What do Ottawa painters use to fill large gaps between baseboards and uneven floors before painting?

Ottawa painters typically use paintable acrylic caulk or flexible wood filler to fill large gaps between baseboards and uneven floors, with the choice depending on the gap size and whether the floor will expand and contract. For gaps up to 6mm, high-quality paintable acrylic caulk like DAP Alex Plus or Tremco Dymonic 100 ($8 to $12 per tube) works well because it remains flexible and won't crack when Ottawa's extreme temperature swings cause floor movement.

The key challenge in Ottawa homes is that our dramatic seasonal humidity changes cause hardwood and engineered floors to expand in summer and contract in winter, sometimes by several millimetres. Rigid fillers like standard wood putty will crack and fall out within a year. For gaps larger than 6mm, painters often use a two-step approach: backing rod (foam rope) pushed into the gap first, then topped with flexible caulk. This prevents the caulk from sinking too deep and ensures proper adhesion to both the baseboard and floor edge.

For very large gaps (over 10mm), which are common in older Ottawa homes with settling foundations, painters may use paintable expanding foam followed by trimming and caulk, or install quarter-round moulding to bridge the gap entirely. The quarter-round approach costs more upfront ($3 to $8 per linear foot installed) but provides a cleaner, more permanent solution that handles significant movement.

Critical timing consideration: Never fill these gaps during Ottawa's dry winter months (December through March) when floors are at maximum contraction. Fill them in late spring or early summer when floors have expanded, or you'll end up with caulk failure when the floor swells and pushes against the filler. Always choose caulk rated for 25% joint movement or higher to handle Ottawa's seasonal extremes.

When you're ready to tackle baseboard painting with proper gap filling, you can browse experienced painting contractors through the Ottawa Construction Network directory who understand these local challenges.