Helping you plan your home improvement project, from start to finish

DIY Tips For How to Build An Outdoor BBQ

General Expertise
By on Mar 26, 2014
DIY Tips For How to Build An Outdoor BBQ

If you do a lot of outdoor cooking and backyard entertaining, you're probably well aware of your old gas grill's shortcomings—and the limits of your backyard. Chances are, your grill lacks any real counter space, not to mention the versatility to smoke or roast a large turkey. It probably can't generate the searing heat that you need to optimize flavor. And, if you and your grill stand alone by the garage, you've probably realized that an attractive patio might do much to improve your social life.

While there are simple ways to upgrade, like buying a larger portable grill or pouring a concrete patio slab, sometimes it makes sense to step up in style. Instead of a portable grill, we opted for a large, full-featured, built-in gas grill set into a ledgestone enclosure at the end of a cobblestone patio. It's a big project, and pricey, but the results are impressive. And we certainly won't lack for atmosphere or cooking capacity. 

Basic Ingredients

We used artificial cobblestone pavers and ledgestones. The 6 x 9-in. pavers come in several thicknesses. We chose the patio paver, which is roughly 2 3/8 in. thick. Prices vary, but expect to pay between $6 and $7 per square foot. Our grill's enclosure is made out of concrete block and brick on an 8-in.-deep concrete footing, and the masonry is finished with Cultured Stone's Pro-Fit Ledgestone veneer. We used just over 38 sq. ft. of veneer at about $6.50 per foot. For the countertop, we used five 19 x 20-in. Cultured Stone hearthstones (about $85 total).

Our built-in grill is a natural-gas unit with 493 sq. in. of primary cooking surface. It delivers up to 50,000 Btu of heat through four burners and handles slow cooking as well as quick searing for meals large and small. 

Built-in grills are permanent appliances and are subject to local building codes, especially the gas piping and electrical wiring. Because building codes can vary from region to region across the country, be sure to visit your local code authority to determine material specifications and installation regulations. If you doubt your abilities when it comes to gas or electricity, it's simply a good idea to hire a professional for this part of the job.

Breaking Ground

Get up to 4 Free Quotes!

Zip Code

First determine the size and location of your patio and stretch string lines to mark the perimeter. Remove the sod and excavate the area to about 5 in. deep for the gravel and sand bed. If the soil is heavy clay, cut it into small squares and lift it out in chunks.

Next, bring electrical conduit and gas piping to the grill area. Bore a 7/8-in. hole through the house siding and underlying rim joist. Assuming you have a finished basement, feed a fish tape into the joist space and across the basement ceiling to your service panel. Attach 12-2 w/g cable to the end of the tape and pull it back through the wall.

Thread a 4 1/2-in. pipe nipple into the back of a metal exterior box and feed the cable through this nipple. Then, insert the nipple into the hole, screw the box to the wall with 2 1/2-in. deck screws and caulk around the box.

Dig a trench between the house and the left side of the future grill enclosure. Most codes require an extension joint—a slip coupling fitted with an O-ring—in the riser between the box and the trench to accommodate any settling. To install the coupling, thread a plastic adapter into the bottom of the box and glue in a short stub of 1/2-in. plastic conduit. Then glue the top of the coupling to this stub.

Run the conduit through the trench, using elbows to make any turns. Then glue a 90° elbow to each end to form the risers. At the grill location, simply extend the riser a foot or so above grade and tape it off. On the house side, extend the riser with a length of conduit and glue this length into the bottom of the expansion coupling.

We used 5/8-in. soft copper tubing for the gas supply line. Start by boring a 3/4-in. hole through the siding and rim joist. Tape the end of the coil and insert the first few feet through the wall. Then, roll out the coil and push it through until you reach the utility room.

Cut the pipe with a tubing cutter and slide a 5/8-in. flare nut onto the protruding end. Clamp a flaring tool over the end of the pipe with about 1/8 in. of pipe showing and rotate the handle until the tool bottoms out. Remove the tool and coat the male end of a 90° flare fitting with Teflon pipe tape. Then tighten the nut on the fitting.

Lay tubing in a trench between the house and the right-rear corner of the future enclosure, taping off the far end at least 1 ft. above the ground. Join the opposite end to the 90° flare fitting and backfill the trench. Caulk around the pipe as it enters the house.

Laying the Patio

Fill the patio area with about 3 in. of 3/4-in. and smaller gravel and level it with a shovel or rake. Then, make several passes with a rented tamper. Finish by covering the rock with 1 1/2 to 2 in. of sand and tamp it as well.

We chose to lock in the pavers with an aluminum edging made by Brick Stop (Brick Stop Corp., 363 Canarctic Dr., Toronto, Ontario, Canada M3J-2P9). Using a straight line of reference—in our case the concrete steps of the house—set one paver against another. When you've reached the width you want, set the aluminum edging against the edge of the stones and nail it down with spikes—at least one every 12 in.. When working around a corner, simply bend the edging and continue. When you have a 3-ft. area of stones, work from those stones to avoid any traffic damage to the sand bed.

