Why Does Wood Crack?
Wood is a living material that expands and contracts with changes in moisture and temperature. Over time, windows, doors, floors, and outdoor decking can develop cracks, holes, and surface defects. The good news: most of these can be repaired at home without professional help — if you use the right products.
What You'll Need
- Wood filler or wood putty (depending on the size of the defect)
- Sandpaper (80–120 grit)
- A putty knife or spatula
- A brush or sponge
- Stain or varnish (if finishing is needed)
Step-by-Step: Repairing Wood Cracks
1. Prepare the Surface
Clean the repair area from dust, grease, and loose wood particles. The surface must be dry and clean. If the wood is rotten, remove all decayed material first.
2. Choose the Right Filler
For small cracks and holes, a one-component wood filler (such as Metolux 1K) works well — it's easy to apply and dries quickly. For larger defects requiring strength, use a two-component wood putty (such as Metolux 2K) — it cures through a chemical process and is significantly stronger.
For deep structural repairs (over 10 mm), an epoxy wood filler like TIMBABUILD® ERC10V is the professional choice — it can be drilled, nailed, and painted once cured.
3. Apply the Filler
Using a putty knife or spatula, fill the crack or hole with your chosen product. Apply slightly more than needed — the material may shrink slightly as it dries. Spread evenly and allow to cure according to the manufacturer's instructions.
4. Sand Smooth
Once fully cured, sand the surface with 80-grit sandpaper, then finish with 120-grit until the repair is flush with the surrounding wood.
5. Finish and Protect
You can now stain, paint, or varnish the repaired area. Metolux wood fillers accept stains and lacquers beautifully, making the repair virtually invisible.
Pro Tips for a Perfect Result
- Always work in dry conditions — moisture can prevent proper curing.
- For outdoor repairs, choose UV- and moisture-resistant products.
- Test stain colour on a small area before applying to the full repair.
- For best results on exterior joinery, prime before painting.
Summary
Repairing wood cracks doesn't have to be complicated. With the right filler and a little patience, you can restore any wooden surface and extend its life by many years. Browse our range of professional wood repair products to find the right solution for your project.