Wilkinson (wilkinsonplus.com) does not sell Loft Boards (Loft Panels) online, in fact they don’t sell any sheet materials online. The reason for this is the cost of delivery of these large goods is really high compared with the value of the goods.
Your local Wilkinson store may stock loft panels, though not all stores do.
However if you are looking to buy online, Wickes have now introduced a special home delivery service for bulky items meaning you can now buy Loft Panels and other chipboard flooring online from Wickes.
Another DIY Store that offer loft panels is B&Q, they also do not deliver this bulky item but they do offer you the ability to reserve and collect, meaning you want waste your time checking the individual stores for stock – You just simply check online and order there and then, the all you do is visit the store to collect your loft boards.