Hi, I have just ordered a Resilience 2 king-sized mattress. I have an Ikea wooden framed bed which has a slatted base. Two questions?

One, my bed is a continental kingsize which is slightly bigger than a UK one and my current mattress has about 2 inches spare either side as it sits on the slats, would this oversize have any adverse effects. Two, the slats are wider space than you recommend, a being about 3 inches apart, but I see Ikea has other slats, the LÖNSET and the LEIRSUND, having 26 and 39 slats respectively.

Would these do, they both look as if the slats are nearer to each other, and the more expensive one has tension adjusters for under the torso. Ps, I am a 20 stone man, not so much fat as a broad heavy ala rugby type (I wish) build.