🔧 BEGINNER
Quick Answer
Seal gaps around door frames with silicone caulk in 20-30 minutes per door. Cost: $8-20 for caulk and a gun. Stops cold air, insects, and noise from entering through frame gaps — one of the quickest wins in home insulation.
What You’ll Need
- Silicone caulk (clear or paintable, $8-15 at Reece or Bunnings)
- Caulking gun ($10-20 at Mitre 10)
- Craft knife or caulk scraper ($3-8 at Bunnings)
- Methylated spirits and cloth (for cleaning)
- Masking tape (optional, for clean lines)
- Damp sponge or finger for smoothing
Why Door Frame Gaps Matter in Melbourne
In SE Melbourne’s older housing stock — brick veneer homes from the 1960s-90s in Oakleigh, Springvale, and Frankston — door frames often develop gaps as the house settles over decades. These gaps are typically 2-5mm wide and run the full height of the frame on both sides.
What comes through those gaps: cold air from outside, insects (cockroaches, ants), noise from adjacent rooms or outdoors, and humidity from bathrooms or kitchens. Sealing them takes less than 30 minutes per door and costs under $20.
Step-by-Step: Sealing Door Frame Gaps
- Inspect the gap by running your finger along the frame junction — where the door frame (architrave) meets the wall. Look for cracks and gaps. Any gap over 1mm is worth sealing.
- Remove old caulk if present using a craft knife. Scrape out crumbling or peeling material completely. New caulk won’t adhere over old.
- Clean the surface with methylated spirits on a cloth. Let dry for 2-3 minutes. This removes dust, grease and old adhesive residue.
- Apply masking tape either side of the gap if you want clean lines. Cut the caulk tube at 45°, insert into gun, and test bead on scrap material first.
- Apply caulk in a steady, continuous bead along the full gap. Keep the gun moving at consistent speed — stopping creates lumps.
- Smooth with a damp finger or caulk tool. Wipe excess immediately with a damp cloth. Remove masking tape before caulk skins over (within 5 minutes).
- Allow 24 hours to cure before painting over (if using paintable caulk).
Troubleshooting
| Problem | Cause | Solution |
|---|---|---|
| Caulk won’t stick | Dirty or damp surface | Clean thoroughly with spirits and ensure surface is fully dry before applying |
| Caulk cracks after drying | Gap too wide or wrong caulk type | Use flexible silicone (not rigid acrylic) for gaps over 3mm; apply in two passes |
| Visible bead looks messy | Uneven application speed | Use masking tape either side; smooth immediately with wet finger; wipe excess |
| Gap reappears after winter | House movement (settling) | Annual re-caulking is normal for older Melbourne homes — budget 30 min per door each autumn |
When to Call a Professional
If door frames are significantly out of square, gaps are over 10mm, or the frame is rotted, you may need a carpenter. Frame replacement costs $300-800 per door in Melbourne. For cosmetic caulking gaps, DIY is always appropriate.
Tips & Gotchas
- Safety warning: Silicone caulk fumes are strong in enclosed spaces. Open windows or doors when working. Wear gloves — silicone is hard to remove from skin.
- Use paintable acrylic caulk (not silicone) if you intend to paint over it. Clear silicone takes paint poorly and shows brush marks.
- SE Melbourne’s clay soil causes more house movement than other states. Check door frame gaps every autumn — movement from the dry summer may have opened new cracks.
- Internal door frames between a wet area (bathroom, laundry) and a dry area benefit most from silicone caulk — it’s mould-resistant and flexible.
- For external door frames, use exterior-grade silicone. Interior grade degrades quickly when exposed to weather.
- Don’t caulk the gap between a door frame and the door itself — that’s where weatherstripping goes. Caulk only seals frame-to-wall gaps.
Frequently Asked Questions
Can I use gap filler (foam) instead of caulk?
Expanding foam is good for large gaps (over 10mm) but difficult to finish neatly for visible frame gaps. Use caulk for cosmetic gaps under 5mm — much easier to control and finish.
How often do door frame gaps need re-sealing?
Every 3-5 years for silicone in stable conditions. Melbourne homes on clay soil may need annual checks — house movement from seasonal moisture changes can reopen gaps.
What’s the difference between paintable and clear caulk?
Paintable acrylic caulk is for interior gaps where you’ll paint. Clear silicone is for wet areas, external frames, or where you want invisible finish. Don’t paint over clear silicone.
Local Resources (SE Melbourne)
- Bunnings Warehouse – Full caulk and sealant range, caulking guns, scrapers
- Reece Plumbing – Professional-grade silicone sealants
- Mitre 10 – Caulking guns, paintable caulk, masking tape
