Family-owned chimney repair serving Stoneybrook Hills

Cleaning a brick chimney without damaging it

Cleaning brick can do more harm than the dirt it removes. BIA guidance on cleaning brickwork says to select the gentlest effective method and to try it first on a small, out-of-sight area before cleaning the whole surface.

The method is matched to the brick. BIA recommends following the brick maker's cleaning procedure where there is one and trying a bucket and brush or pressurized water before chemical cleaners. Windows, trim and metal nearby are protected, since many cleaning agents, acids in particular, attack metal.

The trial area also shows what to expect, since some cleaning methods change the look of the brick. The estimate names the cleaning method and the test area, and it lists cleaning as a separate line from any repair.

• Abrasive blasting and high-pressure water can etch joints and strip the brick face
• Steel bristle brushes can leave particles that rust
• Improperly mixed or strong acid can etch brick and dissolve mortar

The shape of a mortar joint sheds water

The finished shape of a mortar joint affects how well it keeps water out. BIA guidance on water penetration says concave, V and grapevine joints best resist water in exterior brickwork, because tooling presses the mortar against the brick into a dense, weather-tight surface.

Other profiles are meant for interior work. Flush, raked, struck and similar joints are not recommended outside, since they either leave the outer mortar unconsolidated or form small ledges where water can pond. The same guidance calls full bed joints an inherent requirement for water-resistant brickwork and says to tool joints when the mortar is thumbprint hard.

Repointed or replaced brick is tooled to a profile that sheds water. BIA maintenance guidance asks for the last layer of repointing mortar to be tooled to match the original profile, so where the existing joints are raked or flush, the estimate explains the choice between matching them and switching to a profile that keeps water out.

Loose stones on a stone veneer chimney

Some stone chimneys are built of solid stone, while others carry the stone as a veneer, one outer layer set against a framed or block chimney behind it. A stone that rocks, drops or shows an open joint around its edge has lost its bond to that backing.

Where masonry veneers a frame chimney, the Florida Building Code requires through-flashing and weep holes so water that gets behind the stone can drain back out. A veneer built without them, or with them buried in mortar, has no way to shed that water.

Our stone chimney repair service chooses between resetting stones and taking down a section. On your Stoneybrook Hills home the estimate names the stones or courses involved and which of these applies.

• A few loose stones on sound, dry backing are reset
• Wet or soft backing behind the stone is repaired first
• Missing flashing at the base means rebuilding that course
• Wide movement across the face points to a section rebuild

Weep holes and through-flashing at the base of veneer

At the bottom of a brick or stone veneer chimney there should be flashing under the first course, with small openings called weep holes just above it. Together they give water that gets behind the veneer a way out. The Florida Building Code requires both where masonry veneers a frame chimney.

Weeps are easy to spoil by accident. They get filled with caulk by someone who takes them for gaps, painted over or clogged from inside by mortar droppings. Brick Industry Association guidance treats flashing and weeps as essential details that no coating replaces, and it describes clearing clogged weeps with a thin dowel or stiff wire without damaging the flashing behind them.

Any water complaint on a veneer chimney includes a look at its base for the points below. Reopening blocked weeps, or adding them where they were left out, is priced as a separate line from the repair higher up.

• A row of open weeps just above the base flashing
• Flashing visible at the bottom course
• No caulk, paint or mortar plugging the openings