Chimney chase repair for Lake Hart homeowners

Front and back flashing that follows the shingle maker

The downslope face of a chase gets an apron flashing that lies over the shingles, and the upslope face gets a back flashing or a cricket. Under R905.2.8.4, chimney flashing on a shingle roof is applied following the asphalt shingle manufacturer's instructions.

So the details can change with the shingle brand, and a repair should follow the instructions for the roof you actually have. A bead of tar along the joint is not flashing. It usually hides a gap rather than closing it, and it can trap water against the siding.

We look at the apron and back flashing whenever the lower chase siding is off. Your estimate states whether that flashing is reused, replaced or left for a roofer, so nobody assumes someone else handled it. If the apron has been caulked or tarred over, the old material comes off so the flashing can be judged properly.

A cricket behind a wide chase

A wide chase acts like a dam on the uphill side of the roof. Rain and leaves pile up against it, and water sits at the joint instead of running past. A cricket, also called a saddle, is a small peaked roof built behind the chase that splits the water around both sides.

Florida's residential code, in R903.2.2, wants a cricket or saddle on the uphill side of a chimney or roof penetration wider than thirty inches, measured across the slope at a right angle. The covering is sheet metal or the same material as the roof.

When we rebuild the back wall of a wide chase on your Lake Hart home, we check whether a cricket is there and whether it drains. A missing or failing one goes on the estimate as its own item, with any roofing tie-in noted.

Framing that carries the chimney load

A factory-built chimney has real weight, so the framing that holds it matters. R1005.5 of the Florida Building Code says that where joists, rafters or other structural members support a factory-built chimney, those members are designed to carry the added load.

Depending on the system, the weight of the pipe may rest on the fireplace or on a support anchored to the framing. DuraVent's DuraChimney II manual, as one example, anchors its supplementary support to nearby building framing. When chase framing that carries a support has rotted, that load has to come off safely before the wood is replaced. Temporary blocking or bracing holds things in place while old wood comes out and new wood goes in.

Our crew identifies what carries the pipe before any framing is cut. Supports tied to rotted wood are reattached to new framing sized for the load, following the chimney maker's instructions. Support work is noted on its own in the estimate, and the pipe stays braced the whole time the wood is being changed.

The paperwork worth keeping after a repair

Once a chase is repaired, most of the work is hidden behind new siding or stucco. Siding hides framing, stucco hides lath, and the next person to look at your chase will not know what is behind either unless it is written down.

Keep the paperwork with your home records. The written estimate names each layer, and any approved change adds what turned up once the chase was opened. Together they tell the next inspector, a buyer or a future repair crew what went into the wall. For homes in Lake Hart, our estimates are written layer by layer partly for this reason.

If you sell the home, those papers give the buyer's inspector answers instead of guesses. These are the details worth keeping together.

• Which faces were opened and how far
• The framing, sheathing, barrier and flashing replaced
• The siding or stucco system and the paint color
• The chimney maker and model, and any listed parts replaced