When mortaring brick on a patio, one of the first questions is where to start laying the brick. The answer depends on the pattern you intend to use, whether your slab is the same size as a multiple of whole brick, and whether the slab has control joints. Once you have these details sorted out, you're ready to start laying your brick. Below, we show you how to lay mortared brick for a patio and provide important tips you need to get started on this DIY home improvement project.
Before You Begin: Plan Layout
If the slab is the same size as a multiple of whole bricks (including mortar joints) lay the border first, then start setting brick at the border, as shown on these pages. If the slab has control joints, start along the control joints and work toward the edges.
Joint width depends on the relation of the brick's actual size to its nominal size. Generally if the actual size of a brick is 1/2 inch shorter than its nominal size, you'll make 1/2-inch joints. If it's shorter by 3/8 inch, you'll space the bricks at 3/8 inch. You can adjust spacing for aesthetics. Cut plywood of the desired thickness for spacers.
What You Need
- Layout tools plus mason's line
- 3-pound sledgehammer
- Mixing tub
- Mason's trowel
- Rubber mallet
- Circular saw and masonry blade
- Brick set
- Mortar bag
- Striking tool
- Cordless drill
- 2x lumber
- Gravel
- Deck screws
- Mortar
- Bricks
Step 1: Spread Mortar
Start the installation by setting the edging material of your choice. Then trowel a 1/2-inch coat of mortar on a roughly 4x4-foot section of the slab and comb it with the notched edge of the trowel. Apply only the amount of mortar you can use before it sets up.
Step 2: Make Brick Guide
Tie mason's line to two bricks and set them outside the site, with the line pulled tight and parallel to the border. Use the line to guide your installation, repositioning it at least every three or four courses. Set each brick in the mortar with a slight twist, lining it up with previous bricks.
Step 3: Set Bricks
As you lay each brick, set a short piece of 2x4 on it and tap it with a rubber mallet. Check each row with a straightedge to make sure all the surfaces are on the same plane. Pull up low bricks, back-butter them with additional mortar, then reset them. Reseat those that are too high by tapping them with the mallet again. Before spreading the next section of mortar, recheck the section you've just completed.
Step 4: Mortar Joints
After you've set the entire surface, let the mortar cure. Then go back and fill the joints with mortar, squeezing them full with a mortar bag. (You can mortar the brick with a trowel, but you might get more mortar on the bricks than between them.) Shape the joints with a striking tool.
Step 5: Scrape Excess Mortar
Let the mortar set up a bit, then lift off any excess from the surface with a pointing trowel. As a final cleanup, scrub off remaining mortar with a piece of wet burlap. Let the mortar cure for three days to a week before using the patio.
How to Mortar Borders to a Slab Patio
If you're mortaring your borders to the surface of the slab instead of setting them on the side of the patio, build forms to contain them. On a new slab, remove the slab forms and reset them 1/2 inch higher than the surface. This small edge will keep the border material in place. For an existing slab, dig a trench around the slab and install new forms.
