Martin SB4800 Fireplace Doors — Custom Replacement Doors Built to Order
Fireplace Doors for the Martin SB4800
The Martin SB4800 is not a typical builder-grade prefab. With a front opening around 38 inches wide and a full 27 inches tall, it belongs to Martin's large-format SB series — fireboxes built for great rooms and tall stone surrounds, where the fireplace is the wall's centerpiece rather than an afterthought. That generous opening is exactly what makes replacing its doors difficult: nothing on a hardware-store shelf comes close to covering it, and the factory that built it no longer exists.
Martin or Majestic? Read the plate first
Here is a wrinkle unique to this model: SB-series fireboxes appear in service literature under both the Martin and Majestic names. Martin Hearth & Heating documentation covers the SB series — the companion SB5400SS manual carries Martin's own warranty language — while parts catalogs list SB4800 and SB4800HB fireboxes under Majestic, with many components now marked discontinued. Both brands passed through the same corporate consolidation of the American hearth industry in the 2000s, and the practical result for you is simple: whichever name is on your rating plate, the badge matters far less than the opening in front of you. We build to measurements, not to logos. This is also not to be confused with 36- and 42-inch Martin boxes like the SA42 or BE42, which use much shorter openings.
Why the SB4800 is a harder door than most prefabs
Most 36-inch prefab fireplaces have openings around 19 to 22 inches tall. The SB4800's opening stands roughly 27 inches — a third more glass height. That extra height changes the engineering: the glass panels are larger and heavier, the frame must be stiffer to keep bi-fold panels from racking, and hinge hardware carries real load. Cheap universal doors in this size range flex, gap at the corners, and rattle in a draft. A door for this fireplace has to be built as a rigid, inside-fit unit sized to the exact opening — which is precisely the kind of door we manufacture.
What happened to Martin
Martin Industries entered Chapter 11 in December 2002, and a bankruptcy court finalized the sale of its operating assets to Monessen Hearth Systems in early 2003. The Martin Hearth & Heating name continued on some products for a time, but factory door production for these fireboxes is long finished, and parts catalogs now mark SB-series components as discontinued. Owners of an SB4800 today are firmly in custom-replacement territory — which, given the quality ceiling of the original stamped doors, is not bad news.
The right way to replace an SB4800 door
- Identify. Photograph the rating plate inside the firebox, or send a photo of the whole fireplace to our AI Fireplace Expert for identification and measuring instructions.
- Configure. Build your door in the prefab fireplace door collection — frame profile, finish, mesh, glass — and get an instant price even at this size.
- Install. The finished door is inside-fit with prefab-safe attachment: no drilling into the shell, no blocked vents, no guesswork.
Measure before anything else
Published charts put the SB4800 at 38 x 27 inches, but on a fireplace this age the chart is a starting point, not a spec sheet. Refacing projects, added stone, and settling all shift the true opening. Follow our measuring guide: width and height at three points each, smallest number wins, photo with the tape in frame. Do that and our Perfect Fit Guarantee stands behind the fit.
A word about what not to do
Because the SB4800 opening is so large, owners are often tempted by oversized masonry doors that overlap the surround. On a zero-clearance steel firebox that is the wrong move: overlap frames anchor into masonry that is not structural here, and covering the face of the box can trap heat against the shell and its cooling channels. Equally important, never drill fresh holes into the firebox to make an ill-fitting door work, and never seal off the louvers above or below the opening. Finally, treat tempered glass with respect — doors open while the fire burns, mesh closed for sparks, doors closed only as the embers die down. If a door needs any of those compromises to fit, it is the wrong door.
SB4800 questions we hear most
My rating plate says Majestic SB4800, not Martin — can you still help? Yes. The SB series appears under both names in period documentation. We build from your opening dimensions, so the door fits your firebox regardless of which badge it carries.
Are original SB4800 doors still available anywhere? Factory production ended after the 2003 asset sale, and parts references for this model are progressively marked discontinued. Surviving OEM doors in this size are rare; custom-built is the dependable route.
Does a bigger opening mean a much more expensive door? Glass area and frame size do affect price, which is why our configurator shows the number instantly as you build — no quote emails, no surprises.
Do I really need to measure if the opening is published as 38 x 27? Yes. Openings vary by installation and by decades of remodeling. Ten minutes with a tape measure is what makes an exact fit possible.
Start your SB4800 door
Configure your Martin SB4800 door online and see your price today, or send us a photo first and let our experts — available seven days a week — confirm the model and walk you through measuring. Each door leaves our shop built in the USA to your exact opening. More models are covered in our doors-by-model guide.
More Martin models we build doors for: SC36 · SF36 · SA36 · SC42 · SA42 · BE42