I ordered the 4.2 by 4.2 reject decking kit says it up to manufacturer standards but didn't quite fit the grade due to twists and knots I thought ok! I found website through google thought it looked very good and sounded like they were very helpful as call anytime for advice and stuff the decking kit came with 10 joist and said put between 300mm and 600mm apart well 300mn would only cover half decking and 600mm made decking bouncy in between boards I was not happy tried to ring customer service number and got told it's only email enquiries so emailed them which they were the most unhelpful I have ever encountered and all they kept saying was we have lots of people buying this with no problems I had bits of decking with chunks took out as well which I had to cut down which in the end led to me ordering another £100 worth of joists and decking planks which then took total to £450 errrr don't think I'll be ordering again as not very explanitary and customer service are shocking!!!!!