½ inches from the finishing nail all the way around the finishing nail to complete a circle. Remove the finishing nail.
Insert a core drill bit into a core drill and position the bit on the circular line. Drill out the circular section. Do not go deeper than is needed to open up the sheetrock. There may be wires or plumbing in the space and the drill bit may catch on insulation and rip it out of position. Only drill deep enough to cut through the sheetrock.
Use a utility knife to cut through insulation. Push wires out of the way, if there are any, to above or below the hole. Move plumbing lines, if there are any, to above or below the area for the hole for the dryer vent. Or change location for the dryer vent hole by moving up or down on the wall and drilling a new 5-inch hole. After removing insulation, the inside of the brick wall should be visible.
Use a pencil to trace the outline of the 5-inch hole in the sheetrock onto the exposed brick. Locate the center of the 5-inch circle and mark with a pencil.
Insert a ¼-inch masonry bit into a drill and drill a hole straight through the brick at this location. Go deep enough so the drill bit goes all the way through the brick to the outside.
Go outside and draw a 5-inch circle with the drill hole at the center of the circle. Use a core saw with a 5-inch masonry bit aligned with the edges of the circle to cut a hole through the brick. Hold the drill steady and keep it straight to prevent the bit from becoming bound in the hole or breaking.
Insert the 5-inch steel pipe through the wall. The pipe only needs to be long enough to go through the wall aligned flush with the brick on the outside of the house with an inch or two on the inside of the house.
Push the 4-inch dryer vent pipe through the 5-inch pipe. Spray dabs of expanding foam at intervals between the 5-inch pipe and 4-inch dryer vent pipe to hold the dryer vent pipe centered inside the 5-inch pipe both inside and outside. When the foam has set up, spray more foam deeper between the dryer vent pipe and the 5-inch pipe.
Insert the tube of caulk into the caulk gun. Cut the tip of the caulk on an angle with a utility knife. Push the pin attached to the caulk gun into the tip of the caulk to break the inner seal of the caulk tube. Apply a thick bead of caulk around the 5-inch pipe to seal the space to prevent leaks.
Push a dryer vent into the dryer vent pipe from the outside. Apply a bead of caulk around the back of the dryer vent to seal the dryer vent to the brick and prevent leaks. Apply a bead of caulk around the 5-inch pipe on the inside of house.
Attach the dryer vent hose to the dryer vent pipe with clamps. Seal the connection with foil tape. Patch the wall as needed.
Instead of using a hole saw to cut through the brick, you can do the same thing using a ½-inch masonry bit. Drill holes all the way around the circle as close together as possible. Use a lump hammer and cold chisel to knock out the brick and clean up the edges.
Always wear safety glasses or goggles while cutting masonry or using any power tools.