I use carpet squares on the floor, that way you can remove them and shake the dirt out. Mines pretty airtight with vinyl sliding windows to keep the rain out. I used 2" foam panels they removed from windows where I work. The panels have a light brown outer steel lining so no painting, also used metal trim to seal everything up. Only exposed wood is the base and under side. I have shelves on the inside and each window has ledge for a bag to shoot from. Top half is lined with black ceiling tiles to help reduce the noise and also makes the inside dark. Mines just a one person blind maybe 4 x 4 inside dimensions, but my brother's is 4 x 8 because usually there's two adults and his granddaughter hunting out of it. We do use that camo looking mesh sorta like curtains over the windows to hide your movement.