I'm new to the forum. We're doing a DIY inground next year and are determining the construction method for the project. I've done a bit of research and am leaning to cinder block construciton. I would prefer no liner but don't know how realisitc it is. We have two dogs and I don't want to worry about damage. We live in Northern Ontario where winter temps can reach -40. I would love to hear from people who have been there and done it and who could offer some advice.