Thanks for the replies. The wool is plastic coated, as in its in a plastic bag type cover, and i've used it as a ground cover in allotments before. It doesn't tend to become waterlogged easily as the plastic membrane, although breathable, seems to encourage run off. However, all points noted, I will reserve it for use in the allotment and general garden and continue as I do, using it as a ground cover then composting it when its past its best! So, as an alternative is plain old horticultural fleece safe to use? As already said I am looking to have it held above the plants on a framework but not much above them, a few inches, to allow airflow etc but still hopefully trap enough air to warm up the soil for the more delicate plants and to keep the worst of the frost off and encourage earlier growth. This would be removed and replaced with a much higher frame in the spring to allow netting to keep birds and my dogs off of the bog!
The main reason I was asking is because I get a meat order every month and usually get about 2-3 meter lengths of this stuff every time so quickly build up a decent amount of it!