Meaning of T&G Floorboard 'coverage' size ?

3 Jun 2016
Reaction score
United Kingdom

I need some need T&G floorboard for a 1930's house, it currently has 5"x1" T&G boards. I look on various timer yard sites and they have boards of 150mmx25mm which is close enough, however they then state a 'Coverage' size which is usually something like 137mmx20mm. Now I can kind of understand that the tongue might be 13mm so reduce the width of the board but where is the 5mm going from on the thickness ? What does coverage mean ?

Example here:

Thanks in advice
Sponsored Links
Timber is nominal sizes which are basically 4 by 2 and whatnot.
By the time they put the saw through it you've lost a bit, then for planed wood like floorboards you lose a few more mm. Then you end up with the odd finished sizes you see in the shops.
Ah thanks for that. It would be a damn sight clearer if they advertised the real sizes then online searching would be easier.

Can't seem to find anyone who does actual 6x1 inch T&G floorboards. I would have thought there must be a fair call for them for people with older houses.

I suppose one option is to use none T&G where close sizes seem to be available. Not sure what gap to leave between them though and what the draft situation is, I'll be using carpet mind.
its actually the pre worked rough sawn quoted
planing 6x1"reduces it to around 21x143mm adding a tongue knocks it back by another say 8-10mm
Sponsored Links
If you're intending to fit carpet, why do you want T&G. If you're trying to stop draughts, then either fit 22mm chipboard, or standard floorboards, and the hardboard; oh, and a good underlay works wonders - a lot of carpet fitters will tell you it's better to spend more on the underlay than the carpet.
Hi yes the only reason for the T&G is because that is what the rest of the rooms have and I'll be patching about 8ft by 5ft of floor. Good tip about the underlay :)

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local