How to do Pointing

How to do pointing, re-pointing Mortar Joints

If the mortar on your wall, chimney or patio is cracked and crumbling away, it is time to grab a trowel, mix up some mortar and re-point your way into a rewarding home repair project.

Step 1: Use a cold chisel and a hammer to clean out the mortar joint to be repaired. Place the chisel next to the brick or stone and angle it toward the center of the joint before striking it with the hammer. Clear the area to a depth at least twice that of the mortar joint width. Brush away any loose material before proceeding.

Step 2: Mix clean drinkable water into the dry mortar mix. Never use chemical additives when mixing mortar for re-pointing. Mix mortar in small batches, mixing only what you can use in half an hour. Finished mortar should be a thick, butter like consistency that smooths nicely when the bottom of a trowel is run over it. For most projects a premixed Type N mortar, typically 1 part Portland cement, 1 part hydrated lime and 6 parts sand, will work fine. Unfortunately, using a cement based mortar on older structures will cause irreparable damage. If the structure is over 75 years old, consult a preservation specialist to determine the correct mortar mixture.

Step 3: Mist the brick or stone area to be re-pointed. Place a lump of prepared mortar on a plastering hawk or on the bottom of a flat trowel. Use the edge of the hawk or trowel to protect the brick or stone edge as you carefully press a thin layer of mortar into the joint using a narrow tuck-pointing trowel. Fill the joint with one quarter inch of mortar at a time. Pressing it firmly into the joint and misting the area as needed to keep it moist but not wet.

Step 4: Once the joint is filled flush with the brick or stone surface, allow it to set until a print is formed when you press your thumb into the mortar. This process may take anywhere from 30 minutes to twenty four hours.

Step 5: When the mortar is thumb-print firm use a jointing tool or dowel rod to rub the surface to smooth a shine. Lightly brush the surface with a stiff bristle brush to give the new mortar a weathered look.

Step 6: Wipe away any excess mortar from the brick or stone area and clean your tools immediately with cold water. Keep the mortar joints moist for at least a day to facilitate curing and reduce shrinking.

When the mortar is completely set, use a mixture of muriatic acid and water along with a stiff bristle brush to clean away any remaining mortar residue from the face of the brick or stone.

Loose or crumbling mortar allows moisture to seep in causing irreparable damage to both the structure and the brick or stone.

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Email us at info@you-can-fix-it.com to request new fix-it ideas. We also encourage you to add comments or suggestions below each article.