All Tiger sheds are made with tongue & groove timber boards all over – no low-cost and crumbly OSB board whatsoever (not like some companies we could mention). Our timber is sustainably sourced. We use slow grown European softwood, Minimize in our woodmill to your high quality. Top quality TigerFelt® https://sidemateshed54208.wikijournalist.com/4679697/shed_4x8_secrets