Chimney repair from the cap to the firebox in Dover Shores East

A thin mortar top that crumbles at the edges

Some chimney tops are not a formed crown at all. They are a layer of mortar troweled over the top course and thinned out to almost nothing at the edges. BIA guidance says feathering a cast cap to the edge should be avoided, because it cuts the thickness at the edge and raises the potential for deterioration.

The thin edge is where these tops break up. Pieces chip away, cracks open and the top course of brick is left exposed to every rain. Without an overhang, water that does run off tends to run down the faces as well.

Patching a feathered top with more thin mortar repeats the mistake. The lasting repair is a new cap with a proper shape, thickened at the sides and overhanging the faces, which BIA says reduces the potential for water penetration, and sloped as the code requires. For your Dover Shores East home, the estimate describes that shape and its materials, so you know it is not another thin layer.

Spark arrestor screens and their size

Some chimney caps carry a mesh screen around their sides. That screen is a spark arrestor, and on a masonry chimney the Florida Building Code lists what it has to meet.

A spark screen only helps while its mesh is open. Soot, creosote or leaves packed into it cut down the opening the smoke has to pass through, which works against the open area the code sets.

Where a screen is clogged, bent or rusted through, our crew checks whether cleaning will do or the cap needs replacing, and whether a replacement is sized for your flue. Screen and cap then share one priced line.

• Its open area is at least four times the open area of the flue outlet
• The screen resists heat and corrosion
• It can be reached and removed so the flue can be cleaned

Solar, gutter and roofing crews working around the chimney

Other trades spend time on the roof beside your chimney. A gutter crew may lean a ladder on the crown or cap, a roofer may bend flashing while tearing off old roofing and a solar crew may step on the chase top. Nobody means harm, but the chimney is rarely on their list.

Solar layouts deserve the most attention. Panels set right up against the chimney leave no place to stand, and every later repair to flashing, crown or cap then means moving panels first. Ask the installer to leave working room on each side of the chimney before the layout is final.

Tell us when another trade is booked. Our crew can look at the chimney before they start, so anything that needs fixing is done before their work covers it, and the estimate spells out the chimney work so it fits around theirs.

Cracks in the chimney breast inside the room

The chimney breast is the part of the chimney that shows inside the room, finished in plaster, drywall, brick or stone. A crack there can be finish movement where two materials meet, or the first visible sign of water or structural movement behind the wall.

Brick Industry Association maintenance guidance lists differential movement among the possible causes of masonry distress. It also notes that with differential movement or improper flashing the source may be hidden and found only through closer diagnosis.

Our technicians read the inside crack together with the outside of the chimney and the flue, because the cause is often not in the room at all. For your Dover Shores East home, the estimate separates the repair at the source from patching the finish, so the patch is not wasted. Any of the signs below moves a crack out of the cosmetic column.

• A brown stain or bubbling paint beside the crack
• A crack that keeps growing or reopens after patching
• A stepped or diagonal line through brick