If you reach a point where a stone needs to be cut, measure it carefully and shape it with a circular saw fitted with a masonry blade. Test fit the cut piece and set it in place.

After you have all but the row of stones adjoining the grill enclosure in place, you're ready to build the enclosure's footing. But before you do, sweep a little sand over the stones to help stabilize them.

The Grill Enclosure

Build a 2 x 10 frame with an inside dimension of 66 x 36 in. Then, remove the soil about 8 in. overall and about 2 in. deeper at the perimeter so the form edge is at the correct height above grade. Space the form 9 1/2 in. from your last row of pavers to leave room for the final row. Use a 4-ft. level to check that the top of the form is level and flush with the top of the paving stones. Screw stakes to the form, checking across and corner to corner with the level before fastening each one. We ordered a strong half-yard of 2500 psi concrete and carried it to the form in a wheelbarrow. Pour in about half the concrete, then lay in three lengths of 1/2-in. rebar and fill the form. Screed off the excess with a 2 x 4 and run an edging tool around the perimeter. After two days, strip the forms, fill the space next to the patio with crushed rock and sand and lay the last row of stones. Install aluminum edging along the finished edge next to the footing.

Get up to 4 Free Quotes!

Zip Code

The grill mounts on a stainless steel insert sleeve. To suit the sleeve and provide adequate counter space we planned an enclosure that was four concrete blocks wide (64 in.) by two blocks deep (32 in.). We actually needed 33 in. of depth to accommodate the sleeve, so we stretched the side with wider mortar joints. Along the patio, set the blocks 1 1/2 in. inward from the edge to prevent the ledgestone veneer from overhanging the pavers.
Mix a batch of mortar and set the front row of blocks. Use a 4-ft. level to keep the blocks straight and level. Then lay the rest of the first course, leaving a half-block opening at the right-rear corner for the gas connection and another to vent the enclosure. Continue up two courses, leaving two front blocks out on the second course for the stainless steel sleeve.
To support the sleeve, set two blocks inside the enclosure, just behind the front opening. Then lay 4-in. cap blocks on the two front blocks and two interior blocks, and level them.
To achieve the correct total height—12 in. under the bottom of the sleeve and 21 1/8 in. above it—you'll need three courses of standard block, one course of concrete brick and one course of 4-in. cap block. In the event of a gas leak inside the enclosure, you'll also need to vent the enclosure at the top and bottom. The row of bricks offers the best opportunity for a vent along the top, so when laying this row, leave out several bricks and bridge the gap with cap blocks. Also, leave one brick and the cap block out on the right-front corner. This area abuts the opening in the sleeve for the gasoline.

Assemble the insert sleeve panels and fit the grill-support bars into the holes in the sleeve sides. Set the assembled sleeve into the enclosure and check the clearance for the gasline. Lay a partial brick in this area and then lay the final cap block. To provide countertop support, lay up a single-width column of bricks next to the sleeve and centered in the opening.

Cut each of the four 19 x 20-in. hearthstones for the counter to 19 x 19 in. Then cut a 3/8 x 3-in. notch in the front two hearthstones so they fit around the edge of the sleeve. Also, prepare two pieces 10 3/4 x 15 1/2 in. for the back of the grill.

Lay a loose bed of mortar on the cap blocks, tip the hearthstones under the rim of the sleeve and settle them in place, tapping them down until they're level. Position the synthetic stones so the uncut edges are visible, and don't mortar the joints at this time.

To install the ledgestone veneer, first apply at least 1/2 in. of mortar to one of the front corners with a trowel. Then, press the first corner piece into the mortar. Do the same with the course above this one, alternating the long end of the piece. Repeat this step on all four corners and begin laying courses between the corners. Where the stones meet, cut a piece to fit, mortar the back of it and press it in place. Continue until you've laid the ledgestone up to the bottom of the hearthstones. Leave the veneer off a small area above the gasline access opening for the gas regulator that comes with the grill. Finally, install vent panels over the enclosure's vent openings. We used 4-in. soffit vents, because they're the same depth as the veneer. Anchor or caulk them in place.

Installing the Grill

Have a helper on hand to ease the grill into the steel support sleeve. Then, install the door that covers the storage area below the grill and add the control knobs and other accessories.

Use plastic anchors to mount the gas regulator to the exposed block just above the gasline opening. Next, cut the copper pipe to length, install a flare fitting and gas valve, and pipe the line into the right side of the regulator with black-iron pipe. Finally, using a light coating of pipe joint compound, connect the grill's tube to the brass regulator fitting.

