Removing wood mullions from windows typically involves carefully dismantling the divider that separates two or more individual window units within a larger opening. This process is most commonly performed when combining smaller window openings into a single, larger one, or during a full window replacement.
Understanding Wood Mullions vs. Muntins
Before attempting removal, it's crucial to distinguish between mullions and muntins:
- Mullions: These are vertical or horizontal structural elements that separate individual window units (or sashes) within a single window frame. They are usually more substantial and often critical to the overall stability or design of the opening.
- Muntins: Also known as window grids or grilles, these are decorative strips that divide a single pane of glass into smaller, simulated panes. They are much thinner and can often be easily removed if they are surface-mounted or between-glass.
This guide focuses on removing wood mullions. If your intention is to remove decorative muntins, the process is far simpler, often involving prying off surface-mounted strips or replacing the glass unit if they are between the panes.
Assessing Your Mullion: Structural or Non-Structural?
The most critical first step is to determine if the wood mullion is a structural supporting post or a non-structural divider.
- Non-Structural Mullions: These primarily serve to separate individual window units within a larger opening and can often be removed without compromising the building's integrity. They are common in multi-light windows where each light is a separate, smaller window.
- Structural Mullions: In some cases, a mullion might carry a load from above, acting as a supporting post for the wall or header. Removing a structural mullion without proper temporary support and reinforcement can lead to severe structural damage.
If you suspect the mullion is structural, consult a professional (structural engineer or experienced contractor) before proceeding. This guide primarily addresses the removal of non-structural wood mullions.
Essential Tools and Safety Gear
Before you begin, gather the necessary tools and prioritize safety.
Recommended Tools
| Tool Type | Purpose |
|---|---|
| Cutting Tools | Hand saw, reciprocating saw (with a wood blade), utility knife |
| Prying Tools | Pry bar, wonder bar, flat-head screwdriver (for smaller prying) |
| Demolition | Hammer, mallet |
| Measuring | Tape measure (for assessing the opening and future replacement) |
| Cleanup | Shop vacuum, broom, dustpan |
Safety Gear
- Safety Glasses: Protect your eyes from flying debris.
- Work Gloves: Prevent cuts and splinters.
- Dust Mask: Essential when cutting wood, especially in older homes where lead paint or asbestos might be present.
- Long Sleeves and Pants: Protect your skin.
Step-by-Step Guide to Removing Non-Structural Wood Mullions
The process for removing a non-structural wood mullion typically involves careful cutting and prying.
1. Preparation and Safety
- Clear the Area: Remove any furniture, window treatments, or obstacles from the vicinity of the window. Lay down drop cloths or tarps to protect flooring from debris.
- Don Safety Gear: Put on your safety glasses, gloves, and dust mask.
2. Remove Adjacent Window Sashes (If Applicable)
- If the mullion divides operational sashes, remove them first. This involves unlocking, opening, and carefully lifting them out of the frame. Removing the sashes makes the mullion more accessible and reduces potential damage to the glass.
3. Score Around the Mullion
- Using a utility knife, carefully score along all edges where the mullion meets the main window frame or the surrounding wall/trim. This breaks any paint, caulk, or sealant, preventing it from tearing adjacent surfaces when the mullion is removed. Make several passes for a clean cut.
4. Cut Through the Mullion
- For a mullion structure that is not a structural supporting post, saw completely through it using a hand saw or reciprocating saw. Identify where the mullion connects to the head and sill of the window frame. Make controlled cuts to sever these connections.
- Technique: If using a reciprocating saw, ensure the blade is long enough to pass through the entire thickness of the mullion. Start with caution, ensuring you don't cut into the main window frame if you intend to reuse it. For cleaner cuts, a hand saw might offer more control, especially in tight spaces.
5. Remove the Mullion
- Once the mullion is cut free, it's time to extract it. Remove the mullion toward the outside, to prevent damage to the interior wall surface.
- Prying: Carefully insert a pry bar between the mullion and the main window frame. Gently apply pressure to loosen it. Work your way around the mullion, prying it away from the frame bit by bit.
- Assistance: If the mullion is long or stubborn, you might need a helper to ensure it doesn't fall unexpectedly or damage the opening.
- Exterior First: Focusing on removing it towards the exterior minimizes the risk of chipping or damaging interior drywall or plaster, which is often more delicate and visible.
6. Clean Up the Opening
- With the mullion removed, you'll likely have remaining nails, screws, or wood splinters.
- Extract Fasteners: Use a hammer and pry bar to remove any remaining nails or staples.
- Smooth Edges: Use sandpaper or a wood chisel to smooth down any rough edges or splinters in the remaining frame.
- Vacuum: Thoroughly vacuum the area to remove sawdust and debris.
7. Prepare for Next Steps
- The removal of a mullion often precedes a larger project, such as installing a single, larger replacement window, or combining two smaller window openings into one continuous rough opening. At this stage, you might also need to remove the wood frame from the rough opening if you are installing a completely new, larger window unit.
- Measure the new, combined opening accurately to ensure proper fit for your new window or framing.
Considerations for Older Homes
When working on older homes, be mindful of potential issues:
- Lead Paint: If the window components are painted and the home was built before 1978, assume lead paint is present. Take extra precautions with dust containment and cleanup.
- Asbestos: While less common directly in window frames, some caulking or surrounding insulation in very old homes might contain asbestos. If in doubt, consult a professional.
- Rot/Pest Damage: Older wood can be susceptible to rot or pest damage. Inspect the remaining frame thoroughly and address any issues before installing a new window.
By following these steps, you can effectively remove non-structural wood mullions, paving the way for your next window improvement project.
