%0 Journal Article %T Excluding a full grid minor %A Karl Heuer %J Mathematics %D 2015 %I arXiv %X In this paper we characterise the graphs containing a $\mathbb{Z} \times \mathbb{Z}$ grid minor in a similar way as it has been done by Halin for graphs with an $\mathbb{N} \times \mathbb{Z}$ grid minor. Using our characterisation, we describe the structure of graphs without $\mathbb{Z} \times \mathbb{Z}$ grid minors in terms of tree-decompositions. %U http://arxiv.org/abs/1510.03599v2