The connection indoors will depend on the type of gas system you have. If it's low-pressure gas—2 to 4 ounces—with the regulator on the gas meter, just connect the copper to the black-iron piping near your furnace. If it's a medium-high pressure system—about 2 pounds—you'll find the regulator indoors, usually near the furnace. All appliances need to be connected to the system after this regulator.

Shut the gas off at the regulator. Then loosen the union and thread the nipples from the low-pressure side of the regulator. Install a short nipple, a 90° L and a T and connect this assembly to the rest of the yoke with the union. Because we are splicing in a larger feed line to the grill, our gas code requires the new T feeding this line be oversize as well. To accomplish this, we used a 3/4-in. T, fitted with two 1/2-in. threaded bushings, then threaded our 1/2-in. black nipples into these bushings.

From the top of the T, install a short nipple, a gas valve and a flare fitting. Flare the copper feed line and tighten the flare nut onto the fitting. When you're finished, brush all connections with a prepared soap solution available at plumbing shops. If no bubbles appear at the connections, in the house or out, the system is tight. Check for leaks inside the grill using the manufacturer's instructions.

To complete the electrical supply, glue an exterior box to the conduit riser and screw the back of the box to the enclosure using an anchor kit. Next, pull black, white and green insulated wires through the underground conduit and tie all like-colored wires together in the box at the house using twist connectors. Ground this box and seal it with a weather-tight coverplate. Then, install a ground fault circuit interrupter (GFCI) receptacle and coverplate at the grill. At the service panel, shut the power off at the main disconnect and remove the cover. Attach the white circuit wire to the neutral bus bar and the ground wire to the grounding bus. Then snap a 20-amp breaker into the panel and tighten the black wire under its terminal screw.

Grout the joints between the hearthstones. To keep from spilling mortar on the stones, tape off both sides of each joint. Then, using fairly wet mortar, fill each joint and tool it with a tuckpoint trowel or a joint striker.

After a two-day wait, use silicone to caulk the entire perimeter of the sleeve. After the caulk has cured, brush on two thin coats of clear concrete sealer, waiting 2 hours between coats.

Step-by-Step Illustrations

  1. After removing the sod, excavate about 5 in. of soil from the patio area. If the soil is heavy clay, cut it into slabs and shovel it out.
  2. At the house, thread a nipple into the back of the box and feed the cable through this nipple and into the box.
  3. Run plastic conduit through the trench for the electrical wires. Then glue the riser into the bottom of the extension joint.
  4. Use a flaring tool to flare the ends of the copper pipe. Apply pipe dope and tighten the nuts onto a 90° flare fitting.
  5. Use a rented sand-plate tamper to level and compact the crushed rock. Make at least two passes over the entire bed.
  6. Lay out a starter row of stones. Then lock them in place with aluminum edging. Drive 10-in. spikes through the edging.
  7. Test fit the cut stones. Then set them in permanently. In this case, we had to notch around the conduit riser.
  8. Frame the enclosure footing and pour the form half-full. Lay three pieces of 1/2-in. rebar into the concrete and fill the form.
  9. Use a length of straight 2 x 4 to screed off the concrete in a sawing motion. Then use an edging tool to dress the perimeter.
  10. Finish laying the cobblestone pavers between the footing and patio. Lock them in place with aluminum edging.
  11. Lay the first course of enclosure concrete blocks on the footing. Use a 4-ft. level to straighten and level the blocks.
  12. Leave an opening in the second course and set two interior blocks to support the sides of the stainless steel grill sleeve.
  13. Finish the sleeve supports with 4-in. cap blocks. Level in all directions to make sure the grill sits level in its enclosure.
  14. Screw together the stainless steel panels of the support sleeve. Lock in the two grill-support bars before fastening the back.
  15. Lay a loose bed of mortar on top of the cap blocks to accept the hearthstones that make the enclosure's countertop.
  16. Press two corner ledgestone pieces into the wet mortar, making sure to alternate the long ends of the pieces.
  17. Lay the ledgestone from the corners to the center. Cut the last piece to fit, apply mortar and firmly press it into the opening.
  18. Vent openings are required in case of a gas leak. To keep pests from entering the enclosure, cover the openings with vent panels.
  19. After setting the grill in place on the insert, install the door that covers the storage area under the grill.
  20. Connect the grill's gas tube to the regulator behind the grill. Protect the copper riser with a length of plastic conduit.
  21. Join the new gasline to the existing piping near the furnace. Test each connection with a code-approved soap solution.
  22. After the mortar has cured, mount the new electrical box to the veneer of the enclosure with a plastic anchor kit.
  23. Grout the hearthstones with mortar and tool it with a striker or tuckpoint trowel. Tape off the stones to avoid mortar stains.
  24. Apply clear silicone caulk around the entire perimeter of the sleeve. When it cures apply two coats of sealer to the counter.

Get up to 4 Free Quotes!

Zip Code
2016 JDR Industry Blogger Award Winner for Best Microblog

You've spent some time with us! How about sharing the love in a Google review? Leave us a review