Wet hardboard?

5 Apr 2006
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United Kingdom
Good Evening

I've ordered some oak flooring and am going to tidy up the subfloor (old boards) by fitting hardboard over it.

When I ordered the hardboard and told the merchants what I was using it for they advised me to wet the hardboard before fitting it. I was a bit surprised at this advice but two different guys told me to do it.

Has anyone ever heard of this? Do you lay it wet then let it dry before fitting the oak?

Thanks in advance.
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C - hardboard is OK for under carpet and maybe vinyl to prevent 'witness marks' of the gaps between the floorboards showing through the floor covering or to reduce dust. When you say you are going to "tidy up the sub-floor", what do you mean, and why? What sort of oak flooring are you going to use? How is it going to be fixed down or is it going to 'float'?

Wetting standard hardboard is done by some in the belief that it relieves the stresses in the material so that when it is laid flat, and secured, it doesn't buckle-up. I think it's all boll**ks; if hardboard has to be used then the 'tempered' variety should be obtained.
The sub-floor is old pine boards which are a bit tatty, it's also very dusty and they aren't perfectly flat. I decided that it would be easier to lay hardboard over this than to try to tidy the actual boards themselves.

The oak I am putting down is 18mm solid oak which I will nail down using a portanailer.

I've no ideal about residual stresses in hardboard (sounds like more of a thing that would be experienced with metals) but am struggling to see the benefit in wetting it prior to laying.
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What's the best way of fixing it down to 22mm old pine? 1" nails/pins? Should I apply any glue as well?

Thanks gents
not panel pins !! Must use ring shanked nails (19-22mm) or divergent staples (19-22mm)
Dont use glue. The boards should be secured at 6" inch centers and every couple of inches around the edges. Leave a 5mm gap between all the boards edges
C - if you are keen to skin the floor before nailing your oak mark the sub-floor where your pipe and cable runs are so as to avoid driving the flooring cleats into them.

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