Install Bathroom Vanity Against Sidewall . 5219 4th ave s, seattle, wa 98108. Position the sink into the cabinet, making sure it is perfectly fitted and connected to the drain and water pipes. Master Bath Remodel Side wall, Medicine and Medicine from www.pinterest.com Cut the holes at least 1/2 bigger than the pipes to ensure easy installation. Cut pipe holes at the back of the vanity surface using a hole saw. Common bathroom layout mistakes and how to avoid them charlottesville solutions.