What is a pre-fab chimney?
Prefabricated or factory built fireplaces are genetally metal chimney systems that provide a cheaper alternative to a standard masonry chimney and has refractory fireplace panels. There are many of these in CT, especially in condominiums, townhouses, and other mass constructed residence areas. They are often surround chased with wood or siding.
What is a refractory panel?
- Description of refractory fireplace panels
- Metal firebox lined with refractory panels resembling masonry
- Manufactured with high thermal properties
- Typical thickness: 1/2 in to 3/4 in
- Four panels for back, bottom, and sides
- Purpose
- Withstand high heat, protect surrounding metal firebox
- Prevent heat transfer to metal enclosure (risk: warping, weakening)
- Prevent heat transfer to surrounding combustibles (fire hazard)
- Fire hazard explanation
- Ignition can occur without a flame, just a lowered ignition point
- Continuous heat exposure lowers ignition point of surrounding wood
- Increased risk of house fire
Why do they deteriorate?
Fireplace panels are a common repair. They are not meant to last forever. Years of heat and usage cause wear and tear, stress and heat cracks, abrasion and pitting, all of which can compromise the effectiveness of this safety barrier. They are made to be relatively easily removable and replaceable. Each manufacturer sells prefab panels for this eventuality. There are also aftermarket panels that can be cut to fit, if the make and model cannot be determined or if the fireplace is no longer made.
How do I determine what size fireplace panel I need?
Determining the correct size for your fireplace refractory panels is a straightforward—but important—step to ensure your fireplace stays safe and functions properly. Start by looking for your fireplace’s make and model number, usually found on a metal tag inside the firebox or behind the grate. This information will make ordering manufacturer-specific panels much easier, since most brands offer panels designed to fit their units precisely.
If you can’t locate the make and model (which happens more often than you’d think in older homes), you’ll need to measure the existing panels yourself. Here’s how:
- Measure each panel: Carefully measure the height, width, and thickness of the back, side, and bottom panels. Take multiple measurements in case of irregular shapes or wear.
- Double-check for fit: If the panels are damaged or warped, measure the firebox space instead to ensure your new panels won’t be too tight or too loose.
- Account for manufacturer recommendations: Many replacement panels—like those from Hargrove or Vestal—can be cut to size at home with a masonry blade if a perfect fit isn’t available.
Remember, accuracy here is key. Incorrectly sized panels can leave gaps or create unsafe conditions, so be sure to write your measurements down carefully before ordering replacements.
Should gaps between refractory panels be sealed?
A common question that comes up during panel replacement or inspection is whether the small gaps between refractory panels are a cause for concern—or if they need to be filled in with refractory cement or mortar. The answer is, in most typical installations, those hairline spaces are perfectly normal and generally do not require sealing.
Most manufacturers, including well-known brands like Hargrove and Superior, design the panels to fit snugly together with slight expansion gaps to accommodate heat-related movement. Sealing the joints can actually restrict necessary expansion and possibly cause cracking down the road. However, if there are noticeably wide gaps or missing chunks, that points to a bigger issue and should be addressed by replacing the damaged panel rather than attempting to patch up the joint with cement.
When should they be replaced?
Ideally they should be replaced before they fail completely. If the firebox becomes warped , the entire unit may need to be replaced. Prefabricated fireplaces sometimes have only a 1/2 -1 inch clearance between the fireplace and surrounding structure. Warped metal is not only compromised but may decrease those clearnaces further.
Safeside Chimney can send a CSIA Certfied Chimney Sweep to inspect the fireplace and panels during your annual routine chimney cleaning. Most cases the damage is pretty obvious and apparent. The Chimney Safety institute’s general suggested rule of thumb is to have them replaced when the surface has deteriorated a 1/4in or more , or when cracks in the panel have reached the thickness of a nickel. Spider cracks from can occur from physical stress and aren’t typically an immediate safety issue. But heat stress cracks the panels from the outside in , meaning it is cracked all the way through.
Safeside Chimney can determine the condition of the fireplace. We do the work of tracking down the manufacturers replacement panels and parts , or make the decision to order and custom cut after market products and install them , as approprate.
New Refractory panels:
- Will transform and refresh the appearance of your fireplace
- Will prevent heat from penetrating the metal firebox causing unseen damage
- Will revert the fireplace to its original safety standards
- Will reflect heat, from the fire, back into the room providing alternative heat to the home
Call Safeside today for your Prefabricate Refractory Firebox Panel Replacement
