gaps between the wooden floorboards

I've used this stuff very successfuly:

This filler also takes to a dab of acrilic paint so you can change it's colour to match the wood scheme.

-- JJ

Have you looked at the FAQ?

White sealant will look vile IMO.

You also need to choose your sealant carefully. Silicone or acrylic are not good choices and for floorboards it's better to use polyurethane (Sikaflex or similar). This is not a cheap option, but PU sets relatively hard and remains flexible, doesn't shrink, has excellent grip and can be sanded flat.

Typically PU with a darker colour than the wood is used which looks better. You may also need to caulk the gaps (using cotton scrim or paper) before sealing to reduce the loss of sealant.

In article , james

writes

We've used clear silicone sealant on one floor and its been fine for years, just need to trim it off flush when its set.

Looks like the gaps are still there but with no wind rushin through!..........

for years, just

Another option is