When the weather turns damp and coastal winds blow, nothing says comfort like a fire in the hearth.

By Michael Haigley
July 20, 2004
Terry Pommett

In coastal construction, old ways often really are better ways.As we build four fireplaces in our Nantucket project house, it'snice to talk about a category that's improved by new approaches.Early masons didn't have the advantages of weather-sealingproducts, concrete blocks, and specially designed flue liners. Yetsome time-honored considerations remain.

Pure practicality
Instead of serving as primary heating systems, fireplaces nowoffer other comforts. In places like Nantucket, tradition makesthem obligatory. But having a fireplace means poking a hole in yourroof and adding to maintenance responsibilities. In other coastallocales, you might be better served with a different focal point,such as a window with a great ocean view.

The local angle
Trust techniques that have stood the test of time. Thefireplace designs for our project house are similar to those inarea homes dating back a century or more. Local masons areintimately familiar with them. This expertise reduces thelikelihood of smoke problems at the fireplace level and waterdamage where chimneys meet the roof.

One common approach in Nantucket involves installing a leadshelf within the chimney a few courses above the roofline. Duringheavy coastal storms, the shelf provides extra defense againstwindblown rain, which can penetrate upper-level chimney bricks andcause leaks below. Water absorbed by bricks drains onto theinterior shelf and escapes through "weep holes" left betweenbricks.

Keeping it simple
It's possible to run multiple fireplaces into a singlechimney. But each fireplace must have its own route through its ownflue liner (a ceramic pipe with an opening proportionate to thesize of the fireplace). Old fireplaces fed into a single flue,increasing fire and smoke hazards. The straighter the line smokefollows from the firebox to the chimney top, the better.

The same rule of simplicity applies to the correlation of thewidth, depth, and height of the firebox; the opening of the throatto the flue; and the flue liner diameter. Keeping those elements inproportion to one another minimizes danger and maximizesefficiency.

Combine traditional savvy with modern building methods andyou'll ensure your home fires stay where they belong―in thefireplace.