Laying reclaimed pine floorboards - Advice?

[Shink]

Hey guys I need some advice on floorboards. I've never done this before and have gone and bought some in a fit of optimism

The floorboards are reclaimed form a chapel. They are 50-50 4" and 5" wide. Length varies (going to sort this when I pick them up to make sure I get good lengths.

The floor is 12' by 14'. Currently there is carpet. Underneath is floorboards about 100 years old, as well as some areas of chipboard (two bits, about 20% of floor.) Underneath the boards is open joists going down to the original Victorian foundations (no basement.)

At the moment I am planning to:
- lay new boards direct on top (at 90 degrees) of old floor.
- nail through existing holes (see pics) at 300mm intervals.
- leave a 10mm expansion gap.

But...do I need a membrane of some kind? Or an underlay?

It is not really an option to lay a chipboard sub-floor as this would raise the floor up too high.

So what have I forgotten? What have I got wrong??

Many thanks in advance for the advice.

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• Shink
• 4 Aug 2010
• 1

Untitled

• Shink
• 4 Aug 2010
• 1

 

[geraldthehamster]

Hey guys I need some advice on floorboards. I've never done this before and have gone and bought some in a fit of optimism

The floorboards are reclaimed form a chapel. They are 50-50 4" and 5" wide. Length varies (going to sort this when I pick them up to make sure I get good lengths.

The floor is 12' by 14'. Currently there is carpet. Underneath is floorboards about 100 years old, as well as some areas of chipboard (two bits, about 20% of floor.) Underneath the boards is open joists going down to the original Victorian foundations (no basement.)

At the moment I am planning to:
- lay new boards direct on top (at 90 degrees) of old floor.
- nail through existing holes (see pics) at 300mm intervals.
- leave a 10mm expansion gap.

But...do I need a membrane of some kind? Or an underlay?

It is not really an option to lay a chipboard sub-floor as this would raise the floor up too high.

So what have I forgotten? What have I got wrong??

Many thanks in advance for the advice.

Untitled

• Shink
• 4 Aug 2010
• 1

Untitled

• Shink
• 4 Aug 2010
• 1

I suppose keeping the original floorboards and sanding them isn't an option, as 20% of the floor is chipboard? Can you get matching boards for the chipboarded area?

Assuming you are going to use new floorboards throughout, I would give serious consideration to taking up the old floorboards, and insulating between the joists, before fixing your new boards directly to the joists. You'll thank yourself come the winter.

If the new boards need sanding, consider sanding them individually, outside, with a belt sander, before fitting, to save the mess and discomfort of sanding the finished floor, indoors.

Cheers
Richard

Cheers
Richard

 

[WoodYouLike]

You might have problems nailing through the existing chipboard area - rubbish product to have as subfloor, plus you can not glue anything on to it.

Don't use a DPM when you install on existing floorboards or sheet material (and anyway, when you nail through it the DPM will be punctured, having no effect at all).
You could decide to forget about nailing and use self-adhesive underlayment (Elastilon, beware of copy-cats around, specially from the DIY-sheds). Might be the simplest solution for you

The expansion gap you need should be at least 15mm all around the perimeter of the floor

 

[Shink]

OK, thanks guys.

Probably won't want to remove existing boards. We're only installing in one room of the ground floor rooms. The house is in three parts - 200 yr old cottage, Victorian extension, and 1970s extension. We're putting this floor in the Victorian bit. I think a portion of the floor is concrete making Elastilon an increasingly good choice.

So, to sum up...

- replace chipboard with ply.
- insulate under original boards if possible.
- use Elastilon (not cheap, but saves on nail gun hire, I guess)
- 15mm gap
- belt sand outside (good tip!)

If I use Elastilon, what should I do about the empty old nail holes?

 

[big-all]

you are going to be lucky to get many nail holes lining up as its an old building and joist spacings would be diffirent with each room

keep in mind half the holes the nails will have been pulled through so the holes will be quite big

you also need to check the boards for size and thickness as high traffic areas will be thinner than other areas

 

[WoodYouLike]

If I use Elastilon, what should I do about the empty old nail holes?

Old nail holes in existing or reclaimed floor?

If in "new" floor, either fill them with a mix of sand-dust and special filler or leave them as a special feature?

 

[Shink]

Old nail holes in existing or reclaimed floor?

Both, really. I guess you're right, the holes will give the floor character.

Thanks again - one more set of questions:

What about damp? Does Elastilon breathe? I think some of the boards were replaced due to have rotted - albeit after 100 years or so.

I'm concerned that since the building is old(ish) that Elastilon will cause a build up of moisture and rot the joists etc.

 

[WoodYouLike]

Elastilon comes without a DPM so it can be used in all circumstances. Where a DPM is needed (on concrete floors or on existing vinyl/marley tiles) you could simply install a separate DPM sheet.

You would be better of to check if air bricks are blocked and if there is sufficient ventilation underneath the existing floorboards.

 

[Shink]

Again, thanks. It's coming together...but...

I'm thinking nailing straight down is better as floor may not be flat enough for Elastilon.

But...

There's a concrete section in the floor (1m x 50cm)...glue that, nail the rest??

 

[WoodYouLike]

Use long enough boards that overspan the concrete area - then you could get away nailing those boards and use adhesive underneath the board where it runs over the concrete.

 

[Shink]

Use long enough boards that overspan the concrete area - then you could get away nailing those boards and use adhesive underneath the board where it runs over the concrete.

Right, except I can't do that.

We want the boards running away from the window. So, looking at the pic below, the boards need to be lengthways (the window's to my left)

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• Shink
• 6 Aug 2010
• 1

Very fast replies, thanks!

 

[WoodYouLike]

Meaning the concrete part starts at the wall your board starts too, if I understand correctly?

 

[Shink]

Untitled

• Shink
• 6 Aug 2010
• 1

Excuse low tech - fastest solution

C is where the concrete is, arrows show direction of boards.

Thanks again!

 

[WoodYouLike]

Ah, low tech beats modern tech at the moment

It's a non-walking area? You could get away with just glueing there (use proper flexible adhesive and put a weight on it if the boards are a bit bowed to make sure the whole lot is properly adhered).

Looking at the high tech image it doesn't look like a non-walking area. Never in favour to recommend screwing the boards down anywhere - but in this case it might be your solution

 

[Shink]

I've nailed into concrete before - but that was a nail gun and 2x4. Will have to research how to screw into concrete.

OK, I think we have a working plan...now it's time to make a mess