Is whitewood timber suitable for loft boarding?

Question

I'm planning to part board my loft (an area about 2.5m by 2.5m) for storage and it seems like the norm is to use tongue and groove chipboard like this. However I have some concerns about it;

• The packs come in lengths of 122cm and the rows must be offset, which means a lot of sawing, which means buying a small circular saw.
• The offsets mean some half boards will only span 2 joists, spreading the weight less.
• I've seen references that the recommended max loading in lofts is 25kg/SqM. The chipboard is very heavy (13kg/SqM) which means I can store less stuff.

I'd much rather use some whitewood timber like this. It comes in lengths of 240cm so each plank is the ideal size to span 5 * 60cm joists, which is the area I want to board. I realise its more expensive but due to the relatively small area the extra cost is acceptable. My question is whether this timber is suitable for flooring? Also, it is not tongue & groove, is this relevant?

House is 1980s built in the UK.

Answer 1

If you can get the white board materials into the loft there there should be no reason that would prevent you from using them as a flooring material over your joists. Especially if all you are going to place on them are fairly light weight storage boxes and other sundry items.

The relatively narrow boards may have a tendency to individually flex a small amount between joists if you were to walk around on them. Sometimes white boards can have sizeable knots that would span a good part of the width of the board. You would want to avoid installing board like that because they could flex enough at the knot to break the board.

Answer 2

Answering my own question now that my project has finished.

I had a look at the printed catalog for the supplier and it actually had more information than the web site. The catalog said that neither the chipboard, nor the whitewood planks were structural, i.e. not suitable for load-bearing. I followed this up with a visit to the store and spoke to one of their "timber experts". He told me absolutely that neither product was suitable for standing on and would not take the weight of a person. Instead he recommended their standard floorboards, which have tongue and groove and are made from a stronger grade of wood. The floorboards are a comparable price to the whitewood.

Project is now finished and I'm very happy with the result. Feels very rigid and sturdy with no flex at all. I think this is partly due to the tongue and groove.