Hardwood Stairs Installation With Gaps

Causes

• Gaps in hardwood stair installations develop when the hardwood expands and contracts at a different rate than the wooden stringers that form the stairway's structure below. This can occur if the pieces of hardwood are inserted too tightly, causing them to displace one another as they swell. It can also follow from loose installation that leaves space between hardwood planks. Damage to the stairs from dropping heavy objects or stress as a home's foundation settles can also create gaps.

Filling Gaps

• Filling gaps in hardwood stairs is not always a straightforward chore. Wood filler, which is applied while soft and later hardens, is an option, but it can crumble if the gap continues to widen as the boards pull apart. Another repair option involves inserting a thin rope into the gap. Rope will expand at a similar rate to the wood, growing to fill an enlarging gap. In cases of extreme gaps, new hardwood risers or treads may be necessary to solve the problem permanently.

Prevention

• You can prevent gaps in hardwood stairs by taking the appropriate steps before and during installation. Instead of assuming that all risers and treads are uniform, measure each space and cut custom treads that fit specific steps. Bevel the top edge of each riser for a tight seam that will minimize the appearance of a slight gap if one does develop.

Intentional Stair Gaps

• In some cases, you may wish to leave gaps between treads and risers as part of a stairway's styling. This is an option if the stairway below the hardwood installation is made of a metal frame, as in a metal spiral staircase. Gaps between treads and risers, or omitting risers altogether, gives this type of stairway a more open feel. It also eliminates the problem of irregular gaps due to swelling and expanding wood.