How To Fill Masonry Joints

Masonry joints can be filled with mortar while building your patio. Mortar, which is formed by a mixture of cement, and fine sand, is an excellent raw material to bind the masonry joints between bricks or concrete blocks used to construct your patio.

The following steps will guide you fill masonry joints using the dry-mortar method.

Step 1. Measurement

Mark the area for your patio where you wish to lay down your bricks or concrete slabs, with the help of a twine and stakes. Measure the dimensions of your patio carefully to make sure that opposite sides are of equal length and the corners are at right angles. Determine the number of bricks or slabs that you will need to cover the outlined area.

Step 2. Excavation

With the help of a shovel, begin excavating by digging out the soil to achieve a sufficient depth for accommodating the concrete blocks or bricks. If you want to use concrete slabs then ensure that the depth is 6 inches deep at least. If you want to use bricks, four inches of depth is sufficient. Before you begin digging, it a good idea to contact the local maintenance in your community to detect and mark out any buried wires that might be dangerous.

Step 3. Layering

Fill the dug out area with fine gravel until the level of the layer of the gravel is 2 inches. Uniformly compact the layer of gravel with the help of a strong tamping device. The layer of gravel provides stability, aids in drainage and prevents damage.

Step 4. Dry Mortar Preparation

Prepare a mixture for the dry mortar, consisting of one part of cement to five parts of fine aggregated sand. Cover the layer of gravel with this mixture forming the dry mortar. The softness of the dry mortar allows you to make minor adjustments while leveling the bricks or concreter slabs.

Step 5. Bricks or Concrete Slabs Placement

Place the bricks or concrete slabs on the dry mortar layer in an orderly manner starting from one corner of the patio. Leave 1/8 inch between each brick or slab. Take care not to walk on the ones that have been newly positioned and lay the slabs from the dry mortar end. Use a rubber mallet to adjust the level of all the slabs evenly.

Step 6. Filling the joints

Fill the joints between the bricks or the concrete slabs with the dry mortar, with the same proportion mentioned in step 4, one part of cement and five parts of sand. The mortar will help to cushion the bricks and protect them from wear and tear. Brush off the excess mixture with the help of broom and use a water hose with a very low pressure to wet the entire area of concrete slabs or bricks.


  • It is important to let the mortar settle by not walking on your patio’s new surface for a few days.
  • Dry-mortar method is an effective way to fill the space in the masonry joints while building your patio.