Floorboards

[Dylan123]

Hi,

I have been considering flooring my downstairs in engineered wood. However, my neighbour just has bare floorboards. The floorboards are quite nice.

3 questions on this if anyone can help?:

1. Where the old faux fireplace is, the boards are very dark - presume this is where the mortar or adhesive has discoloured the wood. I presume sanding it hard will get the old colour back? Or will I need to replace with new boards?

2. The boards are pretty much flat all over except for one ridge which appears to be one joist which is a bit higher. The chimney breast skirting is about one inch high one side then the floor slopes both ways down to the same level from this. I presume just hammer the nails in and sand it till it looks more level?

3. the house has BIG crawl space. About 6 foot one end and about 2 foot the other (built on a hill)
The textbook says always insulate the ground floor but my neighbour says it’s not too cold and that because the crawl space is very large it’s unnecessary. Thoughts on this?

many thanks. We want hard floors but I can save several thousands by using the boards.

insulating under worries me as it’s a building regs job and quite a challenge for a novice as I’m aware it needs to be perfect otherwise you get damp issues.

thanks

 

[JohnD]

bare boards are cold because of draughts coming up between the boards and under the skirtings. There is no convection and very little conduction loss. Stuffing the gaps round the edges of the room, and between the joists, with mineral fibre is effective in blocking draughts.

You leave the airbricks open and ventilate the void below the joists. This does not encourage or generate damp.

 

[teaboyjim]

bare boards are cold because of draughts coming up between the boards and under the skirtings. There is no convection and very little conduction loss. Stuffing the gaps round the edges of the room, and between the joists, with mineral fibre is effective in blocking draughts. You leave the airbricks open and ventilate the void below the joists. This does not encourage or generate damp.

Can I ask what your thoughts are on replacing wooden subfloors with concrete solid floors John?

Hi,
I have been considering flooring my downstairs in engineered wood. However, my neighbour just has bare floorboards. The floorboards are quite nice.

Would you consider replacing the wooden floor with a concrete solid floor?

 

[JohnD]

Can I ask what your thoughts are on replacing wooden subfloors with concrete solid floors John?

it's usually done where a long-term water leak or blocked ventilation has led to damp that rots the wooden floor.

very annoyingly, the floor is often filled up with rubble and concrete without repairing the leaking pipe or drain, making it a hundred times more difficult and expensive to deal with later.

 

[teaboyjim]

it's usually done where a long-term water leak or blocked ventilation has led to damp that rots the wooden floor. very annoyingly, the floor is often filled up with rubble and concrete without repairing the leaking pipe or drain, making it a hundred times more difficult and expensive to deal with later.

Do you mean to say often times hardcore and concrete are piled on top of the leak without repairing it? Surely that would lead to some other issue where the water needs to find a place to egress? I suppose it wouldn't come up through the concrete as long as damp proof membranes had been laid correctly but it might spread out laterally into other rooms that perhaps haven't got dpm

 

[JohnD]

yes, yes, yes, and they generally don't bother with dpm.

p.s.

the leak is usually in the ground so the dummies usually put the water down to "rising damp."

 

[Tigercubrider]

I would keep the boards if you can, it would save money and you could spend that on insulation?

You could fit slab insulation as a tight fit between the joists, assuming you can get under the floor.
Perhaps? Add some kind of tape or even strips of wood under the boards to seal the gaps between the boards? I don't think that would impact on ventilation, given that many people fill gaps from above then sand?

With such a big void I'd add loads of string as pull through for cables and /or seriously rewire that section before finishing the floor. While accessing the floor you could resolve the lumpy board.

People on here say that you can buy damaged/over ordered cellotex type insulation cheaply via eBay?

 

[Deleted member 174758]

1. Where the old faux fireplace is, the boards are very dark - presume this is where the mortar or adhesive has discoloured the wood. I presume sanding it hard will get the old colour back? Or will I need to replace with new boards?

Sanding will often cure it, but if it doesn't completely remove the cast you could always try wood bleach. This comes as a 2-part formulation and is very effective at removing colour

2. The boards are pretty much flat all over except for one ridge which appears to be one joist which is a bit higher. The chimney breast skirting is about one inch high one side then the floor slopes both ways down to the same level from this. I presume just hammer the nails in and sand it till it looks more level?

Yes, but you are reducing the thickness of the boards a bit, so whilst you can maybe get 5 or 6mm out that way, I'd regard that as the absolute maximum. You may find that a plane (hand, jack plane or electric planer) will hog material off faster and more controllable than a belt sander alone

3. the house has BIG crawl space. About 6 foot one end and about 2 foot the other (built on a hill)
The textbook says always insulate the ground floor but my neighbour says it’s not too cold and that because the crawl space is very large it’s unnecessary. Thoughts on this?

Insulate. If nothing else, if tightly fitted, it will provide additional draught proofing - bare planked floors can be awfully draughty unless you seal all the gaps. And even then...

Personally not that keen on Cellotex, Kingspan, etc (because of Grenfell and earlier incidents). I think I'd rather use mineral wool batting (sawn to fit)