Ed,
As I'm sure that you've gathered laburnum can split and you will lose some through this but at least it has been felled at the right time of year. If you can avoid cutting it into shorter lengths you will save much more of the wood. A couple of weeks ago I cut a whole tree, branch wood from 2inch upwards and some fine trunk sections. The wood had been stored outside under a weighted b and q tarpaulin and had been left undisturbed for a couple of years. The free water had dried off and the level had reduced to below 25%, the point at which I have found it safe to cut it. Best of luck but don't hurry it.
Thanks Neil for the info. This particular tree has been dead and left in situ for a couple of years now but it was cut down only last weekend .Will that fact speed up the drying time ?