gaps between pine floorboards

[memepool]

Hi

I have average 5mm gaps between floorboards on the ground floor of a victorian terraced house in london.

There is about 1 foot underneath so the sawdust and glue idea didn't work when the sanding was being done and we were advised to leave it.
However it's not really practicle in the kitchen to have these gaps as far as I am concerned for hygene mainly. I am worried about vermin as we are right next to the river.

I know this is a common issue and have searched the archives for answers but one question remains.

Why is clear silicone sealent a bad idea?

 

[Matt Green]

Why is clear silicone sealent a bad idea?

It is a bad idea as any water in the air beneath your kitchen (next to a river) will be absorbed by the floorboards rather than pass into your kitchen. This will increase the susceptibility of the underside of your floorboards to attack by wood-boring insects.


Matt Green

 

[Gervase]

Silicone is a bad idea because you'll lose much of the ventilation under your floor, which encourages rot, and because once it's there it's there for good - it sticks like snot to an oven door. If ever you need to lift a board for access - say to plumbing, electrics or the surface below - you'll have the devil of a job cleaning up the board.
There are some good alternatives. There's a plastic strip that fits in the gap which is fairly unobtrusive; I've seen samples and it seems ideal for gaps up to 5mm. Details at http://www.stopg-p.com/.
Otherwise you can fill the gaps with wood fillets tapped into place and then planed flush with the existing boards. If you've got a bandsaw you can make your own by cutting long strips from a piece of boarding, or get a chippie in to quote for it.

 

[Lime]

Several years ago I had a similar problem in a bedroom.
I decided that the way to deal with the problem was lift every board and renail them under compression.
In this bedroom of 14ft I managed to make room for an extra complete floorboard with some space to spare.

IF you do something similar to your kitchen floor you need to ensure the underfloor is well ventilated.

 

[Penners]

There's a plastic strip that fits in the gap which is fairly unobtrusive.

Gervase - do you have any concerns that the effect of a plastic fillet would be no different from that of silicone filler?

I tend to favour wood fillets, provided they aren't glued on both sides - one side only.

 

[Gervase]

It's a 'V' shaped fillet that sits in the gap but doesn't create an airtight seal - in fact it can be lifted out and reseated in seconds. Quite a clever idea.