HELP! Is my floor a problem?

[Chris210]

i am replacing my carpet with engineered wooden flooring; oak top. Tonight I pulled back the carpet and existing underlay and there are black lines where the original floorboard have gaps.

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• Chris210
• 9 Feb 2018

• Do I need to fill the gaps between the original floorboards?
• Do I need a sheet below my underlay?

 

[Doggit]

No, and no. it's just dust coming up from below, and the underlay and engineered wood won't be affected.

 

[Chris210]

No, and no. it's just dust coming up from below, and the underlay and engineered wood won't be affected.

Thanks. The underlay I bought says it is waterproof so it’s got an inbuilt moisture barrier, is this ok?

 

[Doggit]

Definitely.

 

[JohnD]

square edged floorboards on the ground floor are notorious for dirt and draught blowing up. Your new flooring will block mist of them, but pay attention to the gap behind the skirting which you are unlikely to block. If you remove the skirting you have more chance (it will also look neater) or you could try inserting cork strip or expanding foam.

You can get best results by removing the floorboards and insulating between the joists and especially round the edges of the room. I expect your other floors are the same. Mineral wool is very suitable as you can stuff it into irregular gaps. Airflow to ventilate the underfloor void must not be obstructed.

 

[Chris210]

We’re not looking to stay for too many years extra, so I’m using trimming instead of replacing the skirting. For this reason I’m also not replacing the original floorboards, so I guess no barrier or filler needed.

 

[Doggit]

To be honest, you've got a wood floor, and then another one on top of that; I don't think the extra insulation is going to be desperately needed.

 

[Chris210]

To be honest, you've got a wood floor, and then another one on top of that; I don't think the extra insulation is going to be desperately needed.

My house is colder than a morgue! Any opportunity to throw insulation down is a positive!

 

[JohnD]

on a wooden floor, the purpose of the insulation is mostly to block draughts and dirt. There is little heat loss by conduction or radiation through a wooden floor.

Black dust tracks on a carpet or floor are annoying, and the edges are the worst.

 

[Doggit]

I suspect the cold house is due to other issues rather that the floor, and lack of insulation underneath it.

 

[Chris210]

I suspect the cold house is due to other issues rather that the floor, and lack of insulation underneath it.

That is true, but one step at a time with DIY!

 

[John D v2.0]

on a wooden floor, the purpose of the insulation is mostly to block draughts and dirt. There is little heat loss by conduction or radiation through a wooden floor.

I'd agree that the biggest problem with timber floors is usually the draught, but the insulation makes a big difference too. Our lino was pretty draught free in the old house by its nature, but the floor level was always cold. After adding insulation it was miles better. Not worth ripping up the floor to do it unless you're in there anyway, or going to live there a long time.
I'd agree wood is much better insulator than concrete